water pump electric

Waterpump Replacement

RoGuE

Tomorrow I'm going to be changing out the waterpump on my dad's 2002 Suburban (5.3L 2wd). I don't believe it's leaking out of the weep hole, but rather the gaskets which seems to be really common, but with 129k miles, I guess changing out the pump makes sense. With it being replaced, I'll also change the serpentine and A/C belt (which looks horrible), along with the thermostat possibly.

A few questions I have are:

-What is the correct size for the A/C and serpentine belt? I see 93" and 92.3" for the serpentine...Also, is Dayco a good brand?

-I'll be changing the pump out with a new GMB unit from Advance since it has the lifetime warranty, and it is also only $76 after the online promo code...Any thoughts?

-Is changing the thermostat necessary? It's shown no problems.

-I'll be buying better Fel-Pro gaskets than what the pump might come with, is putting a thin layer of waterpump specific RTV on the outside edge of it a good idea?

Thanks for any help!

mdjordan2004

I just did the same thing on my 2005 crew cab a few months ago. It was not the water pump it was the crappy gaskets. Mine was leaking on the pasg side. With 125k I went ahead and replaced the water pump with a Bosch pump off amazon for about $80.00. I did come with a better gasket that stock but I still used RTV on both sides of the gasket (helps hold them in place when putting the pump on). I also replaced my belts from Autozone but don't remember the size or brand.

As for the thermostat I replaced that also. I was already in there and it only cost $10-$15 just for safety sake (with my luck if I didn't it would go bad the next week) and when you get done making a giant mess with all the coolant you will see why. I put RTV on that gasket also. I also replaced all the coolant (why not at this point) takes a little over 2 gallons.

A few extra tips. Take the plastic protective cover off the bottom that runs from in front of the the radiator to the skid plate (if you have them) you will see what I mean when you get there. That being removed will let the fluid from when you undo all the hoses, not get trapped there and into you drip pan. To get the holes in the block dry as possible I used my air compressor to blow as much fluid out of the block as possible. Filling the system back up takes a little time, turn your heat on high so make sure you get all the air out of the system.

Almost forgot, go ahead and replace the bottom radiator hose. It is pretty cheep and is another one of those things that while you are there do it now so you won't have to make that mess again anytime soon. I forgot to do mine and regretted it when I got everything apart.

Hope this helps and good luck.

rdnkcpa

Be sure and clean up the bolt threads before you put the new pump on. 10 seconds with a wire brush should do the trick. Don't over torque the bolts, I think the torque setting is 22 foot LBS, consult a manual to be sure.

I also replaced both idler pulleys. It was amazing in the noise difference. If you are doing the main serpentine belt, you should do the A/C belt as well. If it breaks you will have to remove the main serpentine belt to replace it anyway. IIRC the A/C belt is not too expensive.

I went with A/C Delco direct OEM replacement on the waterpump, so there was no problem at all. The first factory pump went 120k without a problem, I expect the replacement to go just as far.

mdjordan2004

Ditto on all the things the other said. I also used air to dry holes. By this time I guess it is already done, hope it went well. I also used an Autozone water pump, I think mine went out around the same milage 125k or so, at 170k now without any problems. My pump was good it was the passenger side gasket was the problem as well. RTV works grate to hold things in place and is a little backup just in case. Did the thermostat also like others side while you are in there might as well.

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Knotsure

Probably already done this job, but I believe when you change the water pump you have to change the thermostat. At least that was the case on my 2006 sierra 4.8l.

Gurrzt

Make sure the new water pump pulley is the same size as the one you are removing, other wise the stock belt size is a moot point.

gmtech4

Also replace the a/c belt tensioner assembly , they poop the bed often