Surge Tank Cap
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
I think that the change to the 18psi cap was done by a TSB from GM.sometime last year. When I got one and installed it, I didn't see much of an increase of coolant temps; maybe 2-3 degrees. I got mine from Amazon for about $10. Shouldn't hurt anything by upgrading.
Drifting
Joined: May 2008
Posts: 1,693
Likes: 490
From: Denver, NC
The extra 3psi raise the boiling point of water 9 degrees. The new cap is 18 psi. It will not make the engine run hotter or cooler - it just raises the boiling point.
Last edited by Ed Ramberger; Sep 6, 2020 at 08:30 PM.
