AC cap 15#, RC-15

[Michael M.]

I need help identifying the application of two different AC caps. They both say TURN TIGHT, REMOVE SLOWLY. The difference if where the 15# and RC-15 are on the cap. One has AC on one side in a circle and 15# RC-15 on the other side in a circle. The other cap has 15# RC-15 not in a circle and Made in USA on the other side. What cars are these caps for and are they worth anything.

[Peter L.]

Re: AC cap 15#, RC-15

Michael - Without pictures I'd say from your description, the RC-15 w/ the MADE IN USA and the RC-15 15# just above that is a pre-1966 PRODUCTION years radiator pressure cap used on most GM passenger vehicles w/ C60 AC.

If the other cap with the AC and the RC-15 15# in circles has the same cover configuration w/ the larger ears, it was used from 1966 to 1972 (?). If it has a countersunk head "rivet" end on the support that holds the cap together, it's a 66 to 69 (?) application and if it has a flat top head end on the support that holds the cap together, it's a 69 (?) to 72 (?) application.

On later RC-15 radiator pressure caps the ears on the cover were smaller and the cover was Stainless steel.

As with everything, worth is dependent on the application, condition, etc and of course, on how badly someone needs it.

Pete

[John H.]

Re: AC cap 15#, RC-15

Here's the original RC-15 cap on my '69 Z/28 (February '69 build).

[Jerry B.]

Re: AC cap 15#, RC-15

hello , I have owned a e69 since oct.1970. It has a RC26?

[Sal C.]

Re: AC cap 15#, RC-15

RC26 is correct for aluminum radiators

[Michael M.]

Re: AC cap 15#, RC-15

John thanks for the picture of the AC cap. The cap I have is exactly like yours except my rivet is hollowed out. So does that mean the cap I have is for a 1966 SB or BB car.

[Peter L.]

Re: AC cap 15#, RC-15

Michael - The RC-15 is not a Corvette only radiator pressure cap. It's application was across the GM passenger car lines including Chevrolets, Corvettes, Chevelles, Corvairs (just kidding), various Buicks, Pontiacs, etc.

One application it was not for was sb & BB Corvettes with aluminum overflow tanks.

Pete

[Erv M.]

Re: AC cap 15#, RC-15

Peter,

I also have seen caps with the rivet hollowed out. Is this an original cap?

[Clark K.]

Re: AC cap 15#, RC-15

There is nothing in the 1965 JG about the cap you mentioned in your original post. A 1965 C60 (A/C) car would have an AC #RC-26. A non-A/C equipped car would have "...a cap rated at 13 psi with an AC logo and 307". So, you can rule out a 1965 Sting Ray. -Clark

[Dale S.]

Re: AC cap 15#, RC-15

Thank you Peter. Dale

[Patrick H.]

Re: AC cap 15#, RC-15

Peter,

I also have seen caps with the rivet hollowed out. Is this an original cap?

Yes. From what I can tell, the "hollowed out" rivet is 67 and earlier, the flat rivet is 69 and later. I have yet to see enough 68 data to arrive at a conclusion.

Patrick

[Jack H.]

Re: AC cap 15#, RC-15

Another small aspect of these caps that I've wondered about is the factory original treatment of their emboss. Specifically, as I've walked the scrap yards and found originals here/there, SOME have shown positive evidence of the embossed depressions containing black 'highlight' paint...

[Michael M.]

Re: AC cap 15#, RC-15

Patrick I hoped you or Tony would chime in about the two caps I described. From the former posts I gathered that the two caps I described are not a corvette application. So I guess that the cap with "AC" in a circle and "15# RC-15" in a circle is a Camaro or other GM application.

[Patrick H.]

Re: AC cap 15#, RC-15

Patrick I hoped you or Tony would chime in about the two caps I described. From the former posts I gathered that the two caps I described are not a corvette application. So I guess that the cap with "AC" in a circle and "15# RC-15" in a circle is a Camaro or other GM application.

Michael,

It doesn't make a difference. The cap could be for either; small variations are not "common" but have definitely been noted. The AC plant didn't care what car it was going on, just that it was an RC-15.

As Pete Lindahl notes, the one cap could be an earlier cap. Post pictures if you can.

Patrick