0432698 JOHNSON CARBURETOR ASSEMBLY

Do not operate or work on this product unless you have read and understood the instruction and warnings in the relevant Operation and Maintenance Manuals and relevant service literature. Failure to follow the instructions or heed the warnings could result in injury or death. Proper care is your responsibility.
New publication being created to extend the water pump operation and troubleshooting to the engine models captured in this project, thus avoid the water pumps to be misdiagnosed in the field as leaking coolant.The following information applies to the part numbers listed in Table 1, and the pumps fitted across C3.3, C4.4, and C7.1 generator sets and engines.
Table 1
Part Number Part Name
355-2252 Water Pump Gp
354-1672 Water Pump Gp
354-4754 Water Pump Gp Water Pump Operation
The water pump contains a rotary seal. The engine coolant is used to lubricate the rotary seal and maintain an adequate sealing film to reduce generation of heat. During normal operation, a small amount of coolant and vapor will pass over the seal into a chamber within the pump. The chamber allows the coolant to evaporate through the weep hole and the vent holes in the pump.In some ambient conditions and operating conditions, not all the liquid will evaporate. In this situation, the liquid may be expelled through the weep hole. A small loss of coolant from the weep hole does not necessarily indicate a fault in the pump. A small loss is one drop of coolant within 10 seconds.The rotary seal within the pump can become compromised by debris between the seal faces. Usually, the seal will expel the debris within 30 hours of operation. During this period, there may be a significant loss of coolant through the weep hole.The seal may be damaged if there is not enough coolant flow around the seal. In this situation, the leak rate from the weep hole will be greater than one drop in 10 seconds.Water Pump Troubleshooting
Before installing a replacement water pump, perform the following procedure:
If a coolant leak is suspected near the water pump, determine if the leak is a new event.
Remove any coolant stains from the water pump and on the front of the engine.
Check the coolant level. Refer to Operation and Maintenance Manual, Cooling System Coolant Level - Check.
Monitor the area around the water pump regularly for signs of a coolant leak.
Monitor the leak rate from the weep hole in the water pump. If the leak rate is greater than one drop in 10 seconds or if the leak does not stop after 30 hours of operation, install a replacement water pump. Refer to Operation and Maintenance Manual, Cooling System Coolant - Change.
Before returning the engine to service, check for the following possible causes of insufficient coolant flow to the water pump seal:
Low coolant level. Refer to Operation and Maintenance Manual, Cooling System Coolant - Change.
Maintenance Interval Schedule adherence. Refer to Operation and Maintenance Manual, Maintenance Interval Schedule.
Air in the cooling system that was not purged during fill. Refer to Operation and Maintenance Manual, Cooling System Coolant - Change.
Leaks in the cooling system. Refer to Systems Operation, Testing and Adjusting, Cooling System - Inspect
High coolant temperature. For electronically controlled engines, refer to Troubleshooting, Coolant Temperature Is Too High. For mechanical engines, refer to Systems Operation, Testing and Adjusting, Troubleshooting.