The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - Overheating...How do you check a water pump?

beaterC10 · 03-15-2006, 08:49 AM

You should be able to check the pump by getting the truck to operating temperature with the rad cap off. You should see a steady stream of coolant returning to the rad with the thermostat open. You should also have good heat from the heater assuming everything else is working. Lack of return flow or no heat at idle would suggest you have a bad water pump.

My experience has been that a bad water pump is most noticeable at low speeds and idle.

03-15-2006, 08:49 AM	#4
beaterC10 Senior Member Join Date: Jul 2003 Location: Indianapolis, IN Posts: 1,277	Re: Overheating...How do you check a water pump? You should be able to check the pump by getting the truck to operating temperature with the rad cap off. You should see a steady stream of coolant returning to the rad with the thermostat open. You should also have good heat from the heater assuming everything else is working. Lack of return flow or no heat at idle would suggest you have a bad water pump. My experience has been that a bad water pump is most noticeable at low speeds and idle.