Pressure cap

[Buttanic]

I am putting together a closed cooling system on a Chevy 350. The heat exchanger didn't have a cap when I bought it. What pressure pressure cap is normaly used.

 

[FreeBeeTony]

Re: Pressure cap

I'm using ~7lb cap. I originally tried a 14lb and I had a leak between the riser and manifold. I think 7lbs is fine.

 

[Don S]

Re: Pressure cap

I'm using ~7lb cap. I originally tried a 14lb and I had a leak between the riser and manifold. I think 7lbs is fine.

The heat exchanger cap has nothing what-so-ever to do with the riser/manifold gasket leak. <br />Even if it did, using a lower pressure cap means you didn't fix the leak, you just fixed it so it wouldn't show up at the higher pressure. <br /><br />What year and model (Volvo, Merc) engine do you have?

 

[Buttanic]

Re: Pressure cap

It's a mixed breed. It's in a 1977 Chris Craft Cutlass I bought to restore and the engine seems to be Volvo but I am not sure what is original and what is not. Manufactuer is irevelant any way I just need an idea where to start. Most cars use a 14 or 16 pound cap.

 

[Don S]

Re: Pressure cap

12 to 14 psi. Merc uses 14, and I think Volvo uses 12. Some of the after market closed systems are also either 12 or 14 psi. So either should work.

 

[Buttanic]

Re: Pressure cap

Thanks,Don S