SOCKET-20MM 9U6525 - Caterpillar

Caterpillar: Confidential Yellow
SERVICE LETTER EXTENSION FOR APRIL 20, 1988 SL - PSP FOR PISTON SKIRT SCUFFING ON 776B TRACTORS AND 777B, 785, 789 TRU CKS - MAILED US AND CANADA, LIMITED CACO
  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-135 A-90.1 The Termination Date has been extended for the following Service Letter. Change the Termination Date to April 30, 1991. April 20, 1988 - PS4218; Product Support Program For Piston Skirt Scuffing On 776B Tractors and 777B, 785, 789 Trucks