Water Pump: Testing and Inspection

DIAGNOSIS AND TESTING - WATER PUMP DIAGNOSIS
A quick flow test to determine water pump operation is check for proper heater operation. A defective pump will not circulate heated coolant through the heater hoses.

An additional flow test can by performed by the following the procedures below:

WARNING: DO NOT remove radiator cap if the cooling system is hot or under pressure.

1. Remove cooling system pressure cap.
2. Remove a small amount of coolant from the system.
3. Start the engine and warm up until thermostat opens.
4. With the thermostat open and coolant level low, visually inspect for coolant flow. If flow is present, the water pump is pumping coolant through the system.