General Information

LOCATION
The engine thermostat is located on the front of the engine (radiator side) in the thermostat housing/engine outlet connector.

GENERAL INFORMATION
The thermostat has a air bleed located in the flange and a o-ring with a locating dimple incorporated on it. There is a relief in the cylinder head for locating the air bleed. The engine cooling thermostats are wax pellet driven, reverse poppet choke type.

PURPOSE
They are designed to provide the fastest warm up possible by preventing leakage through them and to guarantee a minimum engine operating temperature of 88 - 93°C (192 - 199°F). They also automatically reach wide open so they do not restrict flow to the radiator as temperature of the coolant rises in hot weather to around 104°C (220°F). Above this temperature the coolant temperature is controlled by the radiator, fan, and ambient temperature, not the thermostat.

OPERATION
The thermostat is operated by a wax filled container (pellet) which is sealed so that when heated to a predetermined temperature. The wax expands enough to overcome the closing spring and water pump pressure, which forces the valve to open. Coolant leakage into the pellet will cause a thermostat to fail open. Do not attempt to free up a thermostat with a screwdriver.