VALVE GP-BANK 5 9T3240 - Caterpillar

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 "PS4310" 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.
This Revised Service Letter replaces the June 25, 1998 (Revised August 1998) Service Letter. Changes have been made to the TERMINATION DATE.
Termination Date
June 30, 2000Problem
The torque limiter needs to be reworked to improve hydraulic performance on certain 416C, 426C, 428C, 436C and 438C Backhoe Loaders. The torque limiter can reduce the hydraulic flow too much when in a multi function application (when compared to the B-series Backhoe Loader). This is caused by a lower torque limiter setting and for potential yielding of the torque limiter control spring on the C-series Backhoe Loaders. This fix will not address lift problems or lack of force problems.
Affected Product
Model & Identification Number
416C (4ZN1-5635, 5YN1-3800, 1WR1-2947, 1XR1-684)
426C (6XN1-1245, 7WN1-439, 1CR1-364, 1MR1-456, 1YR1-517, 1ZR1-400)
428C (8RN1-1629, 2CR1-4432)
436C (8TN1-391, 2AR1-604, 2BR1-212, 1FR1-416, 1PR1-598)
438C (9KN1-561, 1JR1-607, 1TR1-784, 2DR1-1053)
Parts Needed
1 - 1555111 Kit - Torque Limiter (Turbocharged)1 - 1558324 Kit - Torque Limiter (Naturally Aspirated)Action Required
See the attached Rework Procedure.
Service Claim Allowances
This is a 3-hour job.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
Attach.(1-Rework Procedure)Rework Procedure
The changes described in this program are to address problems with multi function cycle times (speed) and/or excessive engine lug. This change will not correct problems of force (i.e. stick force complaints - inability of the machine to lift above our ratings, etc.).
Make sure machine is parked on level surface, engine shutoff and parking brake applied.Also, make sure all implements are lowered to the ground and system pressure has been relieved from all hydraulic circuits before any work begins to perform this rework.
1. Follow all Safety warnings and procedures outlined in the service manual or given on decals on the machine.2. Provide a method of collecting any oil loss that may occur when doing rework. Tools Required:
- Flow meter, (45 gpm minimum) and variable relief valve- Accurate tachometer (do not use vehicle tachometer)- 5000 psi pressure gauge- Differential pressure gauge- Differential pressure gauge- 3 mm Allen wrench- 5 mm Allen wrench- and inch open end wrench Tool Installation:
1. Install 0 to 5000 psi gauge on pump discharge tap.2. Install flow meter and variable relief valve between the boom cylinder hoses. Direction of flow must be from rod end to head end. This should form a circuit from the one port of the boom valve through the hose to flow meter through a hose to the other port of the boom valve.3. Install accurate tachometer. (Do not use vehicle tachometer)4. Provide means to measure hydraulic oil temperature. System Pressure Verification:
1. Activate bucket curl and hold in position