PLATE 5210769 - 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 "PS4278" 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 April 12, 1998 Service Letter. Changes have been made to the Problem description for both groups.
Termination Date
April 30, 2000Problem
Group 1
The conveyor may stall out during the first loads of asphalt or the conveyor/auger may continue to run after the system is shut down due to broken valve springs in the 135-2511 valve kit on certain AP-1050B and AP-1055B Asphalt Pavers; and on certain Barber-Greene BG-245C and BG-2455C Asphalt Pavers manufactured by Caterpillar. The valve kit should be replaced with 149-2920, the conveyor sprocket may be changed to increase the amount of startup torque available to the conveyor/auger and the compensation pressure may be increased to 4,000 PSI.
Group 2
The conveyor may stall out during the first loads of asphalt on certain AP-1050B and AP-1055B Asphalt Pavers; and on certain Barber-Greene BG-245C and BG-2455C Asphalt Pavers manufactured by Caterpillar. The compensation pressure may be increased to 4000 PSI and the conveyor sprocket may be changed to increase the amount of startup torque available to the conveyor.
Affected Product
Model & Identification Number
Group 1
AP-1050B (6ZN1-170)
AP-1055B (8BM1-215)
BG-245C (4XN1-115)
BG-2455C (6TN1-130)
Group 2
AP-1050B (6ZN171-189)
AP-1055B (8BM216-287)
BG-245C (4XN116)
BG-2455C (6TN131-136)
Parts Needed
Group 1
2 - 1371954 Sprocket As4 - 1492920 Valve Kit2 - 1541421 Coil2 - 1541422 Valve-SolenoidGroup 2
2 - 1371954 Sprocket As2 - 1541421 Coil2 - 1541422 Valve-SolenoidAction Required
See the attached rework procedure.
Service Claim Allowances
This is a 10-hour job.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
Attach.(1-Rework Procedure)Rework Procedure
Valve Kit, Dump Solenoid and Sprocket Replacement Procedure.
Replace (A) the feeder and auger valve kits on both left and right 115-0060 Control Valve Assemblies with part number 149-2920 Valve Kit.
Valve Kits with a date code of 722 or a Vickers part number of MOSI-5628 do not need replacement.
Item "A" pilot valve and main spool valves are a matched set.
1. Replace (B) the dump valve and solenoid on both left and right 115-0060 Control Valve Assemblies with part numbers 154-1422 Valve Solenoid and 154-1421 Coil.
Illustration 1If quick disconnect nipples are not installed, add the following to ports G1 and G2:
Illustration 2.2. Start the machine and allow the system to warm up.3. Check and adjust both the left and right compensator pressures using