EhWard

Quick question :

What # rad cap should I be using on my 1964 Corvette with Vintage Air A/C?

The current one on my surge tank is a 13# but from what I’ve read, those are for non-A/C cars. Considering the A/C unit was installed after the fact, should I replace it with a 15# cap?

There seems to be a very slight “hissing” coming from the current cap when I return from a cruise.

What do you all think?

Thanks in advance.
Cheers!

65-StingRay

It sounds like the cap may be failing at this point. Going to the 15 lb cap should be no problem. I'd have to check my reference manuals for the exact number. But someone will chime in quicker with an answer than me going to the garage and finding it.
65-StingRay

tbarb

Try the RC-26 cap, this is a 15 pound cap, I would keep your 307-13 cap and have it tested. The leaking rubber in the cap can be replaced and you may even want to start there providing it's the cap and the engine is not overheating.

sunflower 1972

62beater

W would a local radiator shop test a cap for you? And how do you replace the leaking rubber? Thx!

62beater

Anyone have a lead on how to restore the leaking rubber on a radiator cap? Thanks for the help the Corvette corporate knowledge here on the forum is greatly appreciated!

sunflower 1972

If really want to use your old cap, I would buy a new radiator cap, remove the new gasket and install it on my old cap.