Radiator Cap Pressure F134

I need a new cap. The existing cap is so flimsy I know it does not create pressure and the rubber is deteriorated. I am not overheating or boiling over.
I looked in the service manual and it says that the F134 used both 7 & 15 PSI caps. My only experience on 7 PSI caps was on my old Falcons and Comets. I remember they had 7 lb caps.

Any thoughts on which one to use? Have any personal experience stories to share?

Thanks.

 

14psi if your system can take the pressure. It will raise the boiling point of the coolant.

 

The boiling point of fresh water is raised approximently 3 °F for each pound of pressure applied to it.
Therefore with the boiling point of fresh water at sea level = 212° F,
A 7 lbs. cap adds 21°F so 212°F + 21°F = 233°F
A 15 lbs. cap adds 45°F so 212°F + 45°F = 257°F
The actual increase in the boiling point of the fluid in the radiator will vary slightly depending on the % addition of antifreeze ( or other additives) to the solution.

 

I run 7 too