STARTING MOTOR GP-AIR 7C3372 - Caterpillar

All 3500 Series Industrial, Generator Set And Vehicular EnginesDescription of Change: Several improvements have been made to the cooling system on the above engines. In the water regulator group (outlet control) a new housing assembly, valve assembly and plug are used. The new housing, which includes the valve assembly, has an orifice which will permit a small amount of coolant to bypass the regulators. This will help prevent cavitation at the water pump. Also a drain hole and plug was added to the housing. This will permit the housing to be drained before the engine is put into storage. The new valve assembly in the housing is used to let air out of the system. The valve assembly is plastic and is used in place of the former steel ball and ferrule. In some applications it was possible for the former ball to stay in the open position. As a result, the water temperature was too low.
In the water lines group (bypass) a new housing and several other new parts are used. The new housing has less volume so less air will be trapped (held) in it when the cooling system is filled.
New tube assemblies are used in the radiator groups. The new tube assemblies, which are used on the inlet side of the radiator, have orifice plates with smaller openings in them. These new tube assemblies can be used along with the new housing in the water lines group to prevent cavitation at the water pump.
Adaptable To: The new and former parts are shown in Chart A. The new parts are in effect as shown in Chart B.