GM Water pump neck

Beerj · Mar 18, 2016

I've got a press-in fitting for the water pump outlet. Should I put some sort of silicone sealant on it before I press it in? It's gonna be a pretty tight fit, like 10 thousandths at room temp. I plan on freezing the fitting and heating the pump to keep as much material there as possible.

85toyo · Mar 18, 2016

I hope you have better luck than I did. I couldn't get the water pump to sit flat on the press and it got in there crooked. Never could get it straightened out. Wouldn't go in any further or come out. Just cut it out of the pump last night. Reckon I'm going to order a weld on fitting and take it to a buddy.

Beerj · Mar 18, 2016

Damn, not the answer I was expecting. Do you know which part # you got? I remember them having 2 different sizes.

85toyo · Mar 18, 2016

Beerj · Mar 18, 2016

That may be your issue.
Here's the description for the one you posted. The bold part is important.

patooyee · Mar 18, 2016

You probably already know this but the stock water neck has some sort of glue / epoxy.

pholmann · Mar 18, 2016

Use some green lock-title bearing set. You'll have to buy another one if the water pump goes bad but it shouldn't come out or leak.

85toyo · Mar 18, 2016

Beerj said:
That may be your issue.
Here's the description for the one you posted. The bold part is important.

Damn I got screwed on that haha. I ordered it from Kryptonite Kustoms and they had one for car pumps and one for truck pumps with no description. Didn't even say it was a CBM and they charged me $50 :gay:

Kinda my fault but google wouldn't find another source at the time.

Beerj · Mar 18, 2016

patooyee said:
You probably already know this but the stock water neck has some sort of glue / epoxy.

Yeah, I saw that. Actually if it wasn't for that I probably would've just went in dry.

pholmann said:
Use some green lock-title bearing set. You'll have to buy another one if the water pump goes bad but it shouldn't come out or leak.

Cool, I'll see if I can find some. Kinda pains me to keep modifying stock parts since they'll need done again if they get replaced but this one hopefully won't be too bad.

85toyo said:
Damn I got screwed on that haha. I ordered it from Kryptonite Kustoms and they had one for car pumps and one for truck pumps with no description. Didn't even say it was a CBM and they charged me $50 Kinda my fault but google wouldn't find another source at the time.

Lol. Someone had a link to kryptonite kustoms on here a little while ago. Once I daw they carried CBM products I knew ebay would be cheaper. Hopefully I can get this together easily.

85toyo · Mar 19, 2016

How is the fit on yours?

Beerj · Mar 20, 2016

I haven't pressed it in yet. Still trying to locate the magical green loctite locally. As soon as I get some free time I'll pull the pump and clean up the glue residue from the stock neck. There appears to be about 10 thousandths interference. I think it dropped to about 7 after I froze the bung. But right now it doesn't drop in at all by hand.

pholmann · Mar 20, 2016

You could probably use some pipe dope too.

Beerj · Mar 20, 2016

Pipe dope I have. I even tossed around the idea of some 2 part epoxy. Honesty, I'm more worried about leaks than keeping it in there. It's gonna be so tight I don't see it going anywhere.

pholmann · Mar 20, 2016

Pipe dope or epoxy should work then

Beerj · Mar 20, 2016

Roger that! Once the boy goes down for a nap this afternoon I'll see if I can cram it together.

jccarter1 · Mar 20, 2016

That seems a little to much on that press fit.... Rule of thumb is normally .001 per inch in diameter give or take depending on material so you might want to look into before you start and get it stuck and have to ruin it or it might go in no problem haha

pholmann · Mar 20, 2016

You can always get a little hone to take some out of the water pump if you don't have access to a lathe to take it off the fitting.

Beerj · Mar 20, 2016

jccarter1 said:
That seems a little to much on that press fit.... Rule of

jccarter1 said:

That seems a little to much on that press fit.... Rule of thumb is normally .001 per inch in diameter give or take depending on material so you might want to look into before you start and get it stuck and have to ruin it or it might go in no problem haha

Click to expand...

pholmann said:

You can always get a little hone to take some out of the water pump if you don't have access to a lathe to take it off the fitting.

Click to expand...

Man, wish I would've checked this thread again before I started.

Figured I'd clean it up first.

I got the works situated on the press nice an square, dabbed some dope and went at it. It was sliding right in no problem about half way and then pop!
:'(