Warning: Radiator Caps...

[ACME RACING]

I replaced my Radiator cap last week since the rubber in the cap was becoming ragged and torn with a cheap cap from AutoZone. It fit ok , but it wouldn't hold pressure. It would bleed over in the overflow tank and the hoses were soft when hot,(180-190°)....I went to NAPA , but theirs were the same as AutoZone's.... Finally got a AC Delco and no more overflow and hoses were hard (holding pressure).......The cheaper versions release pressure too soon even though they have "16LBs" labeled on the cap.....AC is 15LBs and holds the pressure .....AC cost more but works Part # for AC 10409635 ...................... alan

 

[arista5]

where did ya find the delco?

 

[ACME RACING]

AC

One of our club members works in a Automotive Shop and he ordered it through his GM parts guy at a dealer......Delco cost about $8.00, Cheaper (Stant) cost $3.95..........................alan

 

[Crazi]

Had the same thing happen to me a while back and it wasn't the pressure rating of the cap, it was the "jiggle" valve( the little thing that stops coolant from going to the overflow but opens to let coolant be sucked in to the radiator).

On the correct cap for our cars, there is a spring that holds it closed so the cap can build presure. If you get the wrong one (mine was off by one number) it doesn't have the spring in the "jiggle" valve and it will allow all the pressure to bleed into the overflow. You should check your caps to make sure the "jiggle" valve snaps back into place versus dangling when you pull on it.

Hope I described this well enough...