This water thermostat controls the flow of engine coolant to regulate the operating temperature of the host tractor or combine. It sits in the engine cooling circuit between the cylinder head outlet and the radiator inlet. When the engine is cold, the thermostat remains closed, forcing coolant to circulate within the block for faster warm-up. As coolant temperature rises, the wax element expands, opening the valve to allow flow to the radiator. A thermostat that sticks open delays warm-up and reduces heater performance; one that sticks closed causes overheating. The AGCO-manufactured unit matches the original housing bore and seal geometry, so the bypass circuit opens and closes at the correct temperature without leakage. On reinstallation, clean the housing mating surface and install a new gasket.