My factory original radiator had an aftermarket radiator cap. I decided to replace it with an original style cap. The one I got from Fusicks doesn't have a seal at the cap base. Only the sea isl at the end of the spring. When I tried to use it coolant would spit out at the cap base and get all over the wheel well. The aftermarket has a gasket at the base and doesn't do this. Shouldn't there be a gasket there so any overflow would go down the tube rather than around the cap?

 

What year & model vehicle? Who is the manufacture &/or part number of the radiator cap? Is the radiator cap rated 16psi?

 

The one in the photo was bought from Fusicks. Supposed to be for a 72 without recovery system. 16# https://www.fusickautomotiveproducts...p?number=RC15R

 

The radiator cap you posted from Fusick is not for a 1972 Oldsmobile. Perhaps you made a mistake in the purchase or in the URL link you provided?

Reproduction Radiator Cap, 1957-69 Buick, Cadillac, Oldsmobile1957-68 Buick all models except 1963 Invicta & Wildcat with A/C

1969 Buick all models except those with coolant recovery

1960 Cadillac all models with A/C

1961-68 Cadillac all models except those with coolant recovery

1957-60 Oldsmobile all models with A/C

1961-67 Oldsmobile all models except those with coolant recovery

 

There are several manufactures of radiator caps which should fit your 1972. I've had good luck w/ Stant, but there are others, Gates, Standard, etc.

This one should fit:

 

I'll note on OPGI that radiator cap RC-15 is listed as fitting a 1972 Oldsmobile. You really have to double and triple check these auto parts stores - they are CLUELESS as to what fits what.

OPGI URL link fitment: $40 for a radiator cap? Go (Run) to an auto parts store and let them get you one...no shipping and many probably have it in stock.

1961–1973 Oldsmobile Cutlass

Rock Auto demonstrates the following:

https://www.rockauto.com/en/catalog/...iator+cap,2068

 

I bought it directly from them at the OCA national meet. The website it is for a 72.

 

I have one that works that isnt an original style. It has the gasket on the cap. It works but isnt the original style so I was trying to get an original style but cant fond one that has the gasket and is correct to what came on it originally. Maybe no one makes one.

 

My mistake, I guess I didn't see the "elevator" on the page allowing me to scroll down further. Trying to help you out, you might need to wait for others to chime in. The image below I took from the 1975 Parts Book; however, in some of my readings elsewhere, I believe they "revised" the RC-15 and I note in some catalogs it's listed as a second RC-15 item - second as in a second type build of RC-15. I'll provide you with the Part Number book numbers. Y72 was the H.D. Coolant System. Good Luck. Sometimes you order Egg Foo Young & you get Chop Suey.

 

Well, to your point, I believe the OEM radiator cap was, in fact, rated @ 15psi. Sorry, I'm not of much more help, it's sometimes a coin toss on part numbers especially if they've been superseded then add to the fact some manufacturers do list stuff that just isn't right at all. To be honest though, this is a great area to walk into NAPA or another parts store and let them get you one that works - let them to the leg work and pay for shipping. I do like Stant radiator caps. Good Luck!

 

So, here's a thread worth a read. I owned a 1967 442 and a 1972 442 back in the day (1969 & 1976). Noteworthy is the one members comment regarding the size of the "ears" on the OEM style radiator caps back in the day. Yes, my radiator caps back in the day had the big "ears".

Correct Radiator Cap

 

Stupid Money >>> https://www.ebay.com/itm/325505714986

 

"Officially" licensed part....>>>>>.....https://www.heartbeatcitycamaro.com/...-GM%23-861050/

 

If you do not get the issue resolved with the Fusick cap, I would look at what Ames Pontiac has to offer.

Don W