Product Support Program For Inspection And Update To The Fuel Transfer Pump, Boost Line, And Throttle Position Sensor On Certain 3176 Truck Engines Caterpillar

Product Support Program For Inspection And Update To The Fuel Transfer Pump, Boost Line, And Throttle Position Sensor On Certain 3176 Truck Engines

Usage:

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Caterpillar: Confidential Yellow

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 "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.

NOTE: 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, 1992

Problem

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)

NOTE: 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)

NOTE: 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).

NOTE: 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 Cover

Add For replacing Transfer Pump:

1 - 8C0624 O-ring Seal (pump to engine)

1 - 3K0360 O-ring Seal (connector)

1 - 4P3777 Fuel Transfer Pump

1 - 9X6650 Connector (2YG1 - 9702 only)

Boost Line Modification

1 - 016449 Adapter

1 - 9Y6139 Hose

1 - 3J7355 Union

1 - 9L8493 Cap

Throttle 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. If evidence of moisture is found, clear restriction and drain water from boost line. Install boost line to transducer.

2. Remove plug on top of the manifold and install 016449 Adapter. See Illustration 1.

Illustration 1. Boost Line Rework

3. Remove boost line from the end of the manifold, plugging the fitting with 9L8493 Cap.

4. Install new hose and union between existing hose end and adapter. Secure boost line to compressor hose to avoid chafing.

Throttle Position Sensor

Inspect the throttle linkage for loose, bent, broken, missing, or worn components. Also, check for interference with the linkage or spring. The throttle should work smoothly without excessive drag and return to low idle position without assistance in less than one second. Repair linkage as authorized by the OEM dealer.

Additional Reference:

2YG - SENR3913 Troubleshooting Guide, Procedure P-303

7LG - SENR5112 Troubleshooting Guide, Procedure P-303

Tool Requirements:

1 - 8T8697 Electronic Control Analyzer and Programmer

1 - NEXG4522 3176 Engine SPM for 8T8697 ECAP

1 - 8T5275 Harness

1 - 8C9801 PWM Adapter Group

1 - 8T8695 9 - Pin Breakout "T"