LABEL,MS120 0938977 - Caterpillar

Caterpillar: Confidential Yellow
PSP FOR SHORT SERVICE LIFE OF BRAKES ON D11N TRACTORS IN STEEP SLOPE OR HIGH TRAVEL SPEED APPLICATIONS - MAILED US AND CANADA, CO SA, 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-129 A-59.2 AU-79 O-73 4005 PS0345 This Program can only be administered after a failure occurs. The decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS0345" as Part Number and "7755" as Group Number. Termination Date
August 31,1989
Problem
The service life of the brakes when D11N Tractors are used in steep slopes or high travel speed applications has not been acceptable. These applications can cause heat build up in the brakes and result in overheating of the power train oil and/or warpage of the brake separator plates. The brake group can be changed from an 8 disc group to a 10 disc group.
Affected Product
Model Identification Number D11N 74Z1 - 456
Parts Needed
8 - 6Y2052 Spring 2 - 6T840 Seal 2 - 6Y2115 Ring 2 - 6T839 Seal 2 - 6Y2046 Piston 2 - 8P9568 Seal 20 - 6Y4250 Disc 2 - 6T838 Seal 18 - 6Y4251 Plate 6 - 9G2991 Seal 2 - 6Y1775 Retainer 2 - 5P4057 Seal 2 - 6Y1777 Piston 4 - 8M4389 Seal 2 - 6Y2138 Hub 6 - 6F6673 Seal 2 - 6Y1776 Retainer As. 2 - 6Y1774 Housing 24 - 5L4398 Bolt 2 - 6Y1778 Plate 2 - 6Y1773 Hub
Action Required
Dealer Exchange Units Remove all 6T0690 Brake And Steering Clutch Groups from dealer stock and