DAMPER AS 10R0708 - Caterpillar

Caterpillar: Confidential Yellow
PSP FOR EXCESSIVE AIR SIDE PLUGGING OF FOLDED CORE RADIATORS IN CERTAIN D4H AND D5H TRACTORS - PS0389 - MAILED US & CANADA, CAC O, 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.
(Revised July 1990) U-152 A-107 AU-104 E-68 O-94 1353 PS0389 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 "PS0389" as Part Number, "7755" as Group Number, and "96" as Description Code. This Revised Service Letter replaces the July 24, 1989 Service Letter. Changes have been made to the Termination Date, Affected Product, and Service Claim Allowances. Termination Date
July 31, 1991
Problem
In some applications, dust or debris can cause air side plugging of the folded core modules in certain D4H and D5H Tractors. If this plugging occurs frequently, it will result in decreased maintenance intervals and increased downtime. The Affected Product equipped with a folded core radiator or an earlier version of the multiple row module radiator can be updated to the current multiple row module radiator design. The current multiple row module radiator design has increased strength and rigidity to prevent the radiator cracking due to machine vibration.
Affected Product
Model Identification Number D4H 8PB1 - 4100