Anybody got a good test idea for testing a heater core? When we bought the car (75 L-48 convertable)The heater core was unhooked but the hoses ran all the way to the core and the core it's self had caps over the inlets and when I took the caps off there was a small amount of anti-freeze inside. Since the car came from Arizona I am hoping that it was unhooked for heat reasons (not leak reasons). I was thinking of testing it with 15-20lbs of air to see if it holds. Any tid bits of wisdom out there?

Giving it an air pressure test is how a radiator shop would do it...it makes less of a mess if it leaks air than coolant! Pump it up to 15 or more pounds of pressure and see if it holds it or not.

Hi HogWild, Gunslinger is spot on I work in a radiator shop here in Aust thats how we test them!! The general rule is what cap pressure is what you test them too!eg 13lbs cap thats what the whole system runs .We stick em under water with presure in them if it's gunna leak you'll find it !!!you can go a bit higher few lbs to be on the safe side ,hope this has helped Cheers Mick