So after a complete restoration on my 72 Cutlass I recharged the ac it cooled very nice. The next day I noticed an oil spot on my shop floor. I put the car on my lift it was leaking out of the condensation drain at the bottom of the evaporator box . After several days of sitting it stopped leaking and now the ac doesn't cool any more. Any thoughts?

 

Sounds like the evaporator core is leaking. Maybe you'll get lucky and a connection was left loose or an O-ring was left out.

 

I would agree with the leaking evaporator core, On my 1970 Rallye it was the core due to the wrong self tapping bolt used for the inner heater/ a/c box and it went into the top of the evap core.

 

That's what I thought sounds like a good winter project. I'll be looking for a good used evaporator coil.

 

With refrigerant lines disconnected the core could be isolated and vacuum tested for leaks in place before removal.

 

My '71 CS was leaking exact same spot. I replaced w/ a new core. New evaporator cores are readily available.

 

Replace evaporator and test with nitrogen the fittings on the new one

if no bubbles pull vaccum and recharge

 

connections are outside of the drain pan

so it wouldn’t be leaking out if the drain pan

 

It's not a connection for sure.
That's a good idea to isolate it and test it. I think I'll do that.

 

you know it’s leaking. Unless you are a really good aluminum welder you ain’t fixing it

just get a new one. They are not that expensive

 

The Parts Place has real GM evap cores for 220 bucks, thats where I got mine.

 

Thanks mister.

 

I've purchased many products from Old Air Products to include the new evaporator core. Extremely satisfied w/ their workmanship, service & support.

https://www.oldairproducts.com/produ...aporator-coil-

 

Make sure you add oil to the system.