[B]

Short answer 14 PSI but see this thread for more details that may apply to your situation.

/threaddetails.asp?Category=Chassis%3E&ThreadID=8114#68247

[Sam]

Hey David can’t find that thread you referring to?

[Sam]

I just tried pasting the string in my reply into browser address line and it goes right to it.

Maybe this will work.

“Radiator” vs overflow tank Cap

Also can get to it by going to main page, putting “radiator cap” in the search box. Pick the one that says Radiator vs overflow cap by Jon

[Archived]

Mine has a new solid cap where you fill it and on top of tank it is a pressure cap I have an Aqua Hot cap on it but it is 13 psi the old cap was in bad shape it was 14 psi so I put on one that I had to get by.

[Norman]

The reason for pressure caps is twofold. First, by keeping the cooling system under pressure it raises the boiling point of the coolant. Theoretically we will not be running at our coaches with coolant temperature at the boiling point. The second purpose is to relieve pressure if it exceeds a value the engineers thought was an excessive pressure. In reality we should never exceed that pressure because when it opens we lose coolant.

[Chad]

my top cap is 7 psi. my fill cap is 14 psi.

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1984 96" with 8V92TA

(remodeled Liberty Coach)

Greenwood, MO

[David]

Mine had a 13 psi cap in bad shape, replaced it with the same thing, a Stant 10329 Lev-R-Vent Radiator Cap, 13 psi. $6.19 on Amazon.

[Roscoeapproved]

14#.

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Jeff and Lindsay

91 Marathon XL

[Mike, 92 Country Coach]

Thank you, I will look for a new 14# cap…

Dave

[DON]

Dec of 2021 I installed 2 new caps for our cooling system surge tank, Prevost# 550606 is the top 14# pressure cap, and Prevost# 530191/052355 the filler cap.

[Dave]

Yes do as Don says,I did the same, the filler cap the rubber is most likely shot

[Dick]

Found a 13lb. cap at NAPA that holds 12.5 lbs. I looks like a quality built cap. That should be OK…..

Thank you

Dave