Radiator and A/C repair guys

[Boog]

I'm working on my original heat/ac parts and I want to pressure test the heater core and evaporator before I reinstall them in my truck. I don't want to get the truck all assembled only to have a core failure. I would imagine 30 # pressure on the heater core would be sufficient to test for leaks. Would 100 # be enough to test the evaporator?
How do you guys do it?

[1976gmc20]

All I know is that I had a heater core "repaired" one time and the guy "tested" it with air pressure in a tank of cold water, but when I put it back in the pickup it still leaked

[68C15]

I'd apply and hold 18psi to the heater core and come back and check it every half hour. The evaporator core I'd do the same but use 100psi

1976GMC20, he probably didn't leave it in the water long enough. Air bubbles can stick to the fins and not come to the surface for quite a while unless they are real big. That's why I suggest apply pressure and watch the gauge for pressure drop

[1976gmc20]

Originally Posted by 68C15

I'd apply and hold 18psi to the heater core and come back and check it every half hour. The evaporator core I'd do the same but use 100psi

1976GMC20, he probably didn't leave it in the water long enough. Air bubbles can stick to the fins and not come to the surface for quite a while unless they are real big. That's why I suggest apply pressure and watch the gauge for pressure drop

I think the leak opened up from heat.

Now I can't remember the end result: whether he finally fixed it or I bought a new core, or what? At some point I got stupid, thinking I didn't need a second vehicle while living in town, and sold the pickup

[Ziegelsteinfaust]

Originally Posted by 1976gmc20

I think the leak opened up from heat.

Now I can't remember the end result: whether he finally fixed it or I bought a new core, or what? At some point I got stupid, thinking I didn't need a second vehicle while living in town, and sold the pickup

That is quite possible leaks opening up when hot.

It is quite common in AC coils to find the outdoor one leaking when running. Then indoor coil leaks when the heat is on. Rather heat pump or gas fired.