Usage:
NOTE: The information supplied in this service letter may not be valid after the termination date of this program. Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.
NOTE: This Program can be administered either before or after a failure. In either case the decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS4714" as Part Number, "7755" as Group Number, and "96" as Description Code.
NOTE: This repair requires the use of a 9U5300 Unit Injector Spring Compressor Group. Be sure to order this service tool prior to scheduling any repairs.
NOTE: Although this Program can be administered either before or after a failure, it is recommended that it be administered before failure. Also, parts should be removed from parts stock and reworked as soon as possible.
Termination Date
October 31, 1992Problem
Fuel Injector Clips may fail on certain 3176 Truck Engines. A new 6I2538 Clip, made from higher strength material, can be installed to increase the reliability and service life of the injector.
Affected Product
Model & Identification Number
NOTE: The following 3176 Truck Engines if not previously reworked and stamped with "3X" next to Serial No. Plate.
3176 (7LG1-749, 7LG751-799, 7LG801-1110, 7LG1112-1278, 7LG1281, 7LG1282, 7LG1284-2057, 7LG2059, 7LG2060, 7LG2062-2100, 7LG2102-2267, 7LG2270, 7LG2272, 7LG2273, 7LG2275, 7LG2276, 7LG2278-2285, 7LG2287-2300, 7LG2302-2353, 7LG2355-2423, 7LG2425-2669, 7LG2671-2678, 7LG2680-2724, 7LG2727-2730, 7LG2733-2894, 7LG2896-3043, 7LG3045-3105, 7LG3107-3216, 7LG3218-3220, 7LG3222-3240, 7LG3242-3247, 7LG3249-3273, 7LG3275-3334, 7LG3336-3382, 7LG3384-3396, 7LG3398-3403, 7LG3405-3407, 7LG3409-3419, 7LG3421-3424, 7LG3426-3429, 7LG3431-3449, 7LG3451, 7LG3452, 7LG3454, 7LG3456, 7LG3458-3460, 7LG3462-3467, 7LG3470, 7LG3471, 7LG3473, 7LG3476, 7LG3479-3483, 7LG3485, 7LG3487-3489, 7LG3491-3500, 7LG3502-3512, 7LG3514, 7LG3515, 7LG3517-3521, 7LG3523, 7LG3525, 7LG3526, 7LG3528-3535, 7LG3537, 7LG3539-3544, 7LG3546-3548, 7LG3550, 7LG3552, 7LG3554, 7LG3556, 7LG3558, 7LG3560-3564, 7LG3566-3571, 7LG3573, 7LG3575-3578, 7LG3581-3586, 7LG3593, 7LG3597-3599, 7LG3601, 7LG3602, 7LG3604, 7LG3605, 7LG3607, 7LG3609, 7LG3610, 7LG3612, 7LG3613, 7LG3616, 7LG3617, 7LG3619, 7LG3621, 7LG3623-3626, 7LG3628-3633, 7LG3636, 7LG3639, 7LG3641, 7LG3642, 7LG3645, 7LG3649, 7LG3650, 7LG3652, 7LG3653, 7LG3655, 7LG3656, 7LG3658-3660, 7LG3662, 7LG3663, 7LG3665-3669, 7LG3671-3675, 7LG3677-3681, 7LG3683-3688, 7LG3690-3696, 7LG3698-3702, 7LG3704-3714, 7LG3717, 7LG3722-3736, 7LG3738, 7LG3739, 7LG3741-3747, 7LG3749, 7LG3750, 7LG3752, 7LG3753, 7LG3755, 7LG3757, 7LG3758, 7LG3761-3765, 7LG3767-3781, 7LG3783, 7LG3785, 7LG3787-3789, 7LG3793, 7LG3796-3799, 7LG3801-3811, 7LG3813-3822, 7LG3827-3830, 7LG3833, 7LG3835, 7LG3837-3847, 7LG3852-3856, 7LG3860, 7LG3862, 7LG3864, 7LG3866, 7LG3868, 7LG3871, 7LG3876, 7LG3877, 7LG3883-3890, 7LG3892, 7LG3893, 7LG3897, 7LG3900, 7LG3904, 7LG3907, 7LG3909-3918, 7LG3920, 7LG3921, 7LG3924, 7LG3927, 7LG3932, 7LG3938, 7LG3941, 7LG3944-3951, 7LG3953, 7LG3954, 7LG3956, 7LG3960, 7LG3962, 7LG3963, 7LG3965, 7LG3966, 7LG3968, 7LG3970, 7LG3973, 7LG3976, 7LG3978-3980, 7LG3983-3989, 7LG3991, 7LG3992, 7LG3994, 7LG3997, 7LG3999, 7LG4001, 7LG4003, 7LG4004, 7LG4007, 7LG4009, 7LG4011, 7LG4013, 7LG4016-4020, 7LG4024, 7LG4025, 7LG4027-4029, 7LG4031, 7LG4033, 7LG4035-4037, 7LG4039-4051, 7LG4053-4055, 7LG4057, 7LG4059-4069, 7LG4071, 7LG4075, 7LG4077-4081, 7LG4083, 7LG4085-4088, 7LG4090-4092, 7LG4094, 7LG4097-4101, 7LG4104, 7LG4105, 7LG4107, 7LG4108, 7LG4110, 7LG4112, 7LG4114, 7LG4116-4122, 7LG4124, 7LG4125, 7LG4127, 7LG4128, 7LG4130, 7LG4132, 7LG4133, 7LG4135, 7LG4137-4139, 7LG4141-4143, 7LG4146, 7LG4148-4150, 7LG4152, 7LG4155, 7LG4159, 7LG4162, 7LG4164, 7LG4168, 7LG4171, 7LG4172, 7LG4174, 7LG4176, 7LG4183, 7LG4186, 7LG4188, 7LG4190, 7LG4195, 7LG4198, 7LG4200, 7LG4203, 7LG4205, 7LG4206, 7LG4210-4212, 7LG4214, 7LG4215, 7LG4217, 7LG4219, 7LG4220, 7LG4223, 7LG4225, 7LG4226, 7LG4228, 7LG4230, 7LG4234, 7LG4235, 7LG4237, 7LG4239, 7LG4242, 7LG4244, 7LG4245, 7LG4247, 7LG4249, 7LG4250, 7LG4252-4257, 7LG4259, 7LG4260, 7LG4262, 7LG4264, 7LG4266, 7LG4268, 7LG4271, 7LG4273, 7LG4276, 7LG4279, 7LG4283, 7LG4284, 7LG4286, 7LG4296, 7LG4297, 7LG4299, 7LG4308, 7LG4314, 7LG4316, 7LG4318, 7LG4320-4323, 7LG4325, 7LG4327-4329, 7LG4331-4342, 7LG4344-4348, 7LG4350-4354, 7LG4356, 7LG4358, 7LG4360, 7LG4361, 7LG4366, 7LG4368, 7LG4370, 7LG4372, 7LG4375, 7LG4381, 7LG4383, 7LG4386, 7LG4389, 7LG4398-4401, 7LG4403, 7LG4410, 7LG4412, 7LG4413, 7LG4415, 7LG4416, 7LG4418, 7LG4419, 7LG4421, 7LG4423-4425, 7LG4427, 7LG4430, 7LG4431, 7LG4433, 7LG4437, 7LG4440, 7LG4456, 7LG4459, 7LG4460, 7LG4462, 7LG4464, 7LG4466, 7LG4470, 7LG4472, 7LG4474, 7LG4484, 7LG4490, 7LG4492, 7LG4493, 7LG4495, 7LG4497, 7LG4499, 7LG4503, 7LG4505, 7LG4508, 7LG4509, 7LG4521, 7LG4522, 7LG4526, 7LG4535, 7LG4541, 7LG4562, 7LG4563, 7LG4586, 7LG4592, 7LG4631, 7LG4633, 7LG4671-4673, 7LG4675, 7LG4677-4679, 7LG4681-4685, 7LG4691, 7LG4699, 7LG4711, 7LG4745, 7LG4751, 7LG4768, 7LG4774, 7LG4804, 7LG4821, 7LG4822)
Parts Needed
- 6 - 6I2538 Clip
NOTE: Add injectors and related seals if clip is broken in more than three pieces. Add 336044 O-Ring Seal if thrust pad o-ring is damaged.
Action Required
Parts Stock
Remove all of the following injector groups from parts stock. Rework as described in the attached procedure and return to stock.
- 4P1410 Injector Group
- 4P1420 Injector Group
- 4P2810 Injector Group
- 4P2820 Injector Group
- 4P9510 Injector Group
- 4P9520 Injector Group
- 4P9610 Injector Group
- 4P9620 Injector Group
- 0R3177 Injector Group
- 0R3178 Injector Group
- 0R3400 Injector Group
- 4P1420 Injector Group
Affected Product
Rework the injector groups as described in the attached procedure.
Service Claim Allowances
Parts Stock
Submit one claim for all injector groups removed from parts stock and reworked. List the labor to repair each injector on a separate labor line. A maximum of .2 hours labor per fuel injector will be allowed to remove and install the clip.
Affected Product
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
- (1-Rework Procedure)
Attach.
Rework Procedure
Parts Stock or Off Engine
Illustration 1 - 9U5300 Unit Injector Spring Compressor Group
Illustration 2 - Compressor Group In Bench Vice
Illustration 3 - Use caution when handling injectors with missing clips. Loose springs and retainers will allow ball to come loose and fall into the engine.
1. Remove injectors from packaging and inspect for a paint stripe across the top face of the spring retainer (either yellow or red). The paint stripe indicates the unit injector has been reworked previously.
NOTE: If a clip has failed and the spring/tappet/plunger are loose, use care during injector removal. The plunger retention ball (see Illustration 3) can drop out and fall into the cylinder/engine.
2. Install service tool in a bench vice as shown in Illustration 2 (position to allow for horizontal installation of injector).
3. Use an o-ring pick to remove the o-ring from the injector spring retainer. Remove the rocker arm thrust pad.
4. Install the injector in the 9U5300 Unit Injector Spring Compressor Group. Tighten the 5P0541 Nut to compress the spring enough to allow removal of the clip (the clip works like a valve keeper).
5. Use a small magnet (pencil size works best) and a suitable clip removal tool to remove the oil clip from the injector.
NOTE: Do not release tension on the spring until a new clip is installed. Releasing tension before a new clip is installed will cause the injector will come apart.
6. Injectors removed from engines only. Inspect the clip that was removed. If the clip is broken in more than three (3) pieces (or if you suspect small pieces have fallen into the injector) the unit injector must be replaced.
7. Install a new 6I2538 clip and remove injector from spring compressor group.
8. Install thrust pad and thrust pad retaining o-ring.
NOTE: If the thrust pad retaining o-ring is damaged install a new 336044 O-Ring Seal.
9. Mark across the top face of the spring retainer with a yellow paint stripe.
10. Repackage new parts and mark "3X" on the box.
Affected Product
1. Check for 3X stamped on the block next to the serial number plate. If the block has been stamped do not proceed with the rework unless suspect injectors have recently been installed in that engine. Check SIMS history to be sure.
2. Remove valve covers, Jake Brake (if equipped) and rocker arm groups. Inspect unit injectors for a paint stripe across the top face of the spring retainer (either yellow or red). A paint stripe indicates the unit injector has been reworked previously.
3. Remove the return to tank fuel line at the fuel manifold adapter (siphon break) and install a 0-100 psi gage at the manifold.
4. Use an o-ring pick to remove the o-ring from the spring retainer of each injector to be reworked. Remove the rocker arm thrust pad from each injector.
5. Pressurize fuel system using the priming pump to 30 psi and maintain pressure from 15-30 psi during rework (fuel pressure keeps the injector plunger extended during clip replacement).
6. Inspect the 9U5300 Unit Injector Spring Compressor Group. See Illustration 1. The 9U5320 Fixture is for off engine use only.
Install the compressor group into a rocker arm support bolt hole with the arm aligned over a unit injector spring. Be sure the 5P0541 Nut is backed off to the top of the 9U5321 Tube before tightening the 7X0909 Bolt.
NOTE: Install the compressor at hole locations closest to the inlet valves.
Tighten the 5P0541 Nut to compress the injector spring only enough to allow removal of the clip (the clip is like a valve keeper).
7. Use a small magnet (pencil size works best) and a suitable clip removal tool to remove the old clip from the injector.
NOTE: Do not release tension on the spring until a new clip is installed. Releasing tension before a new clip is installed will cause the injector will come apart.
8. Inspect the clip that was removed. If the clip is broken in more than three (3) pieces (or if you suspect small pieces have fallen into the injector) the unit injector must be replaced.
9. Install a new 6I2538 Clip and remove the spring compressor group
10. Replace the thrust pad and the thrust pad retaining o-ring.
NOTE: If the thrust pad retaining o-ring is damaged install a new 336044 O-Ring Seal.
11. Mark across the top face of the spring retainer with a yellow stripe and proceed with rework to the remaining injectors.
12. After completion of the rework, stamp "3X" on the cylinder block near the Serial Number Plate.