I've been on here for a while and know about the dreaded rear AC pipes near the driver rear suspension but the visible areas seem fine (and for the life of me, I don't see how ANYONE ever gets contact out of that location!)

Long story short, I let the disco sit WAY too long (about 5-6 months) 2 winters ago in a barn and while it worked okay mechanically (never good to have them sit that long) I think the damage was done to the AC system, as it seems an o-ring had dried up, cracked, and let freon out.

Since then I've been chasing an issue... I replaced or rebuilt all my tensioner pullies with only the AC comp. pulley remaining (squeaky) so I threw a used compressor from an indy LR guy on there since it might help diag the leak anyways.

No pressure in system anyways so he did an evac / vac test etc w/ snap on auto unit, no leaks detected under vac but while it worked okay for a week or so.. it soon started to fade intermittently (although the compressor always turned on, so not a huge lack of pressure for the safety switch I guesss). Then towards end of summer, it really started staying warm, especially on passenger side (I read this in another A/C diag thread on the brit forums, I know you'd THINK it was the blend flap stepper motor failure, but that's a strange coincidence that he was in the process of a recharge / leak diag as well! He also described the exact same AC "gurgling noise" when the vehicle was shut off, which got worse / more alarming as the system stopped functioning as well!)

Now after it's been sitting on and off for a few weeks at a time, I tried the AC again and the compressor won't turn on, so now I know there's insufficient pressure to trigger the press switch and enable compressor operation.. definitely was a leak.

[So after it sat for those 5-6mo it was totaled and I rebuilt it w/ facelift core support / front end etc. It has a solid condensor / drier can and those o-rings are good including the pipe that corrodes on some UK vehicles up front through the core support area. After this I did the compressor and leads me to the rest of story above.]



That kinda narrows it to under dash or something in the rear evaporator? I floor manage a shop and can get a vac pump / gauges but not sure about the dye / UV light.. guess I can buy some of the stuff. Not sure how much stuff I should tear apart to access the system first though.

 

The only problem with the dye is you have to fill the system freon and and run it until it leaks out again. You can also use nitrogen to test with with out have to run the system.

 

You could use nitrogen and use an N2 sniffer to find the leaks. Alternatively helium and appropriate sniffer. Don't FFS use argon or hydrogen cos you'll blow yourself into orbit.