SWITCH GP-BYPASS 3917125 - Caterpillar

3208 Engines In All ApplicationsReference: "Holes Added To Water Pump Impeller" on Page 6 of the May 17, 1982 Service Magazine.Description of Change: The reference article tells about the addition of two 6.35 mm (.250") diameter holes to water pump impellers for 3208 Engines. The two holes increase the flow of coolant around the shaft seal for longer seal service life. The article gives information for modification of existing impellers, but the part number of the new impeller was not available for release at that time. The new impeller part number is now available, and is shown in the parts chart that follows. New water pump groups and a new rebuild kit are now available for 3208 Engines. The new pump groups and kit have a new seal assembly, which uses a seal made of a carbon material. The carbon seal material will give longer service life than the phenolic (plastic) seal formerly used. In addition to the new seal, the new pump groups have the new impeller with two holes between the vanes as shown in the reference article.
The new rebuild kit is released specifically for the reconditioning of water pump groups on 3208 Engines only. The former kit also had parts for rebuilding some former design 3204 Engine water pumps, which are no longer available. The new rebuild kit has all the parts needed for pump reconditioning, including the new seal and the pump mounting gasket. The new seal can be ordered separately for addition to earlier rebuild kits, if desired. During pump reconditioning, the recommendation is to install the new seal (as part of the rebuild kit), and add the two 6.35 mm (.250") diameter holes to earlier impellers which do not have the holes. See the reference article. This will make a former pump group basically the same as the new pump group.
Adaptable As: Direct replacement, as shown in the chart.