Usage:
NOTE: 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.
NOTE: This Revised Service Letter replaces the July 10, 1996 Service Letter. Changes have been made to the Action Required.
Termination Date
October 31, 1996Problem
The plastic impeller used on 3306 water pumps will fail causing the engine water temperature to increase and a loss of coolant flow through the heater core.
Action Required
1. Remove the following water pumps from Parts Stock:
Look into the coolant outlet at the top of the pump.The top can be identified by its divided passage and two " bolt holes.If the impeller inside the pump is gray, return the pump to Parts Stock.If the pump has a brown plastic impeller, replace the impeller.
2. Purchase the 7N5910 Impeller required to update the water pump.
3. Remove the two cover bolts and cover to gain access to the impeller retaining bolt.
4. Remove the impeller retaining bolt.
5. Use two screwdrivers to pry the impeller off. If the plastic portion of the impeller breaks away from the metallic hub at the center, the hub can be removed with a puller.
6. When the 4W9645 Impeller and hub have been removed, install the 7N5910 Impeller by placing it on the taper shaft and tightening the impeller retaining bolt to a torque of 28 lb. ft. (38 N·m). DO NOT TAP ON THE IMPELLER, THIS WILL FRACTURE THE SHAFT SEAL.
7. Assemble the pump and return to Parts Stock.
NOTE: TEPS/MEPS dealers are reimbursed for recalled Parts Stock by returning the affected Parts Stock to their administering Caterpillar dealer for replacement.
Service Claim Allowances
Submit one claim for all Plastic Impellers removed from Parts Stock.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.