Water pump studs?

[azdesert rat]

I have a '89 W/305. The water pump needed replacing. So I pulled it. Bought a re-manufactured one at Checker/Schucks/kragen and exchanged the core. Well like a dumbass I didn't think to compare the old and the new. So now I see that the new one didn't have studs. So back to the parts store to buy studs. Then when I went to install them into the new pump.. well they don't seem to fit!

First I tried with a small pair of vice grips with cloth, as not to mess up the threads.. All I could get was about a 3/4 turn. So then I tried double nutting and that only got me about a half turn more.

To me, the threads on the studs look different than the holes in the pump. But I know that the studs can only go in one way..as the nuts only fit one end.

Should I just double nut them again and try tighten them down with force? I'm tempted.. but the last thing I need is to shear off studs..or not be able to get them in far enough to tighten the pulley and clutch.

I knew something wasn't right when it only took me about 15-20 minutes to pull the pump.. it was just to easy! haha

but I'm at a loss. Any help will greatly be appreciated!

[silicon212]

The proper studs should have fine threads at least on one side (the side that goes into the pump).

[azdesert rat]

Originally Posted by silicon212

The proper studs should have fine threads at least on one side (the side that goes into the pump).

Right. And the studs are that way. I know they can only go in one way. As the nuts only fit on one end. BTW, These are the studs I bought.
https://www.dormanproducts.com/cgi-b...tegory_list=:0

They say their for most Gm products.. But when trying to screw them into the pump, at best I can only get 1- half turns.. and thats with more force than feels right. And that leaves it about a 1/4 inch above the transition between threads.

It's just that when I try to tighten down the studs.. well it just don't feel right.. you know, likes it's trying to strip, or getting ready to snap! Something ain't right. The only thing I can think of is to see if I can find a tap of the right size.. and run it through the holes.

[j cAT]

i would go to auto salvage yard to get the hardware if this is possible.

[brcidd]

Probably your pump has metric threads and your studs are english....

[bobss396]

I agree, they should turn in by hand, at least start without a big effort. Your parts place should be saavy enough to give you the correct studs to go with the pump.

The rule of thumb when you swap pumps is: Take out the old studs and save them, take them with you to check the fit in the new pump. Lay both pumps on the counter at the parts store with the block surface down and eyeball the flange height. Also take out the heater hose fitting at home, they're a bit** to take out of a loose pump.

Bob

[azdesert rat]

I love this board!

Yeah, you guys are right, they should turn in by hand.. or at the very least should go right in with little effort!

As far as switching out studs from old to new... I thought buying new studs would be faster and easier than marring up the old ones by taking them out. I have a feeling that they wouldn't have fit anyways.


brcidd may be right about the threads on the pump being metric and the studs are SAE.. Or at least thats the way it feels when I try to tighten them down.

But yeah, Bob, you are right! I should have pulled the studs... and then seen if they would fit in the new one. But, I guarantee you they (parts store) would have told me that I need to buy the studs they have on shelf... And yeah, I guess I could/should have taken them out of the package right there and tried them... So Your 100% right!

I haven't had the time to work on it again. But I will tomorrow and the next day.

If I can find 4 bolts that fit, That would be ok? right?

Hey guys... Thanks for your help!
Billy

[silicon212]

Yes, you can use bolts in lieu of the studs. The studs are easier to work with, but the bolts work if you have patience.

Make sure the bolts are no more than 1/2" long, 5/16 diameter 24TPI.