1954 radiator cap

[Guy M.]

My 4# cap just isn't cutting it, coolant leaks by it. The car runs fine and doesn't overheat. Has anyone run a 7# cap? See any issues doing it? Even NAPA shows a 7# cap for any 54 chevy with a 6 cyl.

[Brad H.]

Re: 1954 radiator cap

Hi Guy... correct Rad. Cap. AC. 778 #4 restored to new by Joe Perri worked perfect on my 54. hake1@comcast.net

[Bob W.]

Re: 1954 radiator cap

Guy, Joe perri past away a few months ago Tim a ncrs member purchased his business. Check out the post Radiator and gas caps for his phone number.

[Guy M.]

Re: 1954 radiator cap

Thanks guys I appreciate the help. Has anyone run a 7# cap? What might the ramifications might be? I have a high performance core in my radiator. Should be able to handle 7# you would think.

[Guy M.]

Re: 1954 radiator cap

I still have this issue, will a 7# work just for driving around a bit without ramifications? Thanks!

[Jim L.]

Re: 1954 radiator cap

I still have this issue, will a 7# work just for driving around a bit without ramifications? Thanks!

I would use it without hesitation, Guy. In fact, I believe that's what is on my own '54.

[Guy M.]

Re: 1954 radiator cap

Thanks Jim, I sure appreciate that confidence boost. I can always put the 4# if judging.

[Tim B.]

Re: 1954 radiator cap

Guy,
There are 2 gaskets in your Radiator Cap. It could be the internal one leaking. I can check out your Cap and see if it just needs a rebuild. Also I can replace the 4# spring with a 7# spring if needed or desired .
Tim Bartsch
GEN2 Restorations

[Brad H.]

Re: 1954 radiator cap

I have a perfect AC 778 #4 Joe Perri cap. Brad.

[David L.]

Re: 1954 radiator cap

Is the 53-55 Corvette chrome 4# radiator cap, GM # 850778, the same as the 48-53 Chevrolet passenger car cap, GM 850796, except for the chrome plating? I have a used 850796 cap stamped "AC", "501", and "4#". My 1957 Chevrolet Parts Catalog describes the 850796 cap as "pressure type (dbl. ear-marked 501)".
Dave

[Tim B.]

Re: 1954 radiator cap

The "501" is a service, over the counter replacement for the 850778 Radiator Cap. It will function the same as the "778" Cap.

[David L.]

Re: 1954 radiator cap

The "501" is a service, over the counter replacement for the 850778 Radiator Cap. It will function the same as the "778" Cap.

Tim,
Is the chrome 53-55 Corvette cap stamped "778" and the 53 Chevrolet cap stamped "796"?

I have a NOS AC cap in the blue AC box labeled RC-3 7# 850797 with the cap stamped "AC", "MADE IN USA", "PAT'D", "13" AND "7#". The specification chart and instruction sheet inside the box is dated July 1954.

I also have a NOS AC cap in the blue AC box labeled RC-12 9# 850994 with the cap stamped "AC", "940 - 9#", "RC-12", "MADE IN USA", and "PAT'D".
Dave

[Guy M.]

Re: 1954 radiator cap

Thanks for all this info, I would love to get the correct cap, anyone have one and willing to part with it? Then ill send it to Jim to put a 7# spring in it if he's willing to do it. Thanks again Jim and all!!

[Brad H.]

Re: 1954 radiator cap

Guy, I have a correct 53-54 restored cap. A.C. 778 #4 by Joe Perry. ncrs Classifieds car parts C1, craigs list 7153380400. 360-580-3426 Brad.