SUSPENSION & MTG GP-FRONT 3288956 - Caterpillar

Caterpillar: Confidential Yellow
PSP FOR REPAIRING STICKING VALVES IN THE AIR COMPRESSOR ON CERTAIN 12G, 120G, 130G, AND 140G MOTOR GRADERS; 518 SKIDDERS; AND 936E AND 950E LOADERS - PS4512 - MAILED US AND CANADA, COFA, CFEL, COSA
  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.
U-174 A-119 AU-112 E-104 O-133 1803 PS4512 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 "PS4512" as Part Number, "7755" as Group Number, and "96" as Description Code. Although this Program is to be administered as described above on the Affected Product, parts should be removed from parts stock as soon as possible. Termination Date
August 31, 1991
Problem
The valves in the air compressor on certain 12G, 120G, 130G, and 140G Motor Graders; 518 Skidders; and 936E and 950E Loaders may stick and result in a condition of "no air at startup."
Affected Product
Model Identification Number 12G 61M11413-13706 3WC933-1379 120G 4HD630-1213 87V7884-9203 11W1218-1311 130G 74V2258-2491 12W1065-1089 140G 5MD275-886 72V9343-12874 13W740-790 518 94U1519-2273 95U1461-2734 936E