Caterpillar — P-36 Engine Brake Installation on Caterpillar 3406 Truck Engine

A Caterpillar service procedure — check it applies to your exact model before use.

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Procedure

1. Identify the engine model and examine the valve cover identification tag.
2. Thoroughly clean the top of the engine, remove the crossover pipe and rocker covers.
3. Loosen and remove fuel lines, place in protective bag.
4. Loosen the intake and exhaust rocker arm adjusting screw lock-nuts.
5. Remove the front rocker shaft group from the engine (no more than three rocker assembly head bolts at a time).
6. For engines with serial numbers prior to 7FB-39279, measure the height of the two end pedestals using a vernier caliper or micrometer. If more than 0.005 difference is noted, machine down the higher pedestal or use shimming.
7. Remove the Caterpillar exhaust rocker arm adjusting screws and replace them with hardened hexhead Pacbrake screws. Reuse the Caterpillar lock-nuts.
8. Remove the exhaust valve crossheads, remove crosshead adjusting screws and locknuts, then loosely install them into the Pacbrake crosshead.
9. Apply clean oil to the crosshead bore, install on the engine, and adjust according to Caterpillar manual.
10. Check clearance between the underside of the cross-head on the adjusting screw side and the top of the valve rotocoil.
11. Remove the front dowel pin from each rocker arm assembly. Lubricate the Pacbrake oil supply adapter and install it with approximately 0.020 gap between rocker arm pedestal and adapter body.
12. Remove the rear locating pin and replace with the longer Pacbrake pin (rounded end up), drive until it stops on the bottom inside of the rocker shaft.
13. Use air pressure to remove oil trapped in holddown bolt holes (wear eye protection).
14. Re-install the front rocker assembly, ensuring push-tubes are in place.
15. Install two Pacbrake studs with washers in outside locations on rocker shaft. Reuse Caterpillar bolt and washer in center locations.
16. Center the rocker assembly and snug studs and bolts firmly.
17. Starting with center bolt, torque bolts and studs to 200 lbs.ft (270 N.m), then torque again to 330 lbs.ft (450 N.m) in 50 lb (70 N.m) increments.
18. Repeat steps 4-14 on rear rocker assembly.
19. Remove Caterpillar head bolts on the front of the engine, perform oil blow-out procedure, lubricate bolt threads and bearing surfaces.
20. Install Pacbrake support base in these locations reusing Cat head bolts and washers, torque to 330 lb.ft (450 N.m).
21. Install housing support studs into support bases (hex nut end into base), torque with 9/16 crowfoot wrench to 50 lb.ft (70 N.m). Install 7/16 NF nuts and washers, run to bottom of threads.
22. Repeat steps 16-18 on rear.
23. Set intake and exhaust valves according to Caterpillar manual. If using shim, add above stud hex and below hardened steel washer.
24. Re-install fuel tubes, torque to Caterpillar specifications (35 lb.ft, 50 N.m).
25. Note that each engine brake housing is designated FRONT or REAR, marked on the distributor body.
26. Install and lubricate the oil supply adapter o-ring. Lubricate the housing oil supply adapter bore.
27. Install the front housing over the studs and oil supply adapter, hold level to minimize damage to o-ring.
28. Ensure housing is fully down and location pin has engaged with milled locating groove on undersurface.
29. Install 3/4 N.F. nuts with remaining Pacbrake washers on housing holddown studs. Ensure 7/16 N.F. support bracket nuts are not in contact with housing.
30. From turbo side, starting with left holddown nut, torque both evenly in two steps: 50 lb.ft (70 N.m), then 100 lb.ft (140 N.m).
31. Repeat steps 23-27 on rear of engine.
32. Turn support bracket nuts up under housings as tight as possible using fingers only. Install upper washers and nuts, torque to 50 lb.ft (70 N.m).
33. Perform slave piston adjustment at any location where exhaust crosshead is loose. Insert Pacbrake feeler gauge between slave piston feet and crosshead, turn adjusting screw until slight drag is felt, torque lock-nut to 25 lb.ft (35 N.m), re-check clearance.
34. Install Caterpillar valve cover bases with four studs and washers on each base. Use Caterpillar screws in other locations. Ensure proper clearance between Pacbrake crossheads and cover bases.
35. Install two types of terminal lead-out bushings (both installed the same way). Apply clean lube oil to seal ring and tighten until seated.
36. Install Pacbrake gaskets in spacers, leaving approximately 1/8 inch gap at each end for expansion.
37. Install spacers over base mounting studs.
38. Install Pacbrake serrated nuts and capscrews in proper locations, tighten evenly to 13 lb.ft (18 N.m).
39. Install solenoid wire on spacer lead-out terminal.
40. Double-check installation, start engine and idle 5-10 minutes.
41. With engine running, hold clean rag over control valve covers to catch oil spray. Depress solenoid 5-6 times to purge air from engine brake housings. Check for abnormal oil or fuel leaks.
42. Before installing Caterpillar valve covers, check for interference at oil filler or breather locations. Remove cover material if necessary.
43. Install valve covers, torque holddown screws to 13 lb.ft (18 N.m). Relocate breather pipe and install extension hose.
44. Install electrical wiring according to engine type (Mechanical, PEEC II, or PEEC III). Engines can have different electrical system types requiring different wiring groups.
45. For mechanical systems: Remove idle adjusting screw from fuel pump and replace with throttle switch from kit. Adjust according to Caterpillar specifications. Tighten locknut to 5 lb.ft (7 N.m).
46. For PEEC II systems: Install Pacbrake switch and bracket assembly using existing mounting bolt. Mount actuating arm with spacer and shake-proof washers. Set actuating arm so switch is in closed position when sensor is at idle, lock 1/4-20 capscrew at 125 lb.in (14.2 N.m).
47. Operate throttle to ensure switch is actuated each time throttle returns to idle position.

Source: manual:L2001.pdf. Figures and steps are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.