Thickness of water pump gasket??

[ShawnZR-1]

Ok, so I put the new water pump on and torque the bolts down. Go to spin the pulley and it won't budge at all!

So, I take it all back apart and put the old and new side by side on the bench. The impeller is within 1/32" but the gasket thickness between what was on there and what was included with the new pump is 1/16" thinner on the new one!

I pulled a spare gasket down and it's just a bit thicker than the new one but still thinner than the original.

Anyone know what the original ACDelco gasket's thickness is?

[ShawnZR-1]

Are those ACDelco gaskets?

It looks like the one on there is 3/32" (compressed). .09" is twice the thickness of yours.

[Scrrem]

I'm getting ready to do the water pump on mine. When I get home tonight I will have to measure the gasket that came in the box.

Rich

[ShawnZR-1]

Scrrem, is your pump an AC Delco also?

[Scrrem]

Originally Posted by ShawnZR-1

Scrrem, is your pump an AC Delco also?

Not sure. It's a rebuilt unit, is there a way to distinguish an AC Delco unit?
Rich

[A26B]

Originally Posted by ShawnZR-1

.... So, I take it all back apart and put the old and new side by side on the bench. The impeller is within 1/32" .........

You mentioned that this is a rebuilt pump. What dimension are you referring to that is within 1/32"?

Here are dimensions taken from a used, OEM pump. Measure yours & maybe we can locate the problem. With rebuilt pumps, there are an array of possibilities that could cause the pump to bind on installation. Once rebuilt, it no longer matters if it says AC Delco on the pump.

A. diameter of the impeller : 3.857"
B. height from pump flange to back of the impeller : 0.175"
D. height of impeller hub from back of impeller : 0.160"
E. used oem pump gasket : 0.044" current thickness (note, new gaskets will compress when installed and have some "rebound" when removed) est uncompressed thickness, 0.049". Compression & rebound depends on the composition of the gasket material.

Jerry

[A26B]

Originally Posted by Dynomite

Jerry....my micrometer does work perfectly I guess
He said his original gasket was .093 so that confuses me.

Yes, 0.093" is probably erroneous. Used gaskets usually have a portion that is outside the parts face and doesn't compress and swells up. If you don't isolate that portion when measuring, you get a bad reading.

I think the problem is going to be in the rebuilt pump.

[ShawnZR-1]

My .093" is as close as I could measure because it's still stuck to the old pump. I can't mic it. I can't remove the gasket because it just deteriorates in my hand.

I'll get more accurate measurements tonight when I get back home.

I appreciate all the help guys! I just want to isolate where the problem is. By the sounds of Dynomite's dry fit of his pump, it is looking like mine is way out of tolerance.

[phrogs]

does your pump spin freely in your hand?

Im sure it does but when you installed it the propeller is binding against the front engine cover so thats a problem, perhaps it wasnt pressed all the way on and is sticking out jut enough. Its a tight fit in there anyway.

[ShawnZR-1]

It does spin in my hand, just when it's torqued to the engine, it seizes up. If I loosen the bolts and spin it, it scrapes against the block. Something ain't right with it!