Water Pump Replacement

[pmsmith2032]

I need to replace the radiator (leaking) on my 2005 GMC Envoy and am wondering if I should replace the water pump at the same time. The Envoy has approximately 150k miles in it and the water pump has never been replaced. There aren't any cooling problems except for it overheating once about a month ago. When it did overheat I had sat in a parking lot for 15 minutes or so with the air on, drove home for 25 minutes in stop and go traffic, and then turned it off for 15 minutes or so. After driving again for 5 minutes (low speeds under 25 MPH) it overheated. Thanks!

 

[Mooseman]

If it's original, I'd replace it as well as the t-stat and coolant temp sensor. Except for the radiator, go ACDelco all the way for reliability.

 

[pmsmith2032]

Thanks! Do I need the water pump that doesn't include mount bolts (ACDELCO252822{#89036357}) or the one that includes gaskets (ACDELCO251731{#12620226)?

 

[Mooseman]

Bolts aren't mandatory as they are reusable. I usually use RTV instead of the gasket but IIRC the original does have one so it's your choice.

 

[Tiggerr]

Original is a metal gasket I believe. Mine came with cork/paper. My experience, If you don't replace it when you have it apart It'll go out a week later lol.

 

[pmsmith2032]

Thanks guys. Is there any kind of "how to" on how to replace the radiator, water pump, t-stat and coolant temp sensor? I'm also going to be replacing the idler pulley, serpentine belt, and possibly the front struts at the same time. Everything is ordered and should be here in a few days.

 

[Mooseman]

For the radiator, I found this on the OS (would be nice if someone could do one for us here )
http://forums.trailvoy.com/showthread.php?t=81011

The rest is in our FAQ:
FAQ: Vortec 4.2L I-6

 

[Tiggerr]

Only hard part is getting the %#^=*%! fan off! Lol

 

[webdawg]

http://gmtnation.com/forums/threads/toolguy1954s-4-2-i6-water-pump-pulley-holder.14337/#post-527748

 

[Mooseman]

Those are no longer available.

 

[webdawg]

In your other closed post you said they where not avail?

Did you contact him? The guy has no listings but last time I had to contact him and have him make more.

 

[Sparky]

Autozone's new water pump holder tool set rental is a complete set that has several different sizes of everything. Worked OK last water pump I did.

 

[Matt]

Here's my how to on replacing the water pump: http://gmtnation.com/forums/threads/how-to-replace-the-water-pump.15639/

 

[pmsmith2032]

Thanks all. How long should I budget to replace radiator, water pump, t-stat, hoses and coolant temp sensor? Should I add some sore of additive to coolant beforehand to aid in flushing?

 

[Mooseman]

Depending on your abilities, I'd say 3 to 4 hours.

 

[Matt]

No need to add anything to the coolant beforehand, but you might want to get some Prestone Radiator Flush and use that as per the directions, it's pretty good.

 

[pmsmith2032]

Thanks guys! How many gallons of coolant should I buy?

 

[Mooseman]

1 gal. of pure Dexcool and 1 gal. of distilled water should do. Mix 50/50.

 

[snoozer]

Here's my how to on replacing the water pump: http://gmtnation.com/forums/threads/how-to-replace-the-water-pump.15639/

Thanks for the link. Makes me wonder why the shop who put new pump & fan clutch on said it was a 3.5 hour job. Sure doesn't look like it would take that long.
Think I got screwed, along with fighting with them to replace the defective fan clutch they installed. Running thermal clutch now, much better.