amphicar770

I guess I spoke to soon about GM making things idiot proof.

Tonight I finished installing new Gates water pump (made in USA), I Got everything bolted back together with new hoses, new clamps, etc.

Started filling the radiator when I noticed water (engine not running). Couldn't quite figure out source as it is dripping down the oil pan. After shining the light around for a bit, it appears to be from the pump, probably the gasket, just above the lower hose outlet.

What a pain in the ****. I will need to again remove the fan, other bits, probably the pump to see what is going on. Maybe I will discover a missing or loose bolt although I suspect the gasket got bodged up during install.

I did treat gasket with permatex aviation form-a-gasket sealer on the paper gasket which usually makes everything 100% leak proof. I did not use thread sealer on the bolts which I probably should have (although leaking past bolts usually only happens with a hot engine). Perhaps I can first just remove and replace each bolt with some thread sealer?

Just wondering if there is anything else I should check or may have missed. Any suggestions on how to check pump for leaks before reinstalling everything?

Thanks,

Mike

1970cs

Did you get all of the old gasket material off the mounting surface?

Pat

amphicar770

Yes, it was very clean, even used some emory cloth to get it nice an smooth.

Given the amount of leaking (steady trickle) when cold and not running, I am pretty certain that the gasket must have gotten bodged up, else I will have a "doh" moment when I find a bolt not tightened at all.

Still, appreciate any other theories or ideas.

MDchanic

You probably used the wrong gasket. Usually there are several with a kit, and only one is the right one. There is usually another one that looks right, but isn't.

Once you get it off, hold up all of the gaskets very carefully against the pump, and you will probably see that there is a tiny space at the point where yours is leaking.

- Eric

rjohnson442

Once you get the pump back on AND let the sealant dry you can pressure test it for leaks before you fill with fluid. Also you can listen for leaks this way and use plumbers bubbles on any suspected leaks and pin point them quickly.

MDchanic

... Also, fill with water first, because it's much less annoying when it leaks all over the engine and the floor.

- Eric

amphicar770

Thanks. I did match up the provided gasket with the imprint of the old one and they appear to match. Only difference was a very slight mismatch near what I think is a weep hole. The one in the catalogs for AC equipped cars does look different but matches neither the old/new pump or the imprinted pattern. In one other catalog I see a note that the non-AC pump gasket (shich I have) is also for oldsmobile engines so perhaps Olds and Chevy 350 SB were a bit different.

Anyway, new Felpro gasket will be here this afternoon. Hopefully when I pull the pump (again) the problem is obvious.

amphicar770

I will definitely do that. Losing $60 worth of BeCool coolant was no fun!

MDchanic

That's the spot, if I recall.





Like, perhaps they are completely different engines with absolutely no parts interchangeability of any kind, except for the cap, rotor, points, and condenser, and maybe the air cleaner element?



If you used a SBC gasket on an Olds engine, I could see the potential for problems (especially since the SBC uses 2 gaskets).

- Eric

droldsmorland

A practice which works well for me is; I apply gasket spray adhesive to the pump side of the gasket and glue it to the pump. Then apply a thin coat of RTV to the engine side of said gasket. This serves two purposes. One it keeps the gasket from squirmming out and two it makes the next pump change easier as the gasket comes off with the pump

Octania

Slight shape difference at that extra hole is the chief suspect.
Make sure gasket matches pump shape. There are 3 different types.
Damaged gasket 2nd most likely

5/16 bolts are in blind holes, cannot leak.
1/4 screws are into crankcase at bottom and air at top. Slight bit of sealer on lower ones cannot hurt.

amphicar770

Got the pump back off. Gasket definitely seems a bit crunched / torn at screw hole near where leak appears to originate. Picking up new gasket this afternoon. Will keep you all posted. Thanks again.

1970cs

The last few pumps that I have done, I just used gasket eliminator on the surfaces and pitched the gaskets. As long as the surface is dry and oil free it will work!

Pat

amphicar770

Success!

Put in the new gasket. Used Permatex Indian gasket shellac and some thread sealer. More important, I could tell that the fit of the new gasket was more precise than the one that came with the pump.

Anyway, all is leak free and tight. Filled it with H2O, brought her up to operating temp and all good.

Looks like I am ready to enjoy the rest of summer. New water pump, BeCool original style radiator with aluminum core, etc. I also redid the AC system with a new Pro6Ten compressor, new hoses and related components. BTW, the Pro6Ten, while not original looking, is an easy direct fit and is much less of a horsepower hog than the A6. I was impressed with how quickly it pulled in 4.5 lbs of R12 (you do have to change out the oil that comes with the compressor if changing to R12). Still need to test it on a really hot day but seems like a winner.

Thanks for the ideas.

Mike