Heater core only stop leak?

[MountaineerTom]

No doubt, if I don't do it, Murphy will come to town.

Here's my plan: I picked up an OEM heater core. I am going to buy one of those AC charge kits that includes dye and the light for checking leaks and charge it up (I bought it with non-working AC). I'll then check all of the system except for the evaporator for leaks.

Then, I'll bring it to a shop to have it leak tested (to see if they find anything I don't) and evacuated and then when I have the HVAC box open, I'll check the evaporator with the light for leaks.

Does that plan make sense?

I know I'll need a set of quick-connect tools to disconnect the evap. Are there o-rings on those lines that I should replace? I would like to get the AC working again some day.

Sound good to me. The shop I got mine evacuated at held pressure on it for quite a while to make sure there were no leaks.

Yes, it would be a good idea to replace the O-rings where the evap core connects to the pipe. I lubed mine with some PAG oil.

 

[PatMc]

The internal passages in the tubes are much smaller than you'd think in a heater core....030" or so. If it's corroded enough to leak, then corrosion has probably built on the inside of the tubes making them considerably smaller than they started out and are mostly clogged anyway. StopLeak will clog them the rest of the way. Just bypass it until you can do it right.

 

[RMETeeJay]

Thanks. I did pick up an OEM core to replace.

 

[Flivver250]

I don't really know. I figured it was the same age as the heater core and I know I would be kicking my own ass if it went out after not replacing it. LOL

My evaporator leaked so I did the heater core at the same time. Replace them both and don't look back. Murphy will bone you if you try to save a dime.

 

[RMETeeJay]

I picked up an AC recharge kit with dye, so I'll be able to tell if the evaporator is leaking or not.

 

[RMETeeJay]

Pictures for science. Thankfully, no leaks on the evaporator.

As you can see, my core failed where the plastic is crimped under the steel. My guess is that the plastic shrinks with age and the crimps lose some strength from the pressure of the cooling system.

There is no way that a leak stop would have helped. Thanks to all who suggested replacement. It wasn’t that bad, just time consuming.