Question about diagnosing AC system

[thepuzzlemaster]

I've got a '92 4wd front+rear AC van. The AC has never worked since I bought it about a year ago. I had a tech come out and remove any R-12 left in the system, and my plan was to refill with enviro-safe R-12a.

The tech hooked up his machine and it turns out there was no R-12 left in the system.

Knowing the system was empty I filled it with the proper amount of R-12a, one can at a time. At no point during this did the vents blow cold air.

I didn't have a full manifold gauge, but the r-12a did come with an inline gauge. While filling and after the cans emptied, it displayed the correct pressure.

The R-12a did have dye in it, but I wasn't able to spot any apparent leaks.
When the AC was running I could see some bubbles in the sight glass. The liquid in there looked amber colored, for the most part.

The compressor engages when I turn the AC on.

So my question is what's the best way to diagnose this further?
Is the liquid seen in the sight glass just refrigerant? A mixture of oil and refrigerant?
Should I get a manifold gauge and test the pressures, based on the diagnosis steps outlined in the FSM?
Although the compressor engages at the pulley, I didn't verify anything beyond that.

I'm mostly curious about the best options for trying to figure out what's wrong here.

Thanks for any thoughts.

[JDM VANMAN]

Here's a thread that may be of interest, its a 10 page adVanture!!!:yes:

https://www.toyotavantech.com/forum/showthread.php?3483-Charging-Air-Conditioning-System&highlight=air+conditioner

If this is what your looking for let us know and we'll get this thread merged with the other one to keep the established thread resurrected.

JDM

[thepuzzlemaster]

Thanks for that link. I had read through the entirety of that thread quite a few times at this point, haha. It has helped a lot for sure. Although I think my situation is a little bit different than the ones outlined in there.

I was hoping to understand if the inline gauge was useful in telling me anything about the system, but it seems at this point, I should probably get a full manifold gauge and see what kinds of readings I get.

Still open to suggestions if anyone has ideas. But otherwise, I'll report back with my findings.

[JDM VANMAN]

thanks for following up, good luck:thmbup:

JDM