Radiator Cap Identification

[Timothy B.]

Can anyone tell the application of this cap.

Thanks in advance for your help, Tim

[Edward J.]

Re: Radiator Cap Identification

Tim, my 72 coupe w/c60 has that cap with those markings, and believe it fits cars with the copper/brass radiators 70-72 maybe some mid years also.It also has the brass rivit which the cap fits onto the radiator directly, not a remote tank style.( that cap has a alum. rivit in the middle of cap)

[Joe L.]

Re: Radiator Cap Identification

Can anyone tell the application of this cap.

Thanks in advance for your help, Tim

Tim------


Th RC-15 was a quite common cap. As far as Corvette goes, it was used for 68-68 with big block (except L-88), and 68-72 small blocks with copper brass radiators. However, it was also used for many other 66-72 GM applications.

It was discontinued several years ago. However, the style RC-15 you have pictured was replaced by a stainless steel shell RC-15 about 30 years ago.

[Patrick H.]

Re: Radiator Cap Identification

Yours with the "depressed rivet" tends to show up from 66 to 69 (?).
70-72 tends to have a "flat" rivet.

[Edward J.]

Re: Radiator Cap Identification

Patrick, mine does have a brass rivit, flat rivit ? hmmm. Ill look at it alittle closer.

[Timothy B.]

Re: Radiator Cap Identification

Thanks everyone for the information on the radiator cap.

I want to buy a cheap radiator cap from GM to use the vacuum vent and gasket to restore the seal on this cap. Is there supposed to be a gasket just under the cap?

Joe, do you know off hand what part # GM cap is good to get for the parts I am seeking.

[Paul O.]

Re: Radiator Cap Identification

Timothy for 63-64 cap you should have a RC-307. This cap had a hard material type gasket between the radiators opening and the bottom of the cap.
The gasket looked black to dark gray with what looked like fiber strands in it. The 307 cap has a different configuration and wording then a RC-15 and I think it was rated at 13# not 15# like the RC-15. Plus the center rivet was aluminum not brass. Paul 18046

[Peter L.]

Re: Radiator Cap Identification

Tim - Most of the AC 1966 and newer radiator pressure caps have the same lower valve components. The exception is the 1966-1972 RC-26 radiator pressure caps that had aluminum components. Check them out. Use a cap that has AC stamped on it and brass or stainless steel components and is made in the USA, NOT one that is stamped TMS or whatever is made in India or elsewhere.

The original RC-15s did not have the large fiber gasket.

Pete

[Joe L.]

Re: Radiator Cap Identification

Thanks everyone for the information on the radiator cap.

I want to buy a cheap radiator cap from GM to use the vacuum vent and gasket to restore the seal on this cap. Is there supposed to be a gasket just under the cap?

Joe, do you know off hand what part # GM cap is good to get for the parts I am seeking.

Tim------


Unfortunately, most, if not all, of the radiator caps available today from GM/Delco are foreign-manufactured pieces of a different design than the originals. I really doubt that any of these would provide suitable donor parts for replacements for an old-style cap. It's possible that they will, but I doubt it.

I believe that cap restoration kits are available, though, from the major Corvette parts suppliers. I think these will include the parts you are likely to need.

[Timothy B.]

Re: Radiator Cap Identification

Thanks again Joe,

Here is a pic of a RC29 cap I bought at Carlisle a few years ago for a buck. This fellow had about ten and I should have bought all ten. The cap had the top gasket and also the rubber and vent valve.

The pic makes the 307 look like the rubber is coming out but it's not.

[Joe L.]

Re: Radiator Cap Identification

Thanks again Joe,

Here is a pic of a RC29 cap I bought at Carlisle a few years ago for a buck. This fellow had about ten and I should have bought all ten. The cap had the top gasket and also the rubber and vent valve.

The pic makes the 307 look like the rubber is coming out but it's not.

Tim-----


I don't know if these parts would be interchangeable, or not. For one thing, the RC-29 was used for systems with coolant recovery tank. The RC-15 was not.

You would still need the center rivet as you won't be able to save that.