Bad compressor clutch...need help finding a leak

[robertmk74]

Hello, I am a new member to the forum.
About 3 months ago, the air conditioner in my 2008 Ford Escape started to be no so cold anymore, so as far as I know,there has not been any freon ever added or any AC work done on it.
So I had the remaining refrigerant reclaimed, replaced the high and low side schraeder service valves,(one was leaking) vacuumed out the lines, for 30 minutes, and it held a vacuum. Charged it up with 134a and it became nice and cold again, blowing good.
In about 6 weeks, it seemed it was not quite as cold as it was, but I just figured it was because it was so hot outside.
Then on a 3 hour trip it became noticeable worse, and on the return trip home, there was just warm
air.
When I put the manifold gauges on, there was no pressure period. So I vacuumed it, and surprisingly it did hold a vacuum. I added
a little UV dye, along with a can of refrigerant. It took in a little refrigerant, but the compressor clutch did not engage even for a little. I tried to bypass the low pressure switch, nothing.
Tried the paper clip jump on the relay socket thinking that the relay may be bad...
and I could hear the "click" of the clutch, but no engagement. The low pressure gauge just stayed
at 100 psi, and the high side gauge at 0. No movement of the gauges whatsoever, apparently no clutch engagement at all. Maybe a blockage, or just the fact the clutch is not engaging?
So maybe the freon is leaking from the compressor or even somewhere else, problem is how can I find out where the leak is...without charging it and letting the dye go through the system? I haven't ever used nitrogen to pressure the system to find a leak, or air, (which I don't want to try because of the moisture) I think the clutch is likely bad, so I could just start with a new compressor. And I could have other leaks. Has anyone used air to pressure the system, or is that a bad idea?
Any thoughts on how to proceed will be appreciated. Thanks.

[event3horizon]

I've used shop air. I don't think it's a big deal to try to use shop air but some purists say only nitrogen must be used. You just change out your receiver/drier and put it in a nice deep vacuum once you sort your leak issues and whatever is happening with your compressor/clutch.

I've 'heard' that the system may hold a vacuum fine but a leak won't manifest until system is pressurized. Make sure you check if your Schrader valves are leaking as well.

[Tim]

I've used shop air. I don't think it's a big deal to try to use shop air but some purists say only nitrogen must be used. You just change out your receiver/drier and put it in a nice deep vacuum once you sort your leak issues and whatever is happening with your compressor/clutch.

We used shop air to blow our line and stuff during a repair. The main thing is to have a painter's air/moisture filter on the tank or somewhere in the compressed air output.

[JohnHere]

It's very unusual to have 100 PSI on the low side and 0 PSI on the high side. Are you sure your Manifold Gauge Set is actually connecting to the high side?

[robertmk74]

Yes, the high side was hooked up... The only thing I can figure is that maybe the quick couple valve on the high side schraeder wasn't open, but I do remember checking it.I am going to hook everything up again to verify the readings again.

[JohnHere]

Yes, the high side was hooked up... The only thing I can figure is that maybe the quick couple valve on the high side schraeder wasn't open, but I do remember checking it.I am going to hook everything up again to verify the readings again.

Double-check to make sure that you turn the thumbwheel fully clockwise to depress the Schrader and open the service-port adapter to the system pressure.

[robertmk74]

Will do, thanks

[robertmk74]

UPDATE:
So I purchased a filter/dryer and the fillings to adapt to my air compressor, set the pressure at 50 lbs. Hooked up manifold set to the high and low side
and I could hear a faint hiss, so I was able to confirm that I have a leak somewhere. It was windy, so I couldn't tell exaxtly where it was coming from.
I will hook it up again when I can hear it better. I saw a video online where a guy had a listening wand of some sort.....anyone have an idea where I could
purchase one? Has headphones and a wand, so you can stick it down around the AC components to listen for leaks....

[robertmk74]

Never mind on the wand....just found them online......

[tbirdtbird]

In our shop we will “puff up” the system with refrigerant to about 20 psi with both the hi and lo sides open. Then use a sniffer to find leaks. Very simple to do. And this is allowed per regulations.