DISC 4422857 - Caterpillar

Cleaning Of Unit Injector Barrel
Illustration 9: (1) Case. (2) Unit injector body. (3) Tappet spring. (4) Tip assembly (part of check assembly). (5) Check (part of check assembly). (6) Stop (part of check assembly). (7) Sleeve (part of check assembly). (8) Spill deflector. (9) Spring (check). (10) Plate. (11) Barrel (part of plunger assembly). (12) Injector plunger (part of plunger assembly). (13) Plunger gear (part of plunger assembly). (14) Retainer. (15) Rack. (16) Tappet retainer pin. (17) Keeper. (18) Tappet assembly.1. Place a unit injector body in Pedestal (Tool B) with the tip up.This will allow cleaning fluid to drain from barrel (11).2. Flush barrel (11) with cleaning solution filtered to the 5 micron level.Use clean 6V-6067 or 6V-6068 Test Fluid or equivalent test fluid that meets SAE967 or ISO4113 Standards as a cleaning solution.A 6V-7093 Brush Assembly can be used to remove varnish deposits.Do NOT remove barrel (11) from the unit injector. The barrel can NOT be removed from the unit injector without complete disassembly.Complete disassembly is NOT recommended because doing so will require factory calibration.Inspection Of Rack
Illustration 10: (15) Plunger rack. (M) Location. (N) Location.
Illustration 11: (1) Case. (2) Unit injector body. (3) Tappet spring. (4) Tip assembly (part of check assembly). (5) Check (part of check assembly). (6) Stop (part of check assembly). (7) Sleeve (part of check assembly). (8) Spill deflector. (9) Spring (check). (10) Plate. (11) Barrel (part of plunger assembly). (12) Injector plunger (part of plunger assembly). (13) Plunger gear (part of plunger assembly). (14) Retainer. (15) Rack. (16) Tappet retainer pin. (17) Keeper. (18) Tappet assembly.1. Inspect plunger rack (15) for wear and to ensure it is straight.Rack teeth at location (M) must be smooth.Any wear marks that can be felt with a pencil point are an indication that the rack is worn too much and that the unit injector should be replaced.2. Inspect the surface condition at both locations (N) on the collar.If any wear marks at either location (N) can be felt with the finger, it is an indication that the rack is worn too much and the unit injector should be replaced.3. Locations (N) on the collar must be parallel with each other. If the surfaces are NOT parallel, it is normally an indication that the rack collar is bent.4. To check for a straight rack, install rack (5) in unit injector body (2). Rack (15) must slide in and out freely. The final check to see if the rack is straight will be made when the unit injector is completely assembled.Inspection Of Injector Body And Case
Illustration 12: (P) Bore. (R) Slot. (S) Surface. (T) Location of case (1). (U) O-ring seal groove.1. There must not be any nicks or burns in, or around, O-ring seal grooves (U) or on the taper at location (T) of case (1).Use emery cloth to carefully remove any nicks or burns at either location.2. Inspect unit injector body at bore (P), slot (R), and surface (S):BORE (P) AND SLOT (R): Bore (P)