TUBE 4556672 - Caterpillar

Illustration 1 g00616516
(1) Follower (2) Thrust plate
Check the rocker arms and the rocker arm bolts for cracks, wear, or damage. Tighten the rocker arm bolts evenly to a torque of 33 7 N m (24 5 lb ft).
Check the contact between the rocker arm and the injector. If follower (1) for the rocker arm is missing, replace the follower. Ensure that thrust plate (2) is in position on top of the injector. If the thrust plate is not found, check the valve compartment. If the thrust plate is located and the thrust plate is undamaged, reinstall the thrust plate. Use a new O-ring if the thrust plate is reinstalled. Replace the injector if the thrust plate is not found. Also replace the injector if the thrust plate is found but the thrust plate is damaged.
Illustration 2 g00615272
(3) Fuel injection rack (4) Cone (5) O-ring
Move each fuel injection rack (3) in order to check for binding. If a fuel injection rack is binding, use the following procedure to correct the problem.
Remove the rocker stand and remove the hold-down bolt for the unit injector. Rotate the injector in the cylinder head. The fuel injection rack may now be disconnected from the linkage.
Do not remove the fuel control linkage or the fuel injection racks without having the spring compressors installed. Damage to the injectors may occur.
Use a 1U-6675 Spring Compressor to compress the fuel injector spring.
Move the fuel injection rack. If the fuel injection rack is still binding, replace the injector.
Verify synchronization and timing after an injector is reinstalled or an injector is replaced. Refer to the System Operations, Testing And Adjusting module. If the fuel injection rack is no longer binding, the injector may have been seated incorrectly.
Ensure that the fuel injection rack is centered. Ensure that the ball for the fuel control linkage is centered. Torque the bolt for the injector hold-down bracket to 12 3 N m (106 27 lb in).
Ensure that all of the hold down bolts for the injectors are tightened to a torque of 12 3 N m (106 27 lb in). If an incorrectly tightened bolt is found, remove the injector that is held down by the bolt. Examine the sealing surface for the injector sleeve. Ream the injector sleeve if the seat area for the injector is pitted. Replace the injector sleeve, if necessary. Replace the injector only if injector cone (4) is damaged. A burned O-ring or a missing O-ring on the end of the injector does not indicate a faulty seal. The O-ring does not need to be replaced. Verify synchronization and timing after an injector is reinstalled or an injector is replaced. Refer to the System Operations, Testing And Adjusting module.