'57 Radiator burping coolant

[Rex P Kelly]

Every time I drive my '57, it burps a little coolant onto the fan shroud. I think it happens when the engine is first shut off. I have a correct 7# cap and was thinking of putting on a higher pound cap for driving purposes only. My question is..Would the higher pressure of say 15# blow off the corbin clamps or cause other problems? ..thanks for your input

[John H.]

Re: '57 Radiator burping coolant

Rex -

Are you topping it off occasionally? I never had the "burp" problem with my '57, but I used to with my '69 Z/28 when I topped it off to the "Full Cold" mark on the side tank after it would dribble about 1/4-oz. on the floor when it heat-soaked after shutdown (I'd find it the next morning). Finally I quit topping it off, and it found its "happy level" about an inch below the "Full Cold" mark - hasn't burped a drop since. It runs at 180 all the time (verified with my I.R. gun), and has never shown any tendency to overheat, in town or on the highway. These old cars without coolant recovery systems need some expansion space to accommodate heat-soak.

[Robert Willis]

Re: '57 Radiator burping coolant

I had the same problem and fixed it by putting a 180 degree thermostat in the engine. I also drilled two 1/8th holes in the outer ring of the thermostat to alow me to bleed the air out before I fired up the engine. Bob

[James F.]