manual de serviços sauer série 90

Axial PistonPumps and MotorsService Manual

Series 90

2Series 90 Introduction

Copyright 1987-1998, SAUER-SUNDSTRAND GmbH & Co.All rights reserved. Contents subject to change.

Introduction

Use of this Manual

S90MVCTCDS90PVMFCD

This manual includes information for the normal opera-tion, maintenance, and servicing of the Series 90 familyof hydrostatic pumps and motors.

The manual also includes the description of the units andtheir individual components, troubleshooting informa-tion, adjustment instructions, and minor repair proce-dures. Unit warranty obligations should not be affected ifmaintenance, adjustment, and minor repairs are per-formed according to the procedures described in thismanual.

Many service and adjustment activities can be performedwithout removing the unit from the vehicle or machine.However, adequate access to the unit must be available,and the unit must be thoroughly cleaned before beginningmaintenance, adjustment, or repair activities.

Since dirt and contamination are the greatest enemies ofany type of hydraulic equipment, cleanliness require-ments must be strictly adhered to. This is especiallyimportant when changing the system filter and duringadjustment and repair activities.

For further information refer to Series 90 TechnicalInformation. For information about fluid requirementsrefer to SAUER-SUNDSTRAND BLN 9887 or SDF (Id No.697581).

A worldwide network of SAUER-SUNDSTRAND Autho-rized Service Centers is available should repairs beneeded. Contact any SAUER-SUNDSTRAND Autho-rized Service Center for details. A list of all ServiceCenters can be found in bulletin BLN-2-400527, or inbrochure SAW (Ident. No. 698266).

Fluid under High Pressure

Safety Precautions

Observe the following safety precautions when using and servicing hydrostatic products.

Flammable Cleaning SolventsDisable Work Function

Loss of Hydrostatic Braking Ability

WARNINGThe loss of hydrostatic drive line power in anymode of operation (e.g., forward, reverse, or "neu-tral" mode) may cause the loss of hydrostaticbraking capacity. A braking system, redundant tothe hydrostatic transmission must, therefore, beprovided which is adequate to stop and hold thesystem should the condition develop.

S000 001E

WARNINGUse caution when dealing with hydraulic fluidunder pressure. Escaping hydraulic fluid underpressure can have sufficient force to penetrateyour skin causing serious injury. This fluid mayalso be hot enough to burn. Serious infection orreactions can develop if proper medical treat-ment is not administered immediately.

S000 003E

WARNINGSome cleaning solvents are flammable. To avoidpossible fire, do not use cleaning solvents in anarea where a source of ignition may be present.

S000 004E

WARNINGCertain service procedures may require the ve-hicle/machine to be disabled (wheels raised offthe ground, work function disconnected, etc.)while performing them in order to prevent injuryto the technician and bystanders.

S000 005E

3Series 90 ContentsContents

Introduction ......................................................................................................................................................................... 2Use of this Manual ........................................................................................................................................................................................ 2Safety Precautions ........................................................................................................................................................................................ 2Functional Description ....................................................................................................................................................... 5General Description and Cross Sectional Views ......................................................................................................................................... 5

Variable Displacement Pumps ................................................................................................................................................................ 5Fixed Displacement Motor ..................................................................................................................................................................... 5Variable Displacement Motor .................................................................................................................................................................. 6

The System Circuit ....................................................................................................................................................................................... 7The Basic Closed Circuit ........................................................................................................................................................................ 7Case Drain and Heat Exchanger ........................................................................................................................................................... 7

Common Features of Pumps and Motors .................................................................................................................................................... 8End Caps and Shafts ............................................................................................................................................................................. 8Speed Sensors ....................................................................................................................................................................................... 8

Pump Features ............................................................................................................................................................................................. 9Charge Pump .......................................................................................................................................................................................... 9Charge Relief Valve ................................................................................................................................................................................. 9Multi-Function Valves .............................................................................................................................................................................. 9

Pressure Limiter and High Pressure Relief Valves ....................................................................................................................... 10System Check Valves .................................................................................................................................................................... 10Bypass Valves ................................................................................................................................................................................ 10

Displacement Limiters .......................................................................................................................................................................... 11Auxiliary Mounting Pads ....................................................................................................................................................................... 11Filtration Options ................................................................................................................................................................................... 11Pressure Override (POR) - 180 Frame Size Only ............................................................................................................................. 12Pump Control Options .......................................................................................................................................................................... 13

Manual Displacement Control (MDC) ........................................................................................................................................... 13Hydraulic Displacement Control (HDC) ........................................................................................................................................ 13Electric Displacement Control (EDC) ............................................................................................................................................ 14Automotive Control (FBA II B) ....................................................................................................................................................... 143-Position (FNR) Electric Control .................................................................................................................................................. 14

Motor Features ........................................................................................................................................................................................... 15Motor Loop Flushing Valve and Charge Relief Valve ........................................................................................................................... 15Variable Motor Displacement Limiters .................................................................................................................................................. 15Variable Motor Controls ........................................................................................................................................................................ 16

Hydraulic 2-Position Control .......................................................................................................................................................... 16Electric 2-Position Control .............................................................................................................................................................. 16

Technical Specifications .................................................................................................................................................. 17General Specifications ................................................................................................................................................................................ 17Circuit Diagrams ......................................................................................................................................................................................... 17Hydraulic Parameters ................................................................................................................................................................................. 18Size Specific Data ....................................................................................................................................................................................... 19Pressure Measurement ................................................................................................................................................... 20Required Tools ............................................................................................................................................................................................ 20Port Locations and Pressure Gauge Installation ....................................................................................................................................... 20

Variable Pump ....................................................................................................................................................................................... 20Fixed Motor ........................................................................................................................................................................................... 23Variable Motor ....................................................................................................................................................................................... 24

Initial Start-Up Procedure ................................................................................................................................................ 25Fluid and Filter Maintenance ........................................................................................................................................... 26Troubleshooting ................................................................................................................................................................ 27"NEUTRAL" Difficult or Impossible to Find ................................................................................................................................................. 27System Operating Hot ................................................................................................................................................................................ 27Transmission Operates Normally in One Direction Only .......................................................................................................................... 28System Will Not Operate in Either Direction .............................................................................................................................................. 28Low Motor Output Torque ........................................................................................................................................................................... 29Improper Motor Output Speed .................................................................................................................................................................... 29Excessive Noise and/or Vibration .............................................................................................................................................................. 30System Response is Sluggish .................................................................................................................................................................... 30

4Series 90 ContentsInspections and Adjustments ......................................................................................................................................... 31Pump Adjustments ...................................................................................................................................................................................... 31

Charge Pressure Relief Valve Adjustment ........................................................................................................................................... 31Multi-Function Valve Pressure Adjustment .......................................................................................................................................... 33Engaging the Bypass Function ............................................................................................................................................................ 35Pressure Override (POR) Valve Pressure Adjustment (Option for 180 Frame Size) ....................................................................... 36Displacement Limiter Adjustment ......................................................................................................................................................... 37

Pump Control Adjustments ......................................................................................................................................................................... 38Standard Manual Displacement Control (MDC) Adjustment .............................................................................................................. 38Non-Linear Manual Displacement Control (MDC) .............................................................................................................................. 39MDC Neutral Start Switch (NSS) Adjustments .................................................................................................................................... 40Hydraulic Displacement Control (HDC) and Electric Displacement Control (EDC) Adjustment ....................................................... 46

Motor Adjustments ...................................................................................................................................................................................... 48Charge Relief Valve Adjustment ........................................................................................................................................................... 48Displacement Limiter Adjustment (MV) ................................................................................................................................................ 49Displacement Control Adjustments ...................................................................................................................................................... 49

Speed Sensor Adjustment .......................................................................................................................................................................... 50Minor Repair Instructions ................................................................................................................................................ 51Pump and Motor Minor Repair .................................................................................................................................................................... 53

Pump / Fitting Torques .......................................................................................................................................................................... 53Shaft Seal and Shaft Replacement ...................................................................................................................................................... 54

Pump Minor Repairs ................................................................................................................................................................................... 56Multi-Function Valve Cartridges ........................................................................................................................................................... 56Pressure Override Valve (Option for 180 Frame Size) ....................................................................................................................... 57Charge Relief Valve ............................................................................................................................................................................... 57Charge Pump - Remove ...................................................................................................................................................................... 58Installing the Charge Pump .................................................................................................................................................................. 60Auxiliary Pad Installation ....................................................................................................................................................................... 62Auxiliary Pad Conversion ..................................................................................................................................................................... 63Filtration Options ................................................................................................................................................................................... 64Pump controls ....................................................................................................................................................................................... 65

Cover Plate ..................................................................................................................................................................................... 65Manual Displacement Control (MDC) ........................................................................................................................................... 66Solenoid Override Valve for MDC .................................................................................................................................................. 67Solenoid Override Valve for MDC with Pressure Released Brake .............................................................................................. 67Hydraulic and Electric Displacement Controls ............................................................................................................................. 68Pressure Control Pilot (PCP) for Electric Displacement Control .................................................................................................. 683-Position (FNR) Electric Control .................................................................................................................................................. 69Displacement Control Components ............................................................................................................................................... 69

Minor Repair - Motor ................................................................................................................................................................................... 71Loop Flushing and Charge Relief Valves ............................................................................................................................................. 71Variable Motor Displacement Limiters .................................................................................................................................................. 73

Variable Motor Controls ............................................................................................................................................................................... 74Electrohydraulic 2-Position Control (Types NA, NB, NC, and ND) ..................................................................................................... 74Hydraulic 2-Position Control (Type PT) ............................................................................................................................................... 74Control Plugs ........................................................................................................................................................................................ 74Variable Motor Control Orifices ............................................................................................................................................................ 75

Speed Sensor .............................................................................................................................................................................................. 77Exploded View Parts Drawings / Parts Lists .................................................................................................................. 78Variable Pumps ........................................................................................................................................................................................... 78

Minor Repair Parts ................................................................................................................................................................................ 78Parts List ............................................................................................................................................................................................... 79Variable Pump Controls ........................................................................................................................................................................ 80Control Parts List .................................................................................................................................................................................. 81Filter and Options ................................................................................................................................................................................. 82Parts List Filter and Options ................................................................................................................................................................. 83Name Plates ......................................................................................................................................................................................... 83

Fixed Motor ................................................................................................................................................................................................. 84Minor Repair Parts ................................................................................................................................................................................ 84Parts List ............................................................................................................................................................................................... 85Name Plates ......................................................................................................................................................................................... 85

Variable Motor .............................................................................................................................................................................................. 86Minor Repair Parts ................................................................................................................................................................................ 86Parts List ............................................................................................................................................................................................... 87Name Plate ............................................................................................................................................................................................ 87

5Series 90 Functional DescriptionFunctional Description

This section describes the operation of pumps, motors, and their various serviceable features. It is a useful reference forreaders unfamiliar with the functioning of a specific system.

General Description and Cross Sectional Views

P001 413E

Series 90 Variable Displacement Pump (PV)

Series 90 Fixed Displacement Motor (MF)90000347

F000 539

Series 90 PV Cross Section

Variable Displacement Pumps

The Variable Displacement Pump (PV) is designed toconvert an input torque into hydraulic power. The inputshaft turns the pump cylinder which contains a ring ofpistons. The pistons run against a tilted plate, called theswashplate. This causes the pistons to compress thehydraulic fluid which imparts the input energy into thehydraulic fluid. The high pressure fluid is then ported outto provide power to a remote function.

The swashplate angle can be varied by the control piston.Altering the swashplate angle varies the displacement offluid in a given revolution of the input shaft.

Fixed Displacement Motor

The Fixed Displacement Motor (MF) is designed toconvert an input of hydraulic power into an output torque.It operates in the reverse manner of the pump. The highpressure hydraulic fluid enters through the input port. Thefluid pressure builds behind the pistons causing them tomove down the swashplate (the path of least resistance).As the piston returns up the swashplate again, the fluid isallowed to exit through the exit port. The spinning pistonsare housed in a cylinder which is connected to the outputshaft. The output torque can be applied to a mechanicalfunction.

Slider Block

Servo Piston

Servo ArmServo Valve

Cradle Bearing

Cradle Hold Down

Charge Pump

Cradle Leveler Cradle

Cradle Guide

Feed Back

6Series 90 Functional Description

90000234E

90000348Series 90 Variable Displacement Motor (MV)

Series 90 MV Cross Section

90000190ESeries 90 MF Cross Section

In the Fixed Displacement Motor the "swashplate" isfixed, so any variation in motor speed and torque must bemade by the input mechanism, i.e. the pump.

Variable Displacement Motor

The Variable Displacement Motor (MV) operates in thesame manner as the fixed motor. However, its swashplateis not fixed; it can be switched between minimum andmaximum angle to amplify torque or speed like theVariable Displacement Pump.

Piston

Roller Bearing

Output Shaft

Valve PlateLoop Flushing Valve

Cylinder BlockFixed Swashplate

End Cap

"A" "A"

Electric 2-Position Control (optional)

Piston

Roller Bearing

Valve Plate

Cradle Swashplate

Output Shaft

Cylinder Block

Minimum AngleControl Piston

Partial Section "A-A"Cradle Swashplate in Full

Displacement Position

Maximum AngleControl Piston

Cradle Swashplate

End Cap


Basic Closed Circuit90000803E

The Basic Closed Circuit

The main ports of the pump are connected by hydrauliclines to the main ports of the motor. Fluid flows, in eitherdirection, from the pump to the motor then back to thepump in this closed circuit. Either of the hydraulic linescan be under high pressure. In pumping mode theposition of the pump swashplate determines which line ishigh pressure as well as the direction of fluid flow.

Case Drain and Heat Exchanger

The pump and motor require case drain lines to removehot fluid from the system. The motor should be drainedfrom its topmost drain port to ensure the case remains fullof fluid. The motor case drain can then be connected tothe lower drain port on the pump housing and out the topmost port. A heat exchanger, with a bypass valve, isrequired to cool the case drain fluid before it returns to thereservoir.

Circuit Diagram for Series 90 PV and 90 MF90000800E

The System Circuit

Control Handle Displacement Control Valve

OrificedCheck Valve

Heat ExchangerBypass Valve

Heat Exchanger

Reservoir

Vacuum Gauge

Multi-Function ValveServo ControlCylinder

Pump SwashplateMotor Swashplate

InputShaft Output Shaft

to PumpCase

Charge Pump

Servo Pres.Relief Valve

Multi-FunctionValve

Charge PressureRelief Valve

Fixed DisplacementMotor

Servo ControlCylinderVariable

DisplacementPump

Case drain fluid

System loop (high pressure)

System loop (low pressure)

Loop Flushing Valve

Purge Relief Valve

Control fluid

Suction line

Pump Fixed Motor

Input PV MF

Case Drain Line

Output

Flow (Bi-directional)

Reservoir

8Series 90 Functional DescriptionCommon Features of Pumps and Motors

End Caps and Shafts

Series 90 pumps and motors can be supplied with avariety of end caps and shafts to allow for almost anyconfiguration. For pumps, end caps are available withsystem ports on either side ("side ports") or both ports onone side ("twin ports"). Motors have end caps with portson the face of the end cap ("axial ports") or both ports onone side ("twin ports"). See the Series 90 TechnicalInformation manuals (BLN-10029 and BLN-10030) or theSeries 90 Price Book (BLN-2-40588) for information onavailable options.

Removing the end cap will void the warranty on aSeries 90 pump or motor.

Speed Sensor90000810

Speed Sensors

An optional speed sensor can be installed on Series 90pumps and motors to provide unit speed information. Thesensor reads a magnetic ring wrapped about the unit'scylinder. See the corresponding Section to locate, installand adjust the sensor.


Charge Pump

The charge pump is necessary to supply cool fluid to thesystem, to maintain positive pressure in the main systemloop, to provide pressure to operate the control system,and to make up for internal leakage. Charge pressuremust be at its specified pressure under all conditions ofdriving and braking to prevent damage to the transmis-sion.

The charge pump is a fixed-displacement, gerotor typepump installed in the variable displacement pump anddriven off the main pump shaft. Charge pressure is limitedby a relief valve.

The standard charge pump will be satisfactory for mostapplications. However, if the charge pump sizes availablefor the given main pump size are not adequate, a gearpump may be mounted to the auxiliary mounting pad andsupply the required additional charge flow.

Charge Relief Valve

The charge relief valve on the pump serves to maintaincharge pressure at a designated level. A direct-actingpoppet valve relieves charge pressure whenever it sur-passes a certain level. This level is nominally set refer-encing case pressure at 1500 rpm. This nominal settingassumes the pump is in neutral (zero flow); in forward orreverse charge pressure will be lower. The charge reliefvalve setting is specified on the model code of the pump.

Multi-Function Valves

The multi-function valve incorporatesthe system check valve,the pressure limiter valve,the high pressure relief valve andthe bypass valve

in a replaceable cartridge.

These functions are described separately. There are twomulti-function valve cartridges in each Series 90 pump tohandle functions in either direction. See correspondingSections for adjustments and repairs.

NOTE: Some multi-function valves do not include apressure limiter valve.

PV with Charge Pump90000243

Pump Charge System90000804E

Pump Features

Multi-Function Valve90000243

CaseDrainLine Charge Relief Valve

ChargePump

SystemCheckValves

Input

Inlet Filter

Tank

PV PF

10

Series 90 Functional Description

Circuit Diagram showing PressureControl Mechanism

90000801E

Cross Section of Multi-Function Valve90000806E

Pressure Limiter and High Pressure Relief Valves

Series 90 pumps are designed with a sequenced pres-sure limiting system and high pressure relief valves.When the preset pressure is reached, the pressure limitersystem acts to rapidly destroke the pump so as to limit thesystem pressure. For unusually rapid load application,the high pressure relief valve acts to immediately limitsystem pressure by cross-porting system flow to the lowpressure side of the loop. The pressure limiter valve actsas the pilot for the high pressure relief valve spool. Thehigh pressure relief valve is sequenced to operate atapproximately 35 bar (500 psi) above the level that ini-tiates the pressure limiter valve.

Both the pressure limiter sensing valves and relief valvesare built into the multi-function valves (see above).

NOTE: For some applications, such as dual path ve-hicles, the pressure limiter function may be de-feated so that only the high pressure relief valvefunction remains.

System Check Valves

The system check valves allow pressurized flow from thecharge pump to enter the low pressure side of the loopwhenever system pressure dips below a certain level.This is needed as the pump will generally lose systempressure due to leakage and other factors. Since thepump can operate in either direction, two system checkvalves are used to direct the charge supply into the lowpressure lines. The system check valves are poppetvalves located in the multi-function valve assembly.

Bypass Valves

The bypass valves ("tow") can be operated when it isdesired to move the vehicle or mechanical function whenthe pump is not running. The valve is opened by manuallyresetting the valve position.

The bypass valves are built into the multi-function valves.

Servo Pres.Relief Valve


Multi-Function Valve


To Control

Servo Piston

Servo Piston

Port "A"

Port "B"

BypassAdjustment

High PressureRelief / checkValve Poppet

Pressure LimiterValve Poppet

BypassActuator

Pressure LimiterAdjustment Screw

Pressure LimiterLock Nut

Pressure Limiter HousingCheck Valve

Poppet

Bypass

11

Series 90 Functional DescriptionDisplacement Limiters

All Series 90 pumps are designed for optional mechanicaldisplacement (stroke) limiters. The maximum displace-ment of the pump can be limited in either direction.

The setting can be set as low as 0 in either direction.

For instructions on adjustment see corresponding Sec-tion.

Auxiliary Mounting Pads

Auxiliary mounting pads are available on all Series 90pumps. SAE A through E mounts are available (availabil-ity varies by pump size). This pad is used for mountingauxiliary hydraulic pumps and for mounting additionalSeries 90 pumps to make tandem pumps. The pads allowfor full through-torque capability.

Filtration Options

All Series 90 pumps are available with provisions foreither suction or charge pressure filtration (integral orremote mounted) to filter the fluid entering the chargecircuit.

Suction Filtration

The suction filter is placed in the circuit between thereservoir and the inlet to the charge pump. When suctionfiltration is used, a reducer fitting is placed in the chargepressure gauge port (M3). Filtration devices of this typeare provided by the user.

Charge Pressure Filtration

The pressure filter may be integrally mounted directly onthe pump or a filter may be remotely mounted for ease ofservicing.

A 125 m screen, located in the reservoir or the chargeinlet line, is recommended when using this filtrationoption.

90000244PV with Displacement Limiters

90000243PV with Suction Filtration

(No filtration device attached)

90000246PV with Integral Charge

Pump

90000247

PV with Auxillary Mounting Pad90000242

PV with Remote ChargePump

12

Series 90 Functional DescriptionPressure Override (POR) - 180 Frame Size Only

The pressure override valve (POR) modulates the controlpressure to the displacement control to maintain a pumpdisplacement which will produce a system pressure levelless than or equal to the POR setting. For unusually rapidload application, the high pressure relief valve function ofthe multifunction valves is available to also limit thepressure level.

The pressure override consists of a three-way normallyopen valve which operates in series with the pumpdisplacement control. Control supply pressure is nor-mally ported through the pressure override valve to thedisplacement control valve for controlling the pump'sdisplacement. If the system demands a pressure abovethe override setting, the POR valve will override thecontrol by reducing the control pressure supplied to thedisplacement control. As the control pressure reduces,the internal forces tending to rotate the swashplateovercome the force of the servo pistons and allow thepump's displacement to decrease.POR-Valve (180 Frame Size only)

90000802E

ShuttleValve



BypassAdjustment


PressureOverride Control Valve

To Control

Port "A"

Port "B"

13


PV with Manual Displacement Control andNeutral Start Switch

PV with Hydraulic Displacement Control

PV with Manual Displacement Control90000237

90000239

90000240

Pump Control Options

Non-Linear MDC

The non-linear manual displacement control operates inthe same manner as the regular MDC except that it isdesigned so the change in the angular position of thepump swashplate progressively increases as the controlinput shaft is rotated toward its maximum displacementposition.

Solenoid Override Valve for MDC

A solenoid override valve option (not shown here) isavailable for MDC. This safety feature will return theswashplate to zero displacement position when acti-vated. The valve may be set in either a normally open ornormally closed mode.

Neutral Start Switch (NSS)

The neutral start switch is an optional feature availablewith MDC. When connected properly with the vehicleselectrical system, the neutral start switch ensures that theprime mover can be started only when the control is in aneutral position.

Hydraulic Displacement Control (HDC)

The hydraulic displacement control uses a hydraulic inputsignal to operate a spring-centered four-way servo valve.This valve ports hydraulic pressure to either side of adual-acting servo piston. The servo piston rotates thecradle swashplate through an angular rotation of 17,thus varying the pumps displacement from full displace-ment in one direction to full displacement in the oppositedirection. The HDC is designed so the angular position ofthe pump swashplate is proportional to input pressure.

Manual Displacement Control (MDC)

The manual displacement control converts a mechanical input signal to a hydraulic signal using a spring- centered four-way servo valve. This valve ports hydraulic pressure to either side of a dual-acting servo piston. The servo piston rotatesthe cradle swashplate through an angular rotation of 17, thus varying the pumps displacement from full displacementin one direction to full displacement in the opposite direction.

The MDC is designed so the angular position of the pump swashplate is proportional to the rotation of the control inputshaft.

14


PV with 3-Position (FNR) Electric Control90000354

PV with Electric Displacement Control

Electric Displacement Control (EDC)

The electric displacement control is similar to the hydrau-lic displacement control with the input signal pressurecontrolled by a pressure control pilot (PCP) valve. ThePCP valve converts a DC electrical input signal to ahydraulic signal which operates a spring- centered four-way servo valve. This valve ports hydraulic pressure toeither side of a dual-acting servo piston. The servo pistonrotates the cradle swashplate through an angular rotationof 17, thus varying the pumps displacement from fulldisplacement in one direction to full displacement in theopposite direction. The control is designed so the angularposition of the swashplate is proportional to the EDCinput.

Automotive Control (FBA II B)

Automotive Control allows a vehicle to be driven in amanner similar to an automobile with an automatic trans-mission.

The Automotive Control includes a three-position electriccontrol to provide direction control.

3-Position (FNR) Electric Control

This control utilizes a 12 or 24 VDC electrically operatedspool valve to port pressure to either side of the pumpdisplacement control piston. Energizing one of the sole-noids will cause the pump to go to its maximum displace-ment in the corresponding direction.

All functions of the three-position (FNR) electric controlare preset at the factory.

90000241

15

Series 90 Functional DescriptionMotor Features

Motor Loop Flushing Valve and Charge ReliefValve

All Series 90 motors are designed to accommodate a loopflushing valve. The loop flushing valve is used in instal-lations which require additional fluid to be removed fromthe main hydraulic circuit because of transmission cool-ing requirements, or unusual circuits requiring additionalloop flushing to remove excessive contamination in thehigh pressure circuit.

A shuttle valve and charge relief valve are installed in themotor end cap to provide the loop flushing function. Theshuttle valve provides a circuit between the low pressureside of the closed loop and the charge relief valve in themotor end cap.

The motor charge relief valve regulates the charge pres-sure level only when there is a pressure differential in themain loop. The shuttle valve is spring centered to theclosed position so that no high pressure fluid is lost fromthe circuit when reversing pressures.

For charge relief valve adjustment see correspondingSection.

Variable Motor Displacement Limiters

All Series 90 variable motors include mechanical dis-placement (stroke) limiters. Both the maximum and mini-mum displacement of the motor can be limited.

The range of the settings is as follows:

VM550 VM570

muminiMtnemecalpsiD

mc04-91 3ni4.2-2.1 3

mc45-62 3ni3.3-6.1 3

mumixaMtnemecalpsiD %001-56 %001-56

E152200T

Loop Flushing Valve (MF)90000248

90000238E

Motor Charge Relief Valve and Loop FlushingShuttle Valve

MV Maximum Displacement Limiter(Minimum Displacement Limiters on opposite side)

90000352

Charge Relief Valve

Loop Flushing Shuttle Valve End Cap

Top of Motor

16


MV with Electric 2-Position Control

Hydraulic 2-Position Control

This control utilizes a hydraulically operated three-wayhydraulic valve to port system pressure to either of themotor displacement control pistons. The motor is nor-mally held at its maximum displacement. Supplying pilothydraulic pressure to the valve will cause the motor to goto its minimum displacement.

Electric 2-Position Control

This control utilizes an electric solenoid operated three-way hydraulic valve to port system pressure to either ofthe motor displacement control pistons. The motor isnormally held at its maximum displacement. Energizingthe solenoid will cause the motor to go to its minimumdisplacement.

Variable Motor Controls

MV with Hydraulic 2-Position Control

90000351

90000350

17

Series 90 Technical Specifications

PV with Charge Pump and ManualDisplacement Control

MF

MV with Electrohydraulic 2-PositionControl

M2B

L1

M1A

L2 M3

M1

M2

A

B

M4M5

L2SL1

M3X5

M3

Vgmax

M2BL1

M1A

L2

Technical Specifications

General Specifications

Design

Variable Pumps and Motors: Axial piston pump of vari-able displacement, cradle swashplate design.

Fixed Motors: Axial piston motor with fixed displacement,fixed swashplate design.

Type of Mounting (per SAE J744)

SAE flange, Size "B", 2 bolts,SAE flange, Size "C and E", 4 bolts.

Cartridge flange, 2 bolts (for motor only).

Port Connections(for details see chapter "Pressure Measurement")

Main pressure ports: SAE flange, Code 62,Remaining ports: SAE straight thread O-ring boss.

Direction of Rotation

Clockwise or counterclockwise (motors are bi-directional)

Recommended Installation Position

Pump installation recommended with control position onthe top or side. Consult SAUER-SUNDSTRAND for non-conformance guidelines. The housing must always befilled with hydraulic fluid.

Circuit Diagrams

900008119000081290000813

18


Hydraulic FluidRefer to SAUER-SUNDSTRAND BLN 9887 or SDF (IdNo. 697581). Also refer to publication ATI-E 9101 forinformation relating to biogradable fluids.

Hydraulic Parameters

CleanlinessRefer to SAUER-SUNDSTRAND Publications BLN 9887or SDF (NO. 697581) and ATI-E 9201.

Refer to Series 90 technical information for definitions.

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E010200T

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E700200T

19


Fixed and Variable Displacement Motors

Variable Displacement Pumps

Size Specific Data

Refer to Series 90 technical information for definitions.

noisnemiD VP030 VP240 VP550 VP570 VP001 VP031 VP081 VP052

tnemecalpsiD)mumixam(

mc 3

ni 30338.1

2465.2

5553.3

5775.4

00101.6

03139.7

08189.01

05252.51

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20

Series 90 Pressure MeasurementPressure Measurement

Required Tools

The service procedures described in this manual forSeries 90 pumps and motors can be performed usingcommon mechanic's tools. Special tools, if required areshown.

Port Locations and Pressure Gauge Installation

Pressure gauges should be calibrated frequently to en-sure accuracy. Snubbers are recommended to protectpressure gauges.

The following sections list the ports for each type ofhydraulic unit. The recommended pressure gauge andfitting are also specified.

Variable Pump

troP noitcnuFeziSeguaG

dnagnittiF

1M erusserPmetsyS"A"troP

isp00001rorab0001gnir-O81-61/9

2M erusserPmetsyS"B"troP

isp00001rorab0001gnittifgnir-O81-61/9

3M)6M( erusserPegrahC


4M5M erusserPovreS


E952200T

Outline drawings showing port locations follow the tablesbelow.


dnagnittiF

1L2L

erusserPesaCisp001rorab01

030240 gnir-O41-8/7

550570001

gnir-O21-61/1-1

031 gnir-O21-61/5-1081052 gnir-O21-8/5-1

1X2X

CDE/CDHerusserPlortnoC


rognir-O81-61/9

3X lortnoClanretxEerusserP


S telnIpmuPegrahC otnieeT,eguaGmuucaVeniLtelnI

030240 gnir-O21-61/1-1

550570 gnir-O21-61/5-1

001031081

gnir-O21-8/5-1

052 tilpS-EAS2/1-1egnalF

E062200T

21

Series 90 Pressure Measurement

PV with Side Port End Cap and Manual Displacement Control

90000814E

90000815E90000816E

Servo / DisplacementCylinder Pressure

Gauge Port M5

Servo / DisplacementCylinder Pressure

Gauge Port M4Case Drain

Port L1

Top View

System PressurePort B

System PressureGauge Port M2


System PressurePort A

Case Drain Port L2

Left Side View


Carge PumpInlet Port S

Charge Inlet Pressure

External Control PressureSupply Port X3

Charge PressureGauge Port M3

Right Side View

Speed Sensor

22


PV with Side Port End Cap and Remote Pressure Filtration PV with Side Port End Cap and Integral Pressure Filtration

PV with Twin Port End Cap and Manual Displacement Control

90000817E90000818E

90000819E90000820E



Case Drain Port L2

Left Side View


Charge Pump InletPort S

System PressurePort A

Servo / DisplacementCylinder PressureGauge Port M5

Servo / DisplacementCylinder PressureGauge Port M4Case Drain

Port L1

Top View

Charge PressureGauge Port M3(after the filter)

Port E(from filter)

Port D(to filter)

Rear View

Charge PressureGauge Port M3(after the filter)

Charge PressureGauge Port M6(before the filter)

Rear View

23


Case Drain Port L1

Case Drain Port L2System Pressure Port B

Left Side View

Left Side View

Rear View

Rear View

System Pressure Port A


Case Drain Port L1

Case Drain Port L2System Pressure Port BSystem Pressure Port A

Speed Sensor

Speed Sensor






Fixed Motor

MF with SAE Flange

90000821E

MF with Cartridge Flange


dnagnittiF

1M erusserPmetsyS"A"troP


2M erusserPmetsyS"B"troP


3MerusserPegrahC isp0001rorab05 gnir-O81-61/9

E162200T


dnagnittiF

1L2L

)erusserPesaCisp005rorab01

030240550

gnir-O41-8/7

570001031

gnir-O21-61/1-1

E262200T

24


Displacement ControlCylinder PressureGauge Port M4Min. Displacement

Displacement ControlCylinder PressureGauge Port M5Max. Displacement(Newer Production)

Displacement ControlCylinder PressureGauge Port M5Max. Displacement(Earlier Production -Not available as gaugeport with servo orifices)


Control PressurePort X1

(Hydraulic 2-Position Control)


Case Drain Port L1

Case Drain Port L2

System Pressure Port A

System Pressure Port B

Left Side View

Right Side View

Speed Sensor

charge PressureGauge Port M3(Same position as in MF)

Variable Motor

MV with Cartridge Flange and Hydraulic 2-Position Control (SAE Flange Version Similar)

90000823E


dnagnittiF

4MredbnilyClortnoCmuminiM"erusserP

"tnemecalpsiDisp00001rorab0001

gnir-O02-61/7

5MredbnilyClortnoCmumixaM"erusserP

"tnemecalpsiDisp00001rorab0001

gnir-O02-61/7

1L2L erusserPesaC

isp005rorab01gnir-O21-61/1-1

E462200T


dnagnittiF

1M erusserpmetsyS"A"troP


2M erusserpmetsyS"B"troP


3MerusserPegrahC isp0001rorab05 gnir-O81-61/9

E362200T

MV with SAE Flange (Cartridge Flange Version Similar)

25

Series 90 Initial Start-Up ProcedureInitial Start-Up Procedure

The following start-up procedure should always be fol-lowed when starting-up a new Series 90 installation orwhen restarting an installation in which either the pump ormotor had been removed.

connections for EDC) be disconnected at the pumpcontrol until after initial start-up. This will ensure that thepump remains in its neutral position.

Prior to installing the pump and/or motor, inspect the unitsfor damage incurred during shipping and handling. Makecertain all system components (reservoir, hoses, valves,fittings, heat exchanger, etc.) are clean prior to filling withfluid.

Fill the reservoir with recommended hydraulic fluid. Thisfluid should be passed through a 10 micron (nominal, nobypass) filter prior to entering the reservoir. The use ofcontaminated fluid will cause damage to the components,which may result in unexpected vehicle/machine move-ment. See the publications BLN-9887 and SDF 697581for further related information.

The inlet line leading from the reservoir to the pump mustbe filled prior to start-up. Check inlet line for properlytightened fittings and make sure it is free of restrictionsand air leaks.

Be certain to fill the pump and/or motor housing withclean hydraulic fluid prior to start up.

Fill the housing by pouring filtered oil into the upper casedrain port.

Install a 50 bar (or 1000 psi) pressure gauge in the chargepressure gauge port to monitor the charge pressureduring start-up.

It is recommended that the external control input signal(linkage for MDC, hydraulic lines for HDC, or electrical

Jog or slowly rotate prime mover until charge pressurestarts to rise. Start the prime mover and run at the lowestpossible RPM until charge pressure has been estab-lished. Excess air may be bled from the high pressurelines through the high pressure system gauge port.

Once charge pressure has been established, increasespeed to normal operating RPM. Charge pressure shouldbe as indicated in the pump model code. If chargepressure is inadequate, shut down and determine causefor improper pressure. Refer to Troubleshooting.

WARNINGThe following procedure may require the vehicle/machine to be disabled (wheels raised off the ground,work function disconnected, etc.) while performingthe procedure in order to prevent injury to thetechnician and bystanders. Take necessary safetyprecautions before moving the vehicle/machine.

S000 007E

WARNINGDo not start prime mover unless pump is in neutralposition (0 swashplate angle). Take precautions toprevent machine movement in case pump is actuatedduring initial start up.

S000 008E

Shut down the prime mover and connect the externalcontrol input signal. Also reconnect the machine functionif disconnected earlier. Start the prime mover, checkingto be certain the pump remains in neutral. With the primemover at normal operating speed, slowly check for for-ward and reverse machine operation.

Charge pressure may slightly decrease during forward orreverse operation. Continue to cycle slowly betweenforward and reverse for at least five minutes.

Shut down prime mover, remove gauges, and plug ports.Check reservoir level and add filtered fluid if needed.

The transmission is now ready for operation.

WARNINGTake necessary precautions that the motor shaftremains stationary during the adjustmentprocedure.

S000 010E

26

Series 90 Fluid and Filter MaintenanceFluid and Filter Maintenance

To ensure optimum service life of Series 90 products,regular maintenance of the fluid and filter must be per-formed. Contaminated fluid is the main cause of unitfailure. Care should be taken to maintain fluid cleanlinesswhile performing any service procedure.

Check the reservoir daily for proper fluid level, the pres-ence of water (noted by a cloudy to milky appearance, orfree water in bottom of reservoir), and rancid fluid odor(indicating excessive heat). If either of these conditionsoccur, change the fluid and filter immediately.

It is recommended that the fluid and filter be changedper the vehicle/machine manufacturers recommenda-tions or at the following intervals:

First change

500 operating hours after start up

second and subsequent changes

every 2000 operating hours or once a year.

This recommendation applies for the most applications.High temperatures and pressures will result in acceler-ated fluid aging and an earlier fluid change may berequired. At lower fluid loads longer change intervalls arepossible. Therefore we suggest to check the fluid with themanufacturer for suitability. This should be done at latesthalf way between fluid changes.

It may be necessary to change the fluid more frequentlythan the above intervals if the fluid becomes contami-nated with foreign matter (dirt, water, grease, etc.) or ifthe fluid has been subjected to temperature levels greaterthan the recommended maximum. Never reuse fluid.

The filter should be changed whenever the fluid is changedor whenever the filter indicator shows that it is necessaryto change the filter.

P000 797E

P000 798E

Suction Filtration Schematic

Charge Pressure Filtration Schematic(Partial flow)

Charge pump

Filter

Hydraulic fluid reservoir

AdjustableCharge pressure relief valve

To pump case

to low pressureside andcontrol

Mano-Vacuummeter

To pump case

Charge pump

Hydraulic fluid reservoir

Filter

to low pressureside andcontrol

Screen

AdjustableCharge pressure relief valve

dnaleveLssenilnaelC x oitaR-ssenilnaelcdiulfderiuqeR

level31/81ssalC6044OSI

dednemmoceR x

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dednemmoceR x

oitar-erusserpegrahcrof

noitartlif

02-51(57=

01 )01

telnidednemmoceRegrahcrofezisneercs

noitartliferusserp001 521-m m

E700200T

27

Series 90 ToubleshootingTroubleshooting

This section provides general steps to follow if certain undesirable system conditions are observed. Follow the steps ina section until the problem is solved. Some of the items will be system specific. For areas covered in this manual, a sectionis referenced. Always observe the safety precautions listed in the section "Introduction" and related to yourspecific equipment.

"NEUTRAL" Difficult or Impossible to Find

Check Description Action

1. Input to pump control.

2. Pump displacement control.

Input to control module is operatingimproperly.

Control linkages are not secure, controlorifices are blocked, etc.

Check control input and repair or re-place as necessary.

Adjust, repair, or replace control mod-ule as necessary.

System Operating Hot


1. Oil level in reservoir.

2. Heat exchanger.

3. Charge pressure.

4. Charge pump inlet vacuum.

5. System relief pressure settings.

6. For internal leakage in motor.

7. System pressure.

Insufficient hydraulic fluid will not meetcooling demands of system.

Heat exchanger not sufficiently coolingthe system.

Low charge pressure will overwork sys-tem.

High inlet vacuum will overwork sys-tem. A dirty filter will increase the inletvacuum. Inadequate line size will re-strict flow.

If the system relief settings are too low,the relief valves will be overworked.

Leakage will reduce low side systempressure and overwork the system.

High system pressure will overheatsystem.

Fill reservoir to proper level.

Check air flow and input air tempera-ture for heat exchanger. Clean, repairor replace heat exchanger.

Measure charge pressure. Inspect andadjust or replace charge relief valve. Orrepair leaky charge pump.

Check charge inlet vacuum. If high,inspect inlet filter and replace as neces-sary. Check for adequate line size,length or other restrictions.

Verify settings of pressure limiters andhigh pressure relief valves and adjustor replace multi-function valves as nec-essary.

Monitor motor case flow without loopflushing in the circuit (use defeat spool).If flow is excessive, replace motor.

Measure system pressure. If pressureis high reduce loads.

If the above actions do not remedy the problemcontact a SAUER-SUNDSTRAND Authorized Service Center.


28

Series 90 ToubleshootingTransmission Operates Normally in One Direction Only




3. Interchange system pressure limit-ers, high pressure relief valves, andsystem check valves.

4. Charge pressure.



Interchanging the multi-function valveswill show if the problem is related to thevalve functions contained in the multi-function valves.

If charge pressure decays in one direc-tion the loop flushing valve may besticking in one direction.


Repair or replace control module asnecessary.

Interchange multi-function valves. If theproblem changes direction, repair orreplace the valve on the side that doesnot operate.

Measure charge pressure in forwardand reverse. If pressure decays in onedirection, inspect and repair the motorloop flushing valve.

System Will Not Operate in Either Direction





4. Ensure bypass valve(s) are closed.

5. Charge pressure with pump in neu-tral.

6. Charge pressure with pump instroke.

7. Pump charge relief valve.

8. Charge pump inlet filter.

9. Charge pump.

Insufficient hydraulic fluid to supplysystem loop.



If bypass valve(s) is open, the systemloop will be depressurized.

Low charge pressure insufficient to re-charge system loop.

Low charge pressure with the pump instroke indicates a motor charge reliefvalve or system pressure relief valvemay be improperly set.

A pump charge relief valve that is leakyor set too low will depressurize thesystem.

A clogged filter will undersupply systemloop.

A malfunctioning charge pump will pro-vide insufficient charge flow.




Close bypass valves. Replace multi-function valve if defective.

Measure charge pressure with the pumpin neutral. If pressure is low, go to step6; otherwise continue with step 5.

Measure charge pressure with pump instroke. If pressure is low, adjust orreplace motor charge relief valve, oth-erwise go to step 9.

Adjust or replace pump charge reliefvalve as necessary.

Inspect filter and replace if necessary.

Repair or replace the charge pump. IfOK go to last step.


29

Series 90 Toubleshooting

Low Motor Output Torque


1. System pressure at motor.

2. Variable motor stuck at minimumdisplacement.

3. For internal leakage.

Low system pressure at the motor willreduce torque.

Minimum motor displacement yields lowoutput torque.

Internal leakage will reduce systempressure.

Measure system pressure at motor. Ifpressure limiter setting is low, increasesetting.

Check control supply pressure or re-pair displacement control. Check mo-tor control orifices.

Check for leakage in O-rings, gaskets,and other fittings. Repair unit as re-quired, or replace leaky unit.

Improper Motor Output Speed



2. Pump output flow.

3. Variable motor displacement con-trol.

4. For internal leakage.

Insufficient hydraulic fluid will reducemotor speed.

Incorrect outflow will affect outputspeed. Incorrect output flow indicatesthe swashplate is out of position.

If variable motor displacement controlis not functioning correctly, variablemotor swashplate may be in wrongposition.


Fill oil to proper level.

Measure pump output and check forproper pump speed and see that thepump is in full stroke.

See if variable motor displacement con-trol is responding. If not, repair or re-place control.

Check for leakage in O-rings, gaskets,and other fittings. Repair unit as re-quired, or replace leaky unit.


11. System pressure.

12. System multi-function valves.


Low system pressure will not providepower necessary to move load.

Defective multi-function valves willcause system pressure to be low.


Measure system pressure. Continuewith next step.

Repair or replace multi-function valve(s).




30

Series 90 Toubleshooting

System Response is Sluggish



2. Multi-function valves pressure set-tings.

3. Pump inlet vacuum.

4. Prime mover speed.

5. Charge and control pressures.

6. System internal leakage.

Insufficient hydraulic fluid will reduceoutput pressure.

Incorrect pressure settings will affectsystem reaction time.

High pump inlet vacuum will reducesystem pressure.

Low engine speed will reduce systemperformance.

Incorrect charge or control pressureswill affect system performance.



Adjust or replace multi-function valves.

Measure charge inlet vacuum. If highreplace inlet filter.

Adjust engine speed.

Measure charge and control pressuresand correct if necessary.

Check for leakage in O-rings, gaskets,and other fittings.

Excessive Noise and/or Vibration

Check Description Action1. Oil in reservoir.

2. Air in system.

3. Pump inlet vacuum.

4. Shaft couplings.

5. Shaft alignment.

Insufficient hydraulic fluid will lead tocavitation.

Air bubbles will lead to cavitation.

High inlet vacuum will create noise. Adirty filter will increase the inlet vacuum.

A loose shaft coupling will cause exces-sive noise.

Unaligned shafts will create excessivefrictional noise.


Look for foam in reservoir. Check forleaks on inlet side of system loop. After-wards, let reservoir settle until bubblesare gone. Run system at low speed tomove system fluid to reservoir. Repeat.

Inspect and replace filter as necessary.Check for proper suction line size.

Replace loose shaft coupling in chargepump or replace pump or motor.

Align shafts.



31

Series 90 Inspections and AdjustmentsInspections and AdjustmentsThis section offers instruction on how to perform inspections and adjustments on pump and motor components. Readthrough the entire related section before beginning a service activity. Refer to the corresponding section for location ofgauge ports and suggested gauge size.

Pump Adjustments

Charge Pressure Gauge Port (Reducer fitting shown - iffiltration device attached)

90000243

90L055 EA 1 N6 S 3 C6 C 03HNN 35 35 24

Model Code on Unit Name Plate (24 bar)

NominalCharge Pressure

Charge Pressure Relief Valve Adjustment

The following procedure explains how to check and adjustthe charge pressure relief valve.

* This is the actual charge pressure port gauge reading minusthe case pressure port gauge reading.

Note: These pressures assume a pump speed of1450 - 1500 rpm. At higher pump input speeds(with higher charge flows) the charge pressurewill rise over the rated setting.


S000 007E

1. To measure pump charge pressure, install a pres-sure gauge in the pump charge pressure gauge port(M3). Also install a gauge to measure case pressure(tee into L1 or L2 or use servo gauge port). Operatethe system with the pump in neutral (zero displace-ment) when measuring pump charge pressure.

2. The table shows the acceptable pump charge pres-sure range for some nominal charge relief valvesettings (see sample model code at right). Thesepressures assume 1500 pump rpm and a reservoirtemperature of 50C (120F ), and are referenced tocase pressure (see footnote on next page). Smallerdisplacement charge pumps will produce chargepressure readings in the lower portion of the range,while larger displacement charge pumps will producereadings in the higher portion of the range.

edoCledoM *erusserPegrahCderusaeM

02 rab7.12sib1.81 )isp513ot262(42 rab9.62sib0.22 )isp093ot913(82 rab7.03sib8.52 )isp544ot473(

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.gnidaereguagtroperusserpesac

32

Series 90 Inspections and Adjustments

Shim Adjustable ChargePressure Relief Valve

(Pump)

Screw Adjustable ChargePressure Relief Valve

(Pump)

90000262 90000264

3. Earlier production Series 90 pumps are equippedwith a shim adjustable charge pressure relief valve.Shim kits are available from SAUER-SUNDSTRAND.Adjustment of charge pressure is accomplished byremoving the plug [1 inch Hex] and changing the shimthickness behind the spring. The plug for this type ofcharge relief valve should be torqued to 68 Nm(50 lbfft).

Later production Series 90 pumps are equipped withan external screw adjustable charge pressure reliefvalve. Adjustment of the charge pressure is accom-plished by loosening the lock nut -

eziSemarF eziShcnerW001-030 hcni61/1-1052-031 hcni8/5-1

E762200T

and turning the adjustment plug with a large screw-driver or a 1/2 inch hex wrench.

Clockwise rotation of the plug increases the setting,and counterclockwise rotation decreases the setting(at a rate of approximately 3.9 bar (50 psi) per turn).The lock nut for this type of charge relief valve shouldbe torqued to 52 Nm (39 lbfft).

4. Once the desired charge pressure setting is achieved,remove the gauges.

33

Series 90 Inspections and AdjustmentsMulti-Function Valve Pressure Adjustment

Adjustment of the pressure limiter setting and the highpressure relief valve setting is accomplished simulta-neously. The latter is automatically set approximately35 bar (500 psi) above the former.

In order to adjust the pressure limiter setting, the motoroutput shaft must be locked so it does not rotate. Thismay be accomplished by locking the vehicles brakes orrigidly fixing the work function so it cannot rotate.

1. Install two 1000 bar (or 10 000 psi) pressure gaugesin the high pressure gauge ports (M1 and M2). Installa 50 bar (or 1000 psi) pressure gauge in the pumpcharge pressure gauge port (M3).

2. Start the prime mover and operate at normal speed.

3. Loosen locking nut.

eziSemarF eziShcnerWylrae

001-240 mm01

rewen001-030 mm91

031ylrae mm31052-031 mm42

E862200T

4. Insert a internal hex wrench into the pressure adjust-ing screw.

eziSemarF eziShcnerWxeHlanretnIylrae

001-240 mm3

rewen001-030 mm5

031ylrae mm4052-031 mm8

E962200T

Note: A plastic dust plug is installed in the adjustingscrew on 030 and late 042 through 250 units.

90000258

Multi-Function Valves on PV

Loosen Pressure Adjusting Screw Lock Nut90000259

WARNINGTake necessary precautions that the motor shaftremains stationary during the adjustment procedure.

S000 010E

34


Rotate Pressure Adjusting Screw90000260

Tighten Lock Nut90000261

90L055 EA 1 N6 S 3 C6 C 03HNN 35 35 24

Pressure Limiter SettingPorts A and B (differentialpressure in 10s of bars,

e.g. 35 = 350 bar)

5. The factory preset pressure limiter setting is shownon the model code as at right. It is referenced tocharge pressure, so the pressure limiter setting is thedifference between the high and low pressure sidesof the system loop. Activate or move the control inputso that pressure increases in the high pressure sideof the closed circuit to the pressure limiter pressuresetting. The pressure limiter setting is reached whenthe pressure stops increasing and remains steady ata given pressure level (as shown on the gauges).

6. Return the pump to its neutral (zero flow) positionand adjust the pressure limiter setting by rotating thepressure adjusting screw with the internal hex wrench.

Clockwise rotation of the pressure adjustment screwwill increase the pressure setting, and counterclock-wise rotation will decrease the pressure setting. Eachcomplete rotation of the pressure adjusting screwchanges the pressure as shown in the following table.

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ylrae001-240 veRrep)isp7511(rab08

rewen001-030 rab09 veRrep)isp0031(052-031 rab08 veRrep)isp7511(

E072200T

7. To verify the actual pressure setting, actuate or movethe control input so that the pump again developspressure in the high pressure circuit to the newlyadjusted pressure limiter pressure setting, and readthe high pressure gauge. Then allow the pump toreturn to its neutral position. The pressure in thehigh pressure circuit should return to the chargepressure setting.

8. While holding the pressure adjusting screw station-ary, tighten the pressure adjusting screw lock.

eziSemarF euqroTylrae

001-240 )nifbl62(mN3rewen

001-030 mN02 )tffbl51(052-031 03(mN04 )tffbl

E172200T

Do not overtorque.

9. Shut down the prime mover, remove the gauges andinstall the gauge port plugs. Replace the plastic dustplugs (if used).

The same procedure is used for setting the pressure limitof the other multi-function valve, but the control inputsignal must be activated or moved in the opposite direc-tion so that high pressure develops in the opposite sideof the closed circuit.

35


Loosening and Rotating Bypass Hex on Multi-FunctionValve

90000266

Multi-Function Valve with Bypass Function Engaged90000827E

Engaging the Bypass Function

The bypass function is performed by the multi-functionvalve cartridges. The prime mover should be shut downwhen opening or closing the bypass valves.

The bypass valves on both of the multi-function valvesmust be opened to engaged the bypass function.

1. Using a

eziSemarF eziShcnerWrewen

001-030 hcni61/1-1

052-031 hcni8/3-1E272200T

wrench on the middle sized hex of the multi-functionvalve cartridge, and a

eziSemarF eziShcnerWrewen

001-030 hcni4/1-1

052-031 hcni8/5-1E372200T

wrench on the large hex to prevent rotation of thecartridge assembly, rotate the middle hex threerevolutions counterclockwise to open the bypassvalve. Do not rotate more than 3-1/2 revolutions,as additional rotation will permit external leak-age.

2. For units with an MDC-type control, prior to movingthe vehicle or otherwise causing the motor shaft toturn, move the control handle of the manual displace-ment control on the pump to the maximum fullforward position. Hold the handle in this positionduring bypass valve operation.

Caution"Tow" at extremely low speeds and for shortdistances only.

S000 011E

3. To close the bypass valve, rotate the middle hexclockwise until it is seated. Then torque the middlehex.

eziSemarF euqroTrewen

001-030 )tffbl03(mN14052-031 )tffbl57(mN001

E472200T

BypassActuator

Opening Bypass Valveallows flow to circuit

through Multi-Function Valves

36


Pressure Override Valve for 180 Frame Size90000828E

Pressure Override (POR) Valve PressureAdjustment (Option for 180 Frame Size)

The Pressure Override Valve is explained in the corre-sponding section.

1. Install two 1000 bar (or 10 000 psi) pressure gaugesin the high pressure gauge ports (M1 and M2). Installa 50 bar (or 1000 psi) pressure gauge in the pumpcharge pressure gauge port (M3).

2. Start the prime mover and operate at normal speed.

3. With the pump operating at approximately 20% dis-placement, load the work function and note thepressure as the POR valve operates (pump displace-ment reduces to zero).

4. Adjustment of the pressure override setting is madeby loosening the lock nut with a 9/16 inch hex wrenchand turning the adjustment screw with a 3/16 inchinternal hex wrench. The POR setting should be atleast 50 bar (750 psi) below the high pressure reliefvalve setting of the multi-function valves for properoperation.

5. Following the adjustment, torque the lock nut to43 Nm (32 lbfft).

6. Shut down the prime mover and remove the gaugesand install the gauge port plugs.

Right Side View

Pressure Override Valve

Lock Nut

Adjusting Screw

37


Loosen Displacement Limiter Lock Nut90000267

90000268Rotate Adjusting Screw

Tighten Lock Nut90000269

Displacement Limiter Adjustment

The maximum displacement can be limited in eitherdirection.

1. Loosen the seal lock nut retaining the displacementlimiter adjusting screw.

eziSemarF eziShcnerW001-030 mm31

031 mm71052-081 mm91

E572200T

2. Rotate the adjusting screw.eziSemarF eziShcnerWxeHlanretnI

001-030 mm4031 mm5

052-081 mm6E672200T

Rotating the adjusting screw clockwise will decreasethe maximum displacement of the pump while rotat-ing the adjusting screw counterclockwise will in-crease the maximum displacement.

3. After establishing the desired maximum displace-ment setting, tighten the lock nut on the adjustingscrew as follows.

eziSemarF euqroT001-030 )tffbl81(mN42

031 mN84 )tffbl53(052-081 )tffbl29(mN521

E872200T

4. One turn of the adjusting screw will change themaximum displacement approximately as follows.

eziSemarF foveRreppsiDniegnahCxorppAwercSgnitsujdA

030 mc8.2 3 ni71.0(veR/ 3 )veR/240 mc5.3 3 ni12.0(veR/ 3 )veR/550 mc2.4 3 ni62.0(veR/ 3 )veR/570 mc1.5 3 ni13.0(veR/ 3 )veR/001 mc2.6 3 ni83.0(veR/ 3 )veR/031 mc8.8 3 ni35.0(veR/ 3 )veR/081 mc5.21 3 ni67.0(veR/ 3 )veR/052 mc3.71 3 ni60.1(veR/ 3 )veR/

E772200T

CautionCare should be taken in adjusting displacementlimiters to avoid undesirable flow or speed conditions.The seal lock nut must be retorqued after everyadjustment to prevent an unexpected change inoperating conditions and to prevent external leakageduring unit operation.

S000 012E

38


Variable Displacement Pump with Standard ManualDisplacement Control

90000237

Pump Control Adjustments

Standard Manual Displacement Control (MDC)Adjustment

There are no adjustable elements in the manual dis-placement control. The control spool is held in its neutralposition by centering springs and washers on each end ofthe spool. Since there is no centering spring on the controlinput shaft, the shaft will automatically assume the appro-priate position when the control is installed on the pump.

39


90000357Rotate Neutral Adjusting

Screw

90000358Tighten Neutral Adjusting

Screw Lock Nut

Variable Displacement Pump with Non-Linear ManualDisplacement Control

90000829

Non-Linear Manual Displacement Control(MDC)

A centering spring, located on the control input shaft,locates the control shaft in its neutral position. A biasspring on the control spool maintains a force on the spooland the control linkage to eliminate looseness (free-play) in the linkage.

The neutral adjustment is the only adjustment that canbe made on the nonlinear manual displacement control.All other functions are preset at the factory.

This adjustment must be made on a test stand or on thevehicle/machine with the prime mover operating.

1. Install two 50 bar (or 1000 psi) gauges in each of thedisplacement control cylinder gauge ports (M4 andM5). Disconnect the external control linkage from thecontrol handle and make certain the control shaft isin its neutral position. Start the prime mover andoperate at normal speed.

2. Loosen the lock nut on the neutral adjusting screwwith a 13 mm hex wrench.

3. Using a 4 mm internal hex wrench, rotate the neutraladjusting screw clockwise until the pressure increaseson one of the pressure gauges. Note the angularposition of the wrench.

4. Rotate the adjusting screw counterclockwise until thepressure increases by an equal amount on the othergauge. Note the angular position of the wrench.

5. Rotate the adjusting screw clockwise half the dis-tance between the locations noted above. The gaugesshould read the same pressure (case pressure),indicating that the control is in its neutral position.

6. Hold the adjusting screw stationary and tighten thelock nut to 13.5 Nm (10 lbfft). Do not overtorquethe nut.

7. Once the neutral position is set, stop the primemover, remove the gauges, and install the gaugeport plugs. Reconnect the external control linkage.


S000 007E

40


Components of the Standard Manual Displacement Controlwith Neutral Start Switch

90000830E

MDC Neutral Start Switch (NSS) Adjustments

The neutral start switch (NSS) provides a means toprevent the system prime mover from starting while thepump control handle and control input shaft are in aposition which would command the pump to go in-stroke in either the forward or reverse direction.

When the contro

manual de serviços sauer série 90

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