[Michael C Henry]

I just saw a Stant radiator pressure tester kit for $68 at Northern Tool plastic case and all. You install the tester on a full coolant system and start the engine . The pressure should climb slowly as fluid heats up if it climbs verry rappidly you have a combustion leak into the coolant.That is not supposed to happen. If you are looking at a radiator that has a accses or filler cap .Fill the system with fluid and leave the cap off,start the engine and watch the fluid. It should be just fluid circulating .It will rise slowly pushing upward in cap area and spilling into the tube that should go to the overflow tank. If you see bubbles ,that is a combustion leak. On a cold engine there will be verry little circulation seen at the radiator untill the thermostat open . It should be a slow expansion. but there should be circulation in the engine. test the thermostat neck as it heats up should be s slow steady increase untill thermostat minimum temp is reached. temps should be almost the same front to back on the heads.