radiator cap

[Rick M]

I have a 1976 vette the radiator cap is 15-18 pounds is it wise to use a lower pressure cap being the car and radiator are so old?
Thankyou

[Joe L.]

Re: radiator cap

Rick-----

Absolutely NOT. The purpose of the higher pressure radiator caps used in C3s is to increase the boiling temperature of the coolant. Coolant under, say, 15 PSI boils at a higher temperature than coolant at, say, 7 PSI. If you reduce the pressure relief provided by the cap, you increase the tendency of the system to boil over. You don't want to do that. If your system cannot take the pressure as-designed, then you need to service the system including, possibly, replacing "tired" components.