MANIFOLD-EXHAUST 1666338 - Caterpillar

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 "PS5666" as the Part Number and "7755" as the Group Number. Use "96" as the Warranty Claim Description Code and use "Z" as the SIMS Description Code.
This Revised Service Letter replaces the July 26, 1999 Service Letter. Changes have been made to the Affected Product.
Termination Date
July 31, 2000Problem
Lubrication from the bearings of the heater/air conditioner blower may contaminate the blower motor of certain M312, M315, M318, and M320 Wheeled Excavators. A short circuit within the motor may then cause frequent failure of either the main heater/air conditioner circuit fuse or the resistor temperature fuse at the blower motor. The replacement blower group has sealed blower bearings which retain lubricant and prevent contamination of the motor.
The complete motor has to be replaced to solve the problem. Replacing only the 122-2373 Resistor will not solve the problem.
Only blower motors produced between June 1997 and July 1998 are affected by this problem. If the plastic bracket holding the blower motor in its housing is removed, a decal states the electrical motor's production date. Only motors produced between U16 (16th week of 97) and V16 (16th week of 98) may have the above mentioned problem.
Affected Product
Model & Identification Number
M312 (6TL1-789)
M315 (7ML1-1417)
M318 (8AL1-2004 6ES1-237 8SS1-461 )
M320 (6WL1-381 9PS1-268 )
Parts Needed
1 - 1737421 BLOWER GPAction Required
1. Swing the machine upper frame 30 degrees to the left.2. Remove the bottom plastic cover below the cab.3. Remove the bottom plate (A) from the housing of the heater\air conditioner group through removal of 6 screws (a) at the bottom and 5 screws (b) at the front. Reference Illustration below.4. Remove the two M6 bolts (c), located each side (left and right) of the housing.5. Rotate the plate (B) to the front as far as possible for easy access to the blower group.6. Rotate the plate (B) to the front as far as possible for easy access to the blower group.7. Remove the 5 screws (d) holding the blower group to its fastening plate.8. Following the above procedure in the reverse order, install the new blower motor.
Illustration 1Service Claim Allowances
This is a 2-hour job.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.