POWER SUPPLY 1C3939 - Caterpillar

Introduction
This instruction gives the procedure for inspecting and installing water pump seal groups.Correct inspection and installation procedures can help to prevent unneeded replacement of engine water pump components.Use the chart that follows to find the correct seal group and installation tool for a given engine. Reference: Operation and Maintenance Guide, Parts Book, Service Manual.Installation Procedure
1. Remove and disassemble the water pump as shown in the Service Manual. 2. Remove the old seals, and use steel wool to clean the shaft. Some corrosion and/or deposits on pump shaft (1), where carbon seal assembly (2) and ring (3) meet, is normal and does not require replacement of shaft (1).A polished area on water pump shaft (1) indicates that carbon seal assembly (2) has been spinning on shaft (1). Use 240 grit emery cloth to clean the area before installing a new seal assembly.3. Use a micrometer to measure pump shaft (1) at location (A). For the correct fit of carbon seal assembly (2), the shaft diameter must be:* 19.10 mm (0.752") 0.05 mm (0.002") for 3300 and 3400 Series Engines.* 25.45 mm (1.002") 0.05 mm (0.002") for 6.25" Bore Vee Engines.4. Install a new oil seal (4) in housing (5) as shown in the Service Manual.5. Install shaft (1) and bearing as shown in the Service Manual. All 3400 Series Engines must have clearance between the water pump seal group and impeller counterbore (B). If there is interference, machine impeller counterbore (B) diameter to 34.30 mm (1.350") 0.051 mm (0.0020") or install a new impeller.6. Use 6V1541 Quick Cure Primer to clean shaft (1) and counterbore (C) in pump housing (5).7. Use the non-counterbored end of installation tool (6), and install ring (3) and the seal in housing (5). See the chart on the opposite page for the correct installation tool. 8. Remove the spring, and dip carbon seal assembly (2) in clean water. Use clean water only to reduce the friction between the seal rubber and shaft (1).Do not get any oil or grease on the face of the seal.9. Use the counterbored end of installation tool (6), and press (by hand) seal assembly (2) onto shaft (1) until the carbon seal face makes light contact with the face on ring (3). See the chart on the opposite page for the correct installation tool.The carbon seal assembly must rotate with the water pump shaft.10. Install the carbon seal assembly spring.11. Complete the assembly and installation of the water pump as shown in the Service Manual.After the assembly is complete, get the engine ready for use as shown in the Operation and Maintenance Guide.