Chatham Engine Rebuid: Water Pump
An OEM water pump rebuild kit was sourced from Japan, and I was able to rebuild the water pump. The water pump was not configured to OEM specs with the cock intalled at the outlet?
New heater cock assembly from Eurasia: http://eurasia.cart.fc2.com/ca18/21/p-r18-s/
Routinely in a rebuild the water pump should be completely rebuilt, new bearing, new seals and rotor. I have built a spare water pumps on standby to replace in case there is a failure. The last picture is the waterpump rebiuld kit from Eurasia: http://eurasia.cart.fc2.com/ca18/222/p-r1-s/ That includes all of the necessary parts to rebuild the pump
Here I borrowed some photographs from John's site to give some further explanation to the rebuild; the basic parts, impeller, inner seal, bearing, seal and retaining clip:
The rotor is a friction fit onto the shaft. Typical failure is seized bearing or worn seal allowing water to escape into engine. Eurasia, Spread tool and Ortmann all offer water pump rebuild kits. Eurasia has the proper impeller for the s600 at time of this writing. The s800 impeller is slightly deeper and needs to be modified to work on an s600 pump housing. The two pumps are interchangable, but different depth.
The drive for the water pump, any leaking water due to a faulty seal can enter the engine compartment and contaminate the oil.
A photo of the installed impeller. The water pump casing for Chatham back from bead blasting and ready to assemble with OEM kit.
In case you damaged a bolt, the OEM fasteners to reassemble the body of the pump and for attachement are also still available from CMSnl:
An aftermarket thermostat and gasket are also available from Eurasia, Ortmann and Spread-tool