GM Genuine Parts 12703898 Engine Water Pump

Perfect fit for my Silverado. Clean the block mating surfaces very well. It’s easier to purchase a new thermostat and housing because my origional would not have fit. I only bought new AC Delco tensioner, belt, pump, thermostat and housing. All worked perfect together with no leaks.Had trouble with fan clutch. Used pipe wrench on the old pulley and adjustable wrench with breaker bar to remove with the old unit sitting on the tail gate.

I recently had a radiator that had a crack and I had to replace it in the middle of nowhere to get back home. Unfortunately I got the wrong thermostat from the auto parts store, so I knew I was going to have to go back and change it. Then I had a heater hose connector go bad on me and then I figured, I'm just going to go ahead and replace everything since I'm going to have to go back into it. The water pump I had was working fine, but I have 250,000 miles on my truck and since I'm going to be replacing the thermostat, I'm just going to go ahead and do it. I drive over the mountains a lot and this is relatively cheap insurance. I went ahead and got the felpro gaskets to go along with it, the ones that came in the box are probably just fine, but it's peace of mind knowing the quality of everything going in there. I also know that there was a lot of questions about the fitment of the thermostat housing because of a change in production. I picked up an AC Delco 15-11057 and there was no fitment issues. I was a pretty simple job, It didn't take long even though I took my time.

This genuine GM water pump is terrific. One thing you will want to be aware of is that not all designs of thermostats/housings will fit in this water pump. I believe the design was changed as some point. I will include two pictures so you can see the visual difference between the two. The thermostat housing that fits is the style that does not include a thermostat as a part of the housing. The thermostat housing that does not fit is a one piece housing that includes the thermostat.

The water pump was an exact match to my old one. Best thing about it is it doesn’t leak antifreeze.

Installed new pump with new gaskets started leaking so ordered another set of gaskets did not help still leaking. Bought new pump from GM installed no problems with leaking. Now Amazon says can’t return.

This water pump is a brand-new OEM replacement. It is made in Mexico and not in China like the AC Delco new replacement water pump. The fitment is good and is supplied with gaskets and new bolts for the Thermostat housing. It is recommended that an updated Thermostat housing kit be ordered along with this water pump. My vehicle is a 2003 Express with a 6.0 L V8. The Thermostat has a rubber seal on it. I recommend using a little sealant on housing to water pump since there is no gasket used. Overall, this is a good water pump!

Installed one year ago, no problems.

works great