How to Know When a Water Pump Is Going Bad on a Chevy Tahoeby Gregory Crews
The Chevrolet Tahoe has a water and antifreeze-based coolant system. The water pump is an integral part of the truck's coolant system. The purpose of the water pump is to push coolant through the radiator and through the engine. The first sign of a faulty water pump is coolant gathering under the engine when the truck has been sitting overnight. The smell of coolant also will dominate the interior of the truck when operating. If you notice these symptoms, watch the temperature gauge to ensure the truck does not overheat.
Examining the Water Pump
Allow the truck to run for five minutes. The coolant system needs to build pressure. Turn the truck off once it is warmed up.
Open the hood for access to the engine compartment. Locate the water pump in the middle of the front of the engine.
Inspect under the water pump for any coolant leaking out. Signs of a faulty water pump will occur when coolant is leaking out of the vent hole or weep hole.
Notice the dripping coming out of the water pump. The leak will be a solid stream of coolant.
Using a Pressure Tester
Purchase or rent a pressure tester from an automotive parts store. The pressure tester is designed to apply pressure to the coolant system and push coolant where it is leaking.
Unscrew the pressure cap from the radiator by hand. Apply the end of the pressure tester to where the pressure cap came off, at the top of the radiator. Look at the top of the radiator pressure cap and remember the number imprinted. The number will indicate the pounds of pressure needed to test the radiator.
Pump the pressure tester to the number indicated on the cap. Observe the pressure to see if it drops. If the pressure is dropping, attempt to locate where the coolant is being pushed out. If the pressure is pushing coolant out of the water pump, this indicates the water pump is starting to break down and needs to be replaced.
Slowly twist the tester off the radiator to break the pressure built by the tester.
- Some automotive parts store have a rental program that allow you to rent instead of purchase the pressure tester.
- Use caution when working around the coolant system. The coolant will be hot and under pressure; it needs to managed with great care to prevent injury.
Items you will need
- Radiator pressure tester
- Aa1car: Water Pump Troubleshooting Tutorial
- Aa1car: Tutorial on Coolant Systems and Radiator Pressure Testers
- "Chevrolet Silverado and GMC Sierra Haynes Repair Manual for 1999 thru 2006 Full-size Light-duty Gasoline Engine Models. Includes 2000 thru 2006 Suburban, Tahoe, Yukon, Yukon XL, Sierra Denali. 2001 thru 2006 Yukon Denali. 2002 thru 2006 Chevrolet Avalanche. 2007 Chevrolet Silverado Classic and 2007 GMC Sierra Classic and Sierra Denali Classic."; John Haynes; 2007
- temperature dial image by Robert Kelly from Fotolia.com