97 Lumina Water Pump Replacement

[LikeAChampion3]

I plan on replacing the water pump in my 97 lumina sometime this week. I am looking for advice from anyone who has worked on this common 3.1 engine, specifically on the water pump. I heard that you do not need to drain radiator, only open some valve. Any help would be great, so far this site looks very helpful, thanks

[jeffcoslacker]

I don't drain anything. You won't loose much, the pump is pretty high in the system. Loosen the pulley bolts before taking the belt off. A quick snap of the wrench will break them loose. The belt will usually keep the pulley from turning just enough to break them. If not, you can push on the top of the belt to tighten it's grip a little, and that'll usually do it.

Replacing the pump is very simple, with the pulley off it is totally self-explanatory. Make sure the gasket surfaces are clean and you torque the bolts evenly. Don't get real aggressive with a scraper, that casting is aluminum and will scratch/chunk easy.

The most critical part of the job is getting the system bled correctly after you are done. That's where it goes wrong sometimes. You'll want to open the bleeder screws (one above the pump at the top of the pipe, the other near the thermostat) and fill the radiator until coolant is coming from both.

Then close the bleeders, cap the radiator and start it up. Let it run about fifteen minutes while you watch the temp gauge. Have the heater control on full heat too (just the temp selector, not the blower). Once it is showing a normal temp on the gauge shut the motor off, let it sit about ten minutes and carefully remove the radiator cap.

Open the bleeders once again and top off the system until coolant flows from them. Cap the radiator and go for a drive, watching the gauge. If it spikes high or the heat from the heater isn't consistant, you've still got air in there. Bleed it until it doesn't have any more problems.

Most of these bleed pretty easily. Usually they are fine after the first top-off after running it.

[Longknocker]

Originally Posted by jeffcoslacker

I don't drain anything. You won't loose much, the pump is pretty high in the system. Loosen the pulley bolts before taking the belt off. A quick snap of the wrench will break them loose. The belt will usually keep the pulley from turning just enough to break them. If not, you can push on the top of the belt to tighten it's grip a little, and that'll usually do it.

Replacing the pump is very simple, with the pulley off it is totally self-explanatory. Make sure the gasket surfaces are clean and you torque the bolts evenly. Don't get real aggressive with a scraper, that casting is aluminum and will scratch/chunk easy.

The most critical part of the job is getting the system bled correctly after you are done. That's where it goes wrong sometimes. You'll want to open the bleeder screws (one above the pump at the top of the pipe, the other near the thermostat) and fill the radiator until coolant is coming from both.

Then close the bleeders, cap the radiator and start it up. Let it run about fifteen minutes while you watch the temp gauge. Have the heater control on full heat too (just the temp selector, not the blower). Once it is showing a normal temp on the gauge shut the motor off, let it sit about ten minutes and carefully remove the radiator cap.

Open the bleeders once again and top off the system until coolant flows from them. Cap the radiator and go for a drive, watching the gauge. If it spikes high or the heat from the heater isn't consistant, you've still got air in there. Bleed it until it doesn't have any more problems.

Most of these bleed pretty easily. Usually they are fine after the first top-off after running it.

It took me about 20 minutes to replace mine on my 95.
I could not believe how easy it really was.
And i never drained anything, you might drip a small amount of water for a minute but nothing too bad.

[LikeAChampion3]

Thanks for the help...it was as easy as you said...but at this point it is kind of irrelevant. The dealer who diagnosed the grinding noise in my engine as the water pump was wrong. The current water pump is clean and spins flawlessly...its the A/C compressor that is the problem. I rotate that pulley and it scrapes and moves and what not. I will start a new thread on fixing that now .....Thanks for the help though!