A/C leaking.

[Big_John]

The a/c system on my 70 300 was MIA when I bought the car. The only thing left was a broken vacuum switch and an evaporator with twisted off fittings.

So... I bought a knock off Sanden compressor with bracket, condenser, dryer etc. from Bouchion Performance (great guys to deal with). I found a replacement evaporator on Ebay and a new switch at Rock Auto.

Bolted it all together and pumped it down this winter. It was too cold to work on it, so I closed it up and waited for warmer weather. It held vacuum for 2 months, so I figured it was good to go.



Filled it with R134a and got it working.... crap.... It leaked out. Checked all the connections, tightening one at the evaporator and refilled it and included a can of freon with the green dye. Again it leaked out.... Looked with a UV light and can not find the leak! It does maintain some pressure, so it's not dumping everything... but this is getting frustrating.

I don't think it's the evaporator because it held vacuum... That is the only piece I can't really see.

My a/c experience is pretty limited.... But I'm thinking some sort of internal compressor leak.

Any ideas???

 

[barnfind]

REPLACING RUBBER HOSE LINES
is preferred for two keys reasons. First you must remember the "age" of the car. If you have an 1987 or older model year then your rubber AC lines are now over 12 years old! You most likely have replaced a few hot water coolant lines by now if you are prudent, and it does not make sense to have the system charged hoping they won't leak slowly over the season. Second, with the introduction of R134a came "barrier" hose line. Basically a hose within a hose that limits the probability that smaller R134a or even R12 molecules will slowly escape through the hose wall over time (why are you topping off the refrigerant every other year).

 

[Big_John]

New hoses throughout.

 

[barnfind]

R134 rated or R12 rated?

 

[Big_John]

R134 rated or R12 rated?

R134a rated.

 

[barnfind]

Id question the evaporator
Any green on compressor seal?

 

[Big_John]

I think I found it...

I just looked at it again with the UV light and found a drip of green. Looks like I have a pin hole at one of the fittings where it flanges for the hose. Today's drive must have finally pumped it through enough to find.

 

[commando1]

Whew.
If it was Gary's car, it would take 600 postings...

 

[68plymouth383]

:yes_no:

 

[Big_John]

This was really frustrating but now it's found I understand why I couldn't find it.

The leak is in the hose coming from the top connection on the condenser. I put a 90 degree elbow at the point where it goes through the radiator support. The angle of the hose is just right so the dye didn't collect on the hose or fitting... Instead it dripped directly on the ground.

I only found it because it dripped on the headlight wire.

I think it might be a bad crimp and that makes some sense now why it held vacuum so well. New fittings are on their way and I'll just make a new hose.

 

[march]

Ensure that the R134A includes dye, or add it, otherwise you won't see the leak.

 

[70NPORT]

Whew.
If it was Gary's car, it would take 600 postings...

599

 

[The Horvaths]

Glad that you're onto it. Just to point out the obvious: vacuum can "self-seal" a number of types of leaks. The system doesn't operate at vacuum. It operates at pressure. So, pulling vacuum may not indicate a leak when pressure will. Now, finding that dad-gummed leak can be a whole other story!

 

[Big_John]

I made the hose last night and got it installed and charged this morning. So far so good. 38 degree air from the center vent. I'll check it again tomorrow.

Everything in the conversion went real well except for this leak, so I can't complain... but I leaked enough Freon out that I'm expecting a scolding letter from Al Gore any day...