PLATE-MOUNTING 2018394 - Caterpillar

Caterpillar: Confidential Yellow
PSP FOR INSTALLING 9C645 PISTON KITS:IN BRAKE GROUPS ON 824C WHEEL TRACTORS, 980C WHEEL LOADERS; IN SLACK ADJUSTERS ON 992C WHE EL LOADERS PS4027 - MAILED US AND CANADA
  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.
PRODUCT SUPPORT PROGRAM FOR INSTALLING 9C0645 PISTON KITS: IN BRAKE GROUPS ON 824C WHEEL TRACTORS, 980C WHEEL LOADERS; IN SLACK ADJUSTERS ON 992C WHEEL LOADERS, 4250, 4251, 4261, PS4027 U-2 C-2 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 "PS4027" as Part Number and "7755" as Group Number. Some owners of the affected product in this Program also have off-highway trucks and tractors affected by another Program, PI3100, dated November 7, 1985. Dealers may want to administer this Program (PS4027) at the same time they administer the other Program (PI3100). Although products in the field are to be administered as described above, dealers should rework immediately parts stock of brake groups and slack adjusters within date codes indicated. Termination Date
January 31, 1987
Problem
A 9V3222 Piston Assembly is installed in the brake line to each service brake. On the 824C Wheel Tractor and 980C Wheel Loader each piston assembly is in a housing attached to a service brake group. On the 992C Wheel Loader two piston assemblies are installed in each (slack) adjuster group -- one slack adjuster for front service brakes and one for rear service brakes. Piston assemblies can leak because seal material is not correct. Leakage causes slow actuation of service brake(s). Correct seal material is now used, and parts can be identified by a date code.
Affected Product
Model Identification Numbers 824C 85X1007-1078, 1080-1086, 1088-1117, 1120, 1121, 1123-1125, 1128-1145, 1149, 1150, 1153, 1155-1157 980C 63X4950-5650, 5652-5788, 5790-5798, 5801, 5803, 5805, 5806, 5808-5816, 5818-5863, 5865-5891, 5894, 5896, 5899, 5900, 5902, 5903, 5905, 5908-5910, 5914, 5921, 5924, 5926, 5928-5931, 5933-5987, 5989-5999, 6001-6003, 6006, 6009, 6014, 6018, 6020, 6022-6025, 6027, 6029, 6030, 6034, 6038, 6040, 6042, 6044, 6045, 6047, 6050-6053, 6063-6066, 6068, 6072, 6074, 6077-6083, 6096, 6097, 6099, 6103, 6105, 6110, 6120-6139, 6141-6146, 6148, 6150-6155, 6159, 6160, 6164 992C 49Z369-592, 594-607, 610-619, 623, 624, 627, 629, 633-661,