It's alive!

General discussion about C3 Corvettes
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Posts: 2058
Joined: Sep 7th, 2009 5:31 pm
Tell us about your Corvette: 1971 Coupe, restoration in progress.
Location: Waterboro, Maine

Re: It's alive!

Post by MaineVette » Oct 2nd, 2016 7:12 pm

Hey guys, got the water pump figured out this weekend. I pulled it off the car and rigged it up so I could complete a pressure test on it. I capped both ends where the pump bolts to the block with some scrape steel and silicone and then attached an old radiator hose to the pump and plugged the other end of the hose with an old caulking tube. I then made a small hole in the rubber hose to insert my air wand into. Granted, it's a pretty crude setup but it worked perfectly!


My favorite part is the old caulking tube. :ROFL:

I set the air wand to 15 psi with my regulator (which I verified with a separate gauge) and pressurized the pump. Water started leaking out everywhere immediately, the gasket on the back of the pump just wasn't sealing well. I decided to remove the backing plate and the screws were barely tight at all, just a bit more than finger tight. :rolleyes: That probably didn't help things.

So, I decided to pull off the plate and install a new gasket with the addition of some black RTV as an insurance policy. The backing plate on the aluminum plate also seemed a bit thin when I pulled it off so I decided to compare it to the one on the old cast iron pump that was on the car when I bought it. The plate on the original pump was about 1/32" thicker than the one that was leaking. The thinner plate probably didn't help things either. At least both were fade of steel.

I decided to pull the plate from the old pump and installed it on the aluminum pump with a new gasket and some RTV. I tightened everything down, let the RTV cure overnight, and did a new pressure test. I'm happy to report the pump took 40 psi without leaking a drop! I didn't push it any further than that but my sense is that the problem is solved :thumbs:
Someday I'll finally be able to drive my Vette, but for now I'll just admire all the pieces... :willy:

Track my progress at The Corvette Restoration Page