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rad cap pressure rating

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twas_brillig

Jedi Knight
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We just did a camping trip in our BJ7 and I was losing up to 3 litres of rad fluid a day with no obvious leak; went over the Going to the Sun highway in Montana and left enough water tracks there to find that it was coming out of the rad overflow tube; went into NAPA in Kalispell and for about five bucks got the problem fixed. Question: Haynes refers to a 10 psi cap; I think the old cap was a 10; the NAPA is a 7 psi; our car is a BJ7. Any suggestions as to what the pressure rating should be (and there's a bunch of good threads here on original appearance caps, but I didn't find a pressure discussion).
Thanks
Doug
 
I'm thinking the 7 Lb cap is the right one; it is the one on my car.

I remember sometime in the 80s, I was experimenting with raising the boiling point of the water (I was living in southern Louisiana at the time). I might've tried a 10 psi, but I know the next jump to 12 psi was causing the uper tank to bulge! Fortunately, it didn't cause a permanent distortion, but it was enough to convince to drop the pressure back down.

In retrospect, I should've fit the coolant recovery tank then, instead of waiting until a couple of years ago (see the other thread where I just replied).
 
I'm thinking the 7 Lb cap is the right one.

Yep that is what the originals take.----Keoke
 
Thanks guys! 7 psi it is!
Also stopped in at a rad shop and chatted with the chap there, and 7 psi was his gut suggestion as well.
Doug
 
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