choice of two water pumps ?

[jaywish]

I went to the flap and asked for a domestic made water pump for the wagon. After they laughed for awhile, they looked up the part and asked me which impeller size I have. I took both pumos home so I will have the correct pump and return the incorrect.

My old pump is not out yet but it is now visable. The one with the smaller impeller has an aluminum pump body and matches the body in the car. The one with the larger impeller has a cast iron body and it appears that it would bolt up, but it does have two extra holes in the body. My phone camera decided to stop working today so no pics.

On the surface of things it sounds like it might be nice to have a bigger impeller but It does weigh more and has extra holes. So what is this about?

Thanks,
Jay

[gadget73]

They are interchangeable. Just put the one with the iron body on, its the heavy duty pump. You'll need to add the extra bolts but its a standard 5/16" NC by some length thats about 2". The timing cover should already be tapped, though its very probable that the holes will need to be cleaned out first.

[marquisman]

here is some food for thought. if a parts guy laughs at you, run far away from the place. people like that are usally not serious about doing business.

[jaywish]

They are actually pretty good and I have been buying from them for many years. They treat me right on prices. It is just that the counter guys have given up on made in usa as the buyers buy cheap and that seems to be what the customers want. Also I am a bit of a pita for them as I always ask them to source usa made and it takes alot of time.

[jaywish]

I will use the iron pump. I really need to get bottoming taps one of these days.

Thanks,
Jay

[BerniniCaCO3]

On both the GMs I have, I put on the iron water pump, and on both of them, I had to grind the alternator bracket down a little bit. The iron pump is a bit wider.
No biggie, just have an angle grinder or bench grinder handy and don't be surprised when the bracket doesn't *quite* fit on!

[jaywish]

thanks for the tip

[86VickyLX]

Get the larger impeller pump. Heavy duty for the win!

[jaywish]

Tha larger pump is in. I blew a block to valve heater hose on long island. I develped a really small leak as a result. I could not find it but I could smell it. When I changed my oil yesterday I found a bit weeping out of the back of the pump.

So I changed all the hoses and thermostat as well as the pump. I had an ongoing vaccum leak and took advantage of having all the water hoses out and out of the way to find it. First I checked the can, no problem, then checked the green line to the egr. Bang the EGR leaked. I hope that was my only leak so my atc will work when I hit the gas.

Anyway I would have finished putting it together but I after the flap store closed I realized the idler pulley needs to be replaced so back to the store in the AM. Just have to do the idler, a/c belt, fan, fan shroud, alternator belt, top hose and fill her up.

I am really glad to have the help this site provides. I wanted to install the pump with the bigger impeller but you guys made the choice easy as I found out there really were no problems waiting to bite me later.

Thanks,
Jay