Radiator cap and vent pressure

[Touring5]

In preparation for doing a coolant change on my '87 Buick, another question/concern has come to mind.

Several years ago the stock radiator cap developed a tear in the gasket. The original cap was a AC #RC27 and had "15 psi" on it. When I went to a local parts place (I don't remember where) they only had Stant replacements. I bought the one they said was the correct replacement and it fit properly. The only difference was that the Stant was marked "16 psi". I was told at the time that it wouldn't make any difference, but now I'm wondering if that 1 pound would make any real difference? Since the car is nearing 25 years, is there any concern that the slightly higher pressure could cause any issues?

I see that the RC27 is available for about $13 on Amazon, but would it be wasted money?

 

[JHZR2]

Lower pressure, if achievable without release, is always better wrt stress on components.

I have original cooling equipment on cars that are 30 years old and over 200k working fine.

 

[Quest]

IMHO that 1 pound difference shouldn't be an issue, afterall.

Q.

 

[Chris142]

Gm likes the 15lb caps but the aftermarket doesn't normally have a 15 so they use a 16. 16 is fine as 1 psi won't make enough difference to matter.

Plus a 15lb cap may not open exactly @ 15psi. Might be 14 or 16.

I agree with JHRZ2. The less pressure you can run w/o boiling over the better.

 

[Stu_Rock]

I probably wouldn't sweat the 1 psi difference. There is also a 13 psi version if you would be more comfortable going that direction.

The ACD RC27 is probably made by TVS in India. Stant (Mexico) is a higher quality part. Motorad/CST (Israel) from AZO or ORLY are also good.

 

[Al]

Originally Posted By: Chris142
Gm likes the 15lb caps but the aftermarket doesn't normally have a 15 so they use a 16. 16 is fine as 1 psi won't make enough difference to matter.

Plus a 15lb cap may not open exactly @ 15psi. Might be 14 or 16.

I agree with JHRZ2. The less pressure you can run w/o boiling over the better.

This

 

[Warstud]

The worst thing that could happen is....it could raise your boiling point about 3 degrees.

Oh wait...that's a good thing.