iHateVolvoPeople
Active member
- Joined
- Feb 1, 2014
- Location
- Midwest
You can vent r134a to atmosphere, just don’t post on TB about it. The most important step is going to be a deep, long, strong vacuum to remove moisture. I recommend 1 hour, then close gauges and turn off pump, let sit and boil for 1 hour, then vacuum for an additional hour. That’s a 3 hour process, 2 of which will be spent vacuuming. But replace your receiver drier BEFORE vacuuming, obviously.Don't vent refrigerant to the atmoshpere. I use a machine to recover it. It actually goes back into other cars!
Honestly, if I were in your situation, I would just first inspect the system for leaks (oily residue), buy a can with a guage and see if there is ANY PRESSURE. if it's at 0 psi there was a leak. If it's up to 60-80 psi static, there is SOME refrigerant in there.
If it's at 0psi you lost all the refrigerant. I would then just charge thru the Low side on the back of the compressor (via adapter) and put 80 percent of the R12 spec in there.
I bought a 1990 740 that was sitting for years and all I did was vac and charge, and it's been working for almost a year so far.
Unless you see a big oily leak somewhere, I wouldn't even worry about adding oil right now.
Also, those cans with the gauges built in are utterly useless. Massive waste of money. Walmart sells r134a cans for $4.88 in my area, then you just need a can tap ($10) and you can RENT manifold gauges and vacuum pump for free. That’s it.
All in all you could have functional AC for:
Receiver drier: $15
Refrigerant: $10-$15
R134a can tap: $10
For a total of $35-$40. Well, don’t forget the r12>r134a low side adapter, but it looks like you already have that.
OP I’m not a pro but I’ve been running a very small automotive AC side business in my area since last year. Many happy customers and no returns yet lol. I would be happy to walk you through step by step if you need help.