TecBrakeP.O. Box 27822Houston, Texas 77227

InstallationManual

Model T765A & T760AEngine BrakesFor Detroit Diesel 12.7 L. & 11.1LSeries 60 ® Engines

Engine Brakes

INSTALLATION MANUAL

TECBRAKE T765A AND T760A ENGINE BRAKEFOR DETROIT DIESEL SERIES 60® ENGINES.

The TecBrake T765A engine brake may be installed onpopular versions of the Detroit Diesel Series 60® 12.7Lengines. TecBrake Model T760A engine brake may beinstalled on Detroit Diesel Series 60® 11.1L engines andDetroit Diesel Series 60® 12.7 Pre-1991 engines. It shouldonly be installed on engines whose model numbers areincluded in the Application Chart.

All Series 60 engines S/N 06R0004455 and higher areengine brake ready. TecBrake engine brake installationon engines with lower serial number is not approved.

SECTION 1- INTRODUCTION

NOTICEThe TecBrake Engine Brake is designed as a devicefor slowing a vehicle, not stopping it. It is to be usedin conjunction with, but not a substitute for thevehicle’s service brakes. The service brakes mustbe in good operating condition and used to bringthe vehicle to a complete stop.

Material Required

The TecBrake kit includes all of the parts required tomake an installation on the most common engineconfigurations.

Prior to installation, determine the engine model to verifythat the engine brake being installed is correct for theengine. The engine model number can be found on theoption labels located on the valve cover or stamped onthe cylinder block below the intake manifold. Alsodetermine whether the engine is a DDECII or DDECIII.Depending on engine control, a different control group isrequired. Refer to the Application Chart, which list all enginemodel numbers on which the T765A and T760A enginebrake may be installed.

Figure 1-1

APPLICATION CHARTENGINE CONTROL TECBRAKE LASHMODEL TYPE MODEL SETTING6067GU40 DDECII T760A 0.020” (0.50mm)6067WU40 DDECII T760A 0.026” (0.66mm)6067WU60 DDECII T760A 0.026” (0.66mm)6067WK60 DDECIII T760A 0.026” (0.66mm)6067SK60 DDECIII T760A 0.026” (0.66mm)6067GU28 DDECII T765A 0.026” (0.66mm)6067GU60 DDECII T765A 0.026” (0.66mm)6067GU91 DDECII T765A 0.026” (0.66mm)6067GK28 DDECIII T765A 0.026” (0.66mm)6067GK60 DDECIII T765A 0.026” (0.66mm)

Special Tools

The following special tools are required for installation:1. 18mm 6/12 point socket2. Feeler gauge 0.026" / Feeler gauge 0.020"

Recommended Torque ValuesEngine Brake Hold-down bolts - 100 lbft (136 N*m)Slave Piston Adj. Screw Nuts - 25 lbft (35 N*m)Valve Cover capscrews - 9 lbft (12N*m)Bridge Adjusting screw hex nut- 35 lbft (47N*m)

SECTION 2- ENGINE PREPARATION

Figure 2-1

1. Thoroughly clean engine before beginning installation.Remove valve cover and gasket. If engine is equipped withan aluminum two-piece valve cover, remove only the uppervalve cover for brake installation.

Figure 2-2

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2. Install the thru head harness prior brake housingsinstallation. Different wire harness is used for DDECIIand DDECIII applications.

Figure 2-3

3. Remove the mounting flange cover for the electronicinjector harness. Flange is located on the rear of the enginhead. Remove two plastic plugs from spare holes in thegrommet.

Figure 2-4

4. Instert the yellow wire and the white wire from theharness, through the spare holes in the grommet. Insertthe wires from outside in.

Figure 2-5

5. Lay the harness along the side of injector wire harness.Locate the terminals between cylinders 5 and 6.

Figure 2-6

6. Insert the wires from the harness in the injector harnessconduit on the outside of the head.Replace the harnessmounting flange. Use the supplied split conduit to cover theharness wires.

Figure 2-7

7. Use the loose connector supplied on engine harness(solenoid harness). Insert the white wire from thru headharness into connector cavity No. 1, also insert the yellowwire in cavity No. 2.

Figure 2-8

8. Insert the wedge lock on the connector as shown.

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Figure 2-9

9. Connect the engine harness (solenoid harness) tothe thru head harness. Verify that the yellow wires fromengine harness connect to yellow wire from thru headharness. The wire colors must match each other on bothends of the connector to ensure proper engine brakesequencing.

Figure 2-10

10. Check injector electrical terminals. On older engines,terminals should be bent 90º upwards to provide clearancefor engine brake housings. Newer engine models requireno modifications.

Figure 2-11

11. Secure the undercover harnesses along the side theinjector wire harness. Use supplied plastic ties.

SECTION 3- BRAKE HOUSING INSTALLATION

Figure 3-1

1. Remove and discard the three camshaft bearing capbolts in locations 2,4 and 6 on the intake manifold side.Locations indicated by arrows.

CAUTIONOil from bolt bores should be removed to preventcylinder head to crack when tightening the bolts. Blowout the oil from the bolt holes. Cover the holes withtowels to reduce oil spilling. Wear eye protection toprevent personal injuries.

Figure 3-2

2. Place the two spacer bars on the exhaust manifold sideof the cylinder head. Ensure that "OUT" marking areadjacent to each other, and facing outwards.

3. Position the entire wiring harness to keep it frominterference by rocker levers. The brake harness connectorshould be positioned between cylinder 5 and 6. Use plasticties to locate it to the side of spacer bar. Make sure thatsolenoid attaching wires are positioned in direction of thethree camshaft bearing cap bolts previously removed inlocations 2,4 and 6.

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Figure 3-3

Figure 3-5

5. Install the hardened washers on each of the nineTecBrake hex head hold-down bolts.

Figure 3-4

4. Place the three engine brake housings over the rockershafts with the solenoid valves towards camshaft sideof the engine.

NOTICEBe sure engine brake housings do not interfere withwiring harness.

Figure 3-6

6. Lubricate each hold-down bolt with clean engine oilbefore installation. Locate the bolts into brake housings.Three bolts are required for engine brake housing. Usehand tools only.

CAUTIONThe use of impact or high-speed wrenches maydamage the cylinder head.

Figure 3-7

7. Before tightening the brake housings hold-down bolts,push the housing from side to side as shown on the abovefigure. Locate the brake housing in the center position ofthe movement.

Figure 3-8

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8. Tighten the engine brake housing hold-down boltsusing the following tightening sequence:a) Torque the three bolts on the camshaft side of theengine to 40 lbft. (55 N*m).b) Torque the six hold-down bolts on the exhaustmanifold side of the engine to 40lbft. (55N*m).c) Repeat the same tightening sequence and re-torqueall hold-down bolts to 100 lbft. (136 N*m).

Figure 3-9

9. Attach the three wires to the solenoids. Make sure offull engagement within the mating terminals.

10. Secure the wiring harness to spacer bars. Make sureharness is free of interference from brake housings androcker levers.

Slave Piston Adjustment

The slave piston adjustment procedure must be strictlyfollowed. Adjustment of the slave piston is critical. Properadjustment is necessary in order to provide peak brakingefficiency without over stressing the engine.

Slave piston adjusting screw adjustment must bemade with the engine stopped and enginetemperature stabilized below 140 ºF (60°C).

Figure 3-10

1. Back out the bridge leveling screw until the end ofthe screw is beneath the surface of the bridge.

Figure 3-11

2. The exhaust valves on the cylinder to be adjusted mustbe in the closed position. Determine which cylinders haveclearance between exhaust rocker adjusting screws and valvestems (rocker arm loose), indicating that exhaust valves arefully closed. Usually four cylinders show the above conditionregardless of the crankshaft position.

3. Refer to the Application Chart to select the correct feelergauge size.

APPLICATION CHARTENGINE CONTROL TECBRAKE LASHMODEL TYPE MODEL SETTING6067GU40 DDECII T760A 0.020” (0.50mm)6067WU40 DDECII T760A 0.026” (0.66mm)6067WU60 DDECII T760A 0.026” (0.66mm)6067WK60 DDECIII T760A 0.026” (0.66mm)6067SK60 DDECIII T760A 0.026” (0.66mm)6067GU28 DDECII T765A 0.026” (0.66mm)6067GU60 DDECII T765A 0.026” (0.66mm)6067GU91 DDECII T765A 0.026” (0.66mm)6067GK28 DDECIII T765A 0.026” (0.66mm)6067GK60 DDECIII T765A 0.026” (0.66mm)

4. Place the correct feeler gauge between the solid side ofthe bridge (the side without the leveling screw) and theexhaust rocker arm adjusting screw.

Figure 3-12

5. Turn the slave piston adjusting screw clockwise until aslight drag is felt on the feeler gauge.

5

Figure 3-14

7. Place the same feeler gauge between the bridgeleveling screw and the exhaust rocker arm adjustingscrew. Turn the bridge leveling screw clockwise until aslight drag is felt on the feeler gauge. Hold the screw inposition and tighten the hex nut to 35lbft. (47 N*m). Verifythe clearance by re-inserting the feeler gauge. Repeat ifnecessary.

8. Repeat the adjustment procedure on the remainingcylinders with exhaust valves in closed position. Barthe engine over as necessary to set the remainingexhaust valves in closed position for slave pistonadjustment.

Operational Check

Installation of the brake housings is now complete.Functioning of the brakes should be checked beforeproceeding further.

CAUTIONWear eye protection. When engine is running withvalve covers removed, oil splashing will occur. Takeprecautions to prevent oil contaminating engine andengine compartment.

1. Start the engine and let it idle for a short time.

Figure 3-15

2. Depress and release the top of the solenoid severaltimes to bleed the air from the brake housing. When allof the air has been removed the brake should operateimmediately when the solenoid is depressed.

3. Verify the following on all three housings:

a) Master piston should be moving up and down onto theroller in the injector rocker arm.

b) Slave piston and bridge should be moving up and downonto the exhaust valve rocker arm adjusting screws.

c) Bridge leveling screw should be aligned with exhaustrocker arm adjusting screw.

d) Verify that wiring harness is not in contact with movingparts.

4. Install the rocker cover.a) For one-piece rocker cover tighten the four bolts, starting

with the center bolts and working outwards, to 16 lbft.(22 N*m) torque.

b) For two-piece rover cover refer to installation on DDCService Manual.

SECTION 4- ELECTRICAL SYSTEM INSTALLATION

A) DDECII Engines

Installation of the electrical system involves the mountingof dash switches, a clutch switch, and a relay harness. Anoptional foot switch may be installed in place of the clutchswitch. Wiring harnesses are provided in the kit to completethe installation.

Dash Switches

Dash switches should be installed in dash where they arevisible and convenient to operate.

1. Drill holes in dash to accommodate switches and installswitches with proper name plates.

Figure 3-13

6. Hold the screw in position and tighten the lock nut to25lbft. (35 N*m). Verify the clearance by re-inserting thefeeler gauge. Repeat if necessary.

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Clutch Switch

It is recommended that the clutch switch be mountedinside the vehicle cab to protect it from roadcontamination.

Figure 4-2

1. Locate the Weather Pack connector from the thru headharness. Locate the Weather Pack connector from therelay harness. Snap together the two mating connectors.

2. Mount the relay base in a convenient location on thefirewall. Connect the black wire to a chassis ground.

3. Locate or drill a ½” hole on firewall. Run the harnessthrough the firewall, from the engine compartment into thecab. The four wires at the end of harness should now be inthe cab.

4. Route the harness to the dash switches close by the clutchswitch. Pull a loop of green wire from the split loom. Cut thegreen wire and install fast-on terminals on both ends. Insertterminals on clutch switch. Use tape around the split loomto keep green wires in place.

Figure 4-3

5. The remaining white wire on the relay harness must beconnected to wire No. 508 (DDEC cavity A1 upper mostclosest to the engine).

Figure 4-1

1. Mount the clutch switch in a convenient location nearthe clutch pedal so that movement of the clutch pedal willcontact the clutch switch actuator arm. See Figure 4-1.

2. Adjust the clutch switch so that the actuator arm isdeflected from 1" to 1.5" (25 mm to 38 mm) when theclutch is in the up (clutch engaged) position.

3. Check the switch by depressing the clutch. The switchshould “click” to an open electrical position as soon as thefree play in the clutch is taken up. When the clutch isreleased, the switch should “click” to a closed electricalposition.

Relay Harness

Figure 4-4

6. Cut the wire No. 508 about 4 inches from ECM connector.Attach the wire originating from ECM to white wire from relayharness having a butt connector. Crimp the connector anduse a heat shrink tubing to seal the joint. Tape the remainingend of wire No. 508.

7. Connect all wires as shown on Wiring Diagram DDECII.

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B) DDECIII Engines

Installation of the electrical system involves the mountingof dash switches, and connecting thru head harness tovehicle interface harness.

On Series 60 engines equipped with DDECIII, theDDECIII ECM controls the engine brake. The use of relayharness is not required.

NOTICESome DDECIII engines may not have the ECMprogrammed for engine brake operation. Verify byusing a DDR. If any of ECM input switches K2, K3,S3 or T3 reads “NONE”, then the vehicle should betaken to a DDC dealer to enable engine braking.

Dash Switches

Dash switches should be installed in dash where they arevisible and convenient to operate.

1. Drill holes in dash to accommodate switches and installswitches with proper name plates.

2. For DDECIII applications, most vehicles already havea vehicle OEM installed clutch switch to use with cruisecontrol. TecBrake clutch switch will only be required iffor some reason the vehicle does not have a clutchswitch, TecBrake Control Group for DDECIII does notinclude the clutch switch, if required, must be orderedseparately.

Figure 4-5

3. Locate the Metri-Pack connector from the DDC-provided connector. Verify the color and/or number of thetwo wires coming from ECM engine sensor harness.

Label Wire ColorEngine Brake Low 562 OrangeEngine Brake Med 561 Red

Figure 4-6

4. Locate the Metri-Pack connector from the thru-headharness. Snap together the two mating connectors.

5. Identify the color and/or number of wires originating atcavity K2 and K3 from ECM Vehicle Interface Connector.

CAUTIONMake sure that only “negative ground” is input to ECMVehicle Interface terminals K2 and K3 or damages toECM may result.

6. These two wires terminate behind the dash and may begrouped with a wire connected to ground. If these wires arenot present and optional cab harness for DDECIII must beused. Connect these three wires as shown on Wiring DiagramDDECIII.

7. Connect one terminal of ON-OFF dash switch to greenwire No. 953 (battery ground).

NOTICEEngine brake will operate automatically while in cruisecontrol. The brake will come on “low” when road speedincreases a few MPH above the cruise set speed. Ifspeed continues to increase, the ECM will increase thebraking power progressively.

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SECTION 5- ENGINE BRAKE MAINTENANCE

Figure 5-1

The engine brake is designed to be trouble free and doesnot require special maintenance. During regularlyscheduled maintenance, or if a problem occurs, theprocedures described below should be followed.

CAUTION Do not remove any engine brake component whilethe engine running. This may result in personal injury.Use only approved cleaning solvents.

Solenoid Valve

1. Disconnect the electrical lead from the solenoid andremove solenoid with a spanner or socket wrench. Removeand discard the three rubber seal rings.

2. Clean the filter screen and solenoid with solvent thendry with low air pressure.

3. Clean solenoid bore with solvent and wipe dry with papertowel. Be careful not to leave any lint or residue in bore thatmay contaminate brake hydraulic components.

Figure 5-2

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4. Reinstall solenoid valve using three new O -rings.Coat solenoid body with engine lube oil and install upperand center seal rings on solenoid body. Seat lower sealring in bottom bore of brake.

5. Carefully screw in solenoid valve, using care to assureO-rings remain in position and are not twisted or “rolled”.

Figure 5-3

6. Tighten solenoid valve to 5 lbft (7 N*M) torque.

Control Valve

Figure 5-4

1. Press down on control valve cover to relieve springpressure.

2. Remove the hex head cap screw and continuepressing down on valve cover.

3. Slowly remove the cover until spring pressure ceases,then remove the two control valve springs and collar.

4. Remove control valve using needle nose pliers.

5. Wash control valve with solvent.

CAUTION Control valve covers are under load from control valvesprings. Use care when removing control valve coversto avoid injury.

Figure 5-5

6. Push on the check valve ball with a small wire throughthe hole in the bottom of the control valve to make surethat there is spring tension on the ball. The ball should liftfreely with a small amount of force and return quickly tothe seat when the force is removed. Replace the controlvalve if it is defective.

7. Dip the control valve in engine lube oil and install in brakehousing. Control valve should slide in without any binding.Replace control valve if binding occurs.

Figure 5-6

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8. Install both control valve springs and collar in valvebore, install cover and cap screw.

Slave Piston Adjusting Screw

1. Loosen slave piston adjusting screw lock nut, andremove adjusting screw from housing. Clean screw withsolvent.

2. Inspect slave piston adjusting screw on the bottomarea. It should be smooth and free of nicks.

Slave Piston Assembly and Torsion Spring.

Figure 5-7

1. Remove the button head screw and washer thatretains the slave piston return spring.

CAUTION When removing slave pistons wear eye protectionand use proper tools. Slave piston springs are highlycompressed and may cause serious personal injuryif not removed with caution.

2. Remove the bridge and slave piston assembly.Loosen leveling screw lock nut from bridge.

Figure 5-8

3. Remove slave piston assembly. Inspect slave pistonpin for nicks or excessive wear.

4. Clean all parts in solvent. Inspect all components forexcessive wear or damage. Replace parts if necessary.

Figure 5-9

5. Reinstall all components. Install both bridges withleveling screws toward the center of housing. Install theslave piston torsion spring with ends over the bridgegrooves.

CAUTIONPush the torsion spring towards the bridge whiletightening the screw. Failure to do so may result incontact between intake valve adjusting screw andtorsion spring; Serious engine damage may result.

6. Install the button head screw and washer over the centersection of torsion spring. Tighten screw to 15 lbft. (20 N*m).

Accumulator Piston

Figure 5-10

1. Press down on accumulator valve cover to relieve springpressure.

2. Remove the hex head cap screw and continue pressingdown on cover.

3. Slowly remove the cover until spring pressure ceases,then remove the accumulator spring.

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CAUTION Accumulator cover is under load from inner spring.Use care when removing cover to avoid injury.

4. Remove accumulator piston using a magnet.

5. Wash control valve with solvent. Inspect parts forwear or damage. Replace if necessary. Insert piston inbore. Accumulator piston must slide without binding.Replace if binding occurs.

Figure 5-11

6. Reassemble all par ts in reverse order fromdisassembly procedure.

Master Piston

Figure 5-12

1. Remove hex head cap screw, washer and flat springfrom brake housing.

2. Remove master piston from bore. Check masterpiston outside diameter ground surface for nicks or burrs.Piston must slide in bore without binding. Replace if bindingoccurs. Check top surface of piston. Replace piston if thereare cracks or pitting.

3. Clean all parts with approved solvent and lubricate withengine oil.

4. Insert piston in bore. Piston must slide in bore withoutbinding. Replace if binding occurs.

5. Reassemble all parts in reverse order from disassemblyprocedure.

Figure 5-13

6. Make sure spring tabs are aligned with raisedsurface on end of piston. Torque cap screw to 9 lbft(12 N*m)

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TecBrake Inc. P.O. Box 27822 Houston, Texas 77227 ©1999 TecBrake Bulletin No. TB990175A 04/01/99

Detroit Diesel®, Series 60® DDECII® and DDECIII® are registered trademarks of Detroit Diesel Corporation.