SPRING-RETURN 4D5262 - Caterpillar

Caterpillar: Confidential Yellow
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.
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 "PS4675" as the Part Number and "7755" as the Group Number. If administered before failure, use "56" as the Warranty Claim Description Code and use "T" as the SIMS Description Code. If administered after failure, use "96" as the Warranty Claim Description Code and use "Z" as the SIMS Description Code.
Some of the Affected Product fall into more than one group. Do all applicable portions of this Service Letter at the same time. Also, when applicable, this program should be done in conjunction with the September 3, 1991 Service Letter, "Product Support Program For Installing New Connecting Rod Bearings In Certain 3176 Truck Engines".
Termination Date
December 31, 1992Problem
Certain 3176 Truck Engines may experience the following: (1) The fuel transfer pump cover has been replaced with a cover that has the priming bypass valve installed on the outlet pressure side. (2) The turbo boost line may become plugged and may reduce engine performance. (3) Incorrect throttle linkage adjustments may cause low power or rough engine operation.
Affected Product
Model & Identification Number
Fuel Transfer Pump
3176 (2YG1-6318)
This Program does not apply if SIMS indicates that a new fuel transfer pump cover has already been installed. (Rework "Code I" on SIMS)
Boost Line Modification
3176 (2YG1-Up)
This Program does not apply if SIMS indicates that a the boost line modification has already been installed. (Rework "Code P" on SIMS)
Throttle Position Sensor
3176 (2YG1-Up*;7LF1-Up*)
*Not applicable if equipped with a 9X8151 Control Group (Pedal Mounted throttle Position Sensor). This Program does not apply if SIMS indicates that a throttle adjustments have already been made. (Rework "Code Q" on SIMS)
Parts Needed
Fuel Transfer Pump
Replace Cover:
1 - 8C0624 O-ring Seal (pump to engine)1 - 8C5197 O-ring Seal (cover)1 - 4P0989 Fuel Transfer Pump CoverAdd For replacing Transfer Pump:
1 - 8C0624 O-ring Seal (pump to engine)1 - 3K0360 O-ring Seal (connector)1 - 4P3777 Fuel Transfer Pump1 - 9X6650 Connector (2YG1 - 9702 only)Boost Line Modification
1 - 016449 Adapter1 - 9Y6139 Hose1 - 3J7355 Union1 - 9L8493 CapThrottle Position Sensor
No Parts required
Action Required
Fuel Transfer Pump
1. Remove the fuel transfer pump (front and rear cover bolts hold the pump to the engine.2. Remove the transfer pump cover.3. Inspect fuel transfer pump/gears (If fuel transfer pump damage has occurred, replace with a 4P3777 Pump and the necessary parts listed.4. Install 4P0989 Fuel Transfer Pump Cover using new 8C5197 O-ring.5. Install fuel transfer pump using new 8C0624 O-ring.6. If fuel transfer pump damage has occurred, remove hand priming pump and inspect valves for damage and debris. Repair and clean as necessary.Boost Line Modification
1. Remove boost line from transducer and check for presence of water or corrosion.