My AC doesn't hold a vacuum, so I'm trying to use some UV dye to find the leak. I replaced the orifice tube; it had lots of crud on it. Being stupid, I didn't realize the cheap gauge set I bought at Harbor Freight had a leaky yellow hose out of the box. Even though the compressor wasn't kicking on - the system was bone dry - I thought I was getting refrig into the system because the cans were freezing up and slowly emptying out. Instead, I just contributed several cans of r134 to the atmosphere. Figured it out and bought a separate charge hose; then jumped the low pressure switch to start the compressor. Got about three cans plus the dye injection into it.

That's prolly more refrig than I needed to waste, but I wanted to see the compressor work, and the air get cold, which it did. Hopefully, after running it some today/tonight, I'll be able to see where it leaked out; then, I can replace the drier, flush the system, fix the leak, and confirm a vacuum, and recharge.

The question I have is about the icing up on the lines I saw today as I was adding refrig. First, the line containing the orifice tube iced up all the way from the the evaporator box to exactly where the orifice tube began. On the other side of where the orifice tube was in the line, towards the condensor, the line never iced over. It made me wonder whether I put the orifice tube in backwards.

DISCLAIMER: I'm a screw-up old man with a terrible memory.

Mine has the red style orifice tube, one end seems to be all filter screen and the other is more solid, as if there is a small valve or sensor inside. I put that solid end into the line first, leaving the screen end closest to the line opening. Was that the right way?

A few minutes later, the other, fatter line coming out of the evaporator iced up a little too, then, within another couple of minutes, they were all thawed out, and the AC seems to be basically working - prolly still a little low on 134.

I took my jumper out and plugged the low pressure switch back it and the compressor kicked on by itself. It started cycling, running 30-60 seconds at a time. High pressure was around 190-200 and the air is cold in the cab.
It wouldn't

 

Watch him take his out around time index 2:25 and you can see the direction it is.

 

thank you, sir. I put it in correctly. Not sure why it froze up, maybe blockage in the line or evaporator? Or maybe it's supposed to work like that, or after a long non-use? Like I said, it melted off and was all clear later. Thanks, not sure why I can't find decent YouTubes.