PISTON 3G8138 - Caterpillar

All 3500 Series EnginesReference: Engine News, December 15, 1982, Page 11. The article, "Removal of Water Pump Impeller" tells how to remove the impellers when a retaining compound has been used.Description of Change: New water pump groups are now used on all 3500 Series Engines. The new water pump groups have larger diameter shafts and impellers with a larger hub. This permits use of a self-locking nut with 5/8" threads. A higher torque is also used for the nut. Formerly, two types of water pumps were used. There was no difference in the part numbers of the two types of water pumps. Both types of water pumps used 7/16" diameter bolts to hold the impellers on the shaft. The Type 2 water pump used a retaining compound on the taper of water pump shaft. The Type 1 water pump did not use any retaining compound.
Adaptable To: The new and former parts are shown in Chart A. The new parts, which must be used together, are direct replacements for the former parts. The new parts and Type 1 and Type 2 water pumps are in effect as shown in Chart B. Before a Type 1 or Type 2 water pump is disassembled, see the reference article. If a Type 1 or Type 2 water pump on a 3516 Engine is disassembled for any reason, our recommendation is to install the new parts.
When a Type 1 or Type 2 water pump or a 3508 or 3512 Engine is disassembled, the impeller and shaft can be used again, if they are in good condition. Do not use the former impeller with the new shaft.