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!


1949 Chevy 3600
1975 W-25 Hurst Olds
1970 GMC 1/2 ton Fleetside
2010 Chevy Silverado