65 RC-26 Radiator Cap

[Michael M.]

I was looking at a RC-26 radiator cap on E-Bay and noticed that instead of having AC in a circle on one ear has TVS stamped. Is this a reproductioners stamp or did someonne other than AC make caps? Looking around I found a second one with this same marking. Just interested. Thanks, Mike

[Don G.]

Re: 65 RC-26 Radiator Cap

After investigating this question for judging purposes, it appears that known original Corvettes have the AC logo cap into the 1993 model year and the TVS logo appears on known original cars in the 1994 model year. Also, TVS caps appear in AC DELCO boxes as service parts. Because the sample size is small, we need more examples. Hopefully, owners of known original cars will respond with their information including model year and build month/year.

If more data supports the early data, it would appear that the cap production was outsourced and TVS became the OEM part in the 1994 time frame and also became the current GM replacement for 1993 and earlier models.

[Peter L.]

Re: 65 RC-26 Radiator Cap

Mike - From your explanation, I suspect you are looking at one of the RC-26s with the stainless steel covers. So although it will function fine, it's appearance is different from the original RC-26 radiator pressure cap that would have been used on a 65 Corvette. The original RC-26 radiator pressure caps used in the 60s, and early 70s were zinc plated steel.

Since you are looking for a RC-26, I figure you have an air conditioned car, so please note that the configuration of the stamping on the top of the cover on the 65 and earlier RC-26s is different from the RC-26s used starting in 1966 and used thru 1972 or so. Non-air conditioned 65s used the 307 radiator pressure cap.

Pete

[Michael M.]

Re: 65 RC-26 Radiator Cap

Thanks Everyone, Yes I was looking for an original RC-26 and had read Joes article in the driveline or restorer which was a great help but saw that SS TVS and wondered where that came from. I searched TVS but found nothing in the archives. Mine is a 65 with air and I will continue the hunt for an original cap or something a lot closer than I have now. Thanks, Mike

[Wayne M.]

Re: 65 RC-26 Radiator Cap

.....Since you are looking for a RC-26, I figure you have an air conditioned car, so please note that the configuration of the stamping on the top of the cover on the 65 and earlier RC-26s is different from the RC-26s used starting in 1966 and used thru 1972 or so. Non-air conditioned 65s used the 307 radiator pressure cap. ....

I just knew that Pete would join in . Here's a variation (probably original cap -- was on my car in 1980) off my early '65 014xx C60 [Pete has seen this pic before]. One of these days I'll have to clean it up, at the risk of destroying the "patina" .

[Don G.]

Re: 65 RC-26 Radiator Cap

Pete/ Mike

There are many radiator caps out there that the only difference between the caps is the TVS designation versus the AC designation. As I said in my earlier post, the AC designation seems to have been replaced by TVS in the '94 model year. The AC Spark Plug Division went through name changes with the spin-off of the components divisions and became part of Delphi. They continued to use the AC trademark until Delphi ceased cap manufacturing operations. The original AC facilities have been torn down and GM oem and AC-Delco sourcing has placed the business with TVS and they appear in the replacement market as AC-Delco parts as GM approved replacement parts. They may also appear in GM service part boxes through GM dealerships supplied by AC-Delco. AC-Delco continues to operate as part of GM because GM did not find a buyer that would meet their price for the AC-Delco business in the past year.

The line has blurred between GM and non GM parts. The only distinction is that if it comes in a GM service part box or an AC-Delco box it is a GM approved replacement part. However, once it is out of the box and on the car, it loses it's identity as a GM part. I suppose for judging purposes an owner could retain the box as some indication of it's origin.

[Michael M.]

Re: 65 RC-26 Radiator Cap

Thanks Wayne, I copied this off and the next trip to thesalvage yard that has old cars I will look around. Mike

[Michael M.]

Re: 65 RC-26 Radiator Cap

I could take a picture of the car it came off of! Just Kidding Does anyone know what the TVS stands for?

[Don G.]

Re: 65 RC-26 Radiator Cap

Wayne

If the third edition 1980-82 Judging manual is correct, it would appear that the cap in your picture was not original to your '80.

The manual says it should be an RC-33 stainless steel cap without ears. Further, it has bold raised letters NEVER OPEN HOT. It also describes the cap as follows: Outline arrows pointing in opposite directions and the words CHECK LEVEL IN BOTTLE. 15 lb. CLOSED SYSTEM and ALIGN ARROW & VENT TUBE are placed around the top of the cap. The same description appears in the 75-77 Judging Manual and agrees with the cap on my wife's 8000 mile '75 bowtie car. If all this is true, it would appear your cap is an earlier design used before overflow bottles were used. Since it is also a 15 lb cap it probably is an equivalent cap from a function standpoint.

[Don G.]

Re: 65 RC-26 Radiator Cap

CORRECTION

I misread Wayne's post. He referred to the cap on his car in '80 and I misread it to mean an '80 model. It probably was original to his car.

My error.

[Sal C.]

Re: 65 RC-26 Radiator Cap

Am I missing something here? How did it get from an RC26 to the 1980-82 Judging Guide to RC33s?

[Michael M.]

Re: 65 RC-26 Radiator Cap

Sal if you look at the 8th post they had got confused with the 1980 picture Wayne had posted of his 1965 Cap. I had asked about the TVS designation which they knew a lot about in the newer models but really doesn`t pertain to the 1965 model other than fit possibly. I kept seeing caps with TVS on E-Bay advertised as original 65 and 66 caps which they aren`t. I wanted to know what the TVS stood for. Now thats just as clear as a bell Right? Thanks, Mike