The Stovebolt Site Forums The Shop Area Engine Shop Air Bubbles in my Anti Freeze

I added some antrifreeze to my 235 CI and ran the engine for a while to circulate it through. I had the radiator cap off and noticed a lot of air bubbles in the radiator.
Air must be getting into the system somewhere. Does anyone have advice on how I can pinpoint where the cause of the leak is located?

Is it losing coolant? It can be anything from a head gasket to a cracked head to a water pump sucking air. Do you have a thermostat in it. Running without a thermostat can sometimes churn things up to where it looks like bubbles.

..do you know a friend that can put a vacuum test on it?

If you have the attachment to blow each cylinder up with compressed air it will point towards a head gasket or cracked head issue. It will leak air into the anti freeze and bubble up through the radiator. You will probably hear the bubbling too. I know I did!

air in the cooling system. here is a sure fire test to confirm compression. will work on any pressureized cooling system typical radiator caps anywhere from 7 to 10 to 13 lbs. if the head gasket is leaking compression it will over power the cap and force it to vent. take the over flow tube (may need to put a longer one on for the test)and run it into a bucket of water about 3/4 full now take an empty coke or gatorade bottle and fill it up with water in the bucket and turn it upside down in the bucket and put the over flow tube in the neck in the bottle far enough that it will stayu there. start the engine and let it run. if the heag gasket is leaking, it will force air into the bottle and the water out. with in a few seconds the bottle will float up.