entire cooling system is brand new..
radiator
waterpump
thermo
all hoses
heater core

installed new carb and been adjusting it and the timing and noticed the radiator cap is leaking. bought new cap from autozone and its doing the same thing.

1970 cutlass s

is there more than one size cap? this one is supposedly rated at 16psi

and specific cap recomended?

thanks in advance

steven

 

Go back to Autozone and get a safety radiator cap (looks like a regular radiator cap but has a red lever across the top that helps hold the cap in place), also make sure you have bled the cooling system of any air bubbles and that the thermostat is not sticking.

 

Don't fill all the way to the top of the opening, either.

 

Check the cap sealing areas (both inner and outer) inside the radiator neck for nicks, scrapes, or solder globs from the mfg process. I had the later once and I used a broken razor blade to slice it right off.

 

alright may spring the big bucks at get the safety one, in the past they always seemed to wear out faster on me but at this point willing to give it a try. bled the system well when i had it open last. Any way to verify if thermostat is sticking externally?

 

Took your advice, left coolant level below overflow nipple on radiator and it has stayed there. I am thinking maybe the pressure needed to push coolant through small overflow hose is greater than escaping the cap when filled to top. give it a couple more drives to be certain but it seems this may be the trick.

 

checked it out everything looks good probably going to spring for the safety cap and keep the level below nipple and hopefully all is well from here on out. Just hate to see her leaking.