A/C leaking Freon when compressor engaged

Picture attached. Can clearly see that this is a valve (brass colored) on the aluminum manifold hose block that is attached to rear of compressor. The compressor engaged as it should when initially charged. But we never ran engine above idle with hood up, so we never saw this "purge" on first day. It's my belief that after a few days of light use, enough Freon has purged out where now the compressor only engages for a couple seconds. A few more cycles and I expect it won't engage at all anymore.

Also attached a short video of it purging. Compressor only engages for a split second every few seconds. When you see the short purge, that is when compressor is engaged. Holding accelerator at about 2,500 RPMs.

My brother has gauges, can look at pressures again this weekend. I can tell you that when we initially filled system everything on the gauges looked within range at the time, and the compressor clutch cycled normally (every 20 seconds or so).

One thing I do remember we thought was odd at the time. Was how quiet the compressor was when clutch was engaged. Maybe just because it was new and was still getting pressurized as we waited for the freon to enter.

Evaporator and condenser were both pressurized and capped from manufacturer so you were assured of no leaks at install, so I can't see where there would be restriction inside either of them. That leaves drier/accumulator, compressor, and orifice tube as possible culprits. Since orifice tube is only $3.00, but plays such a big role in reducing pressures between condenser and evaporator, that is my #1 suspect.

I figured since system virtually empty as it sits now (in theory), that I might as well take $3 gamble and install another orifice tube before recharging. If I just recharge, I'll just get same result and lose more Freon.

Okay, so connected gauges and pressures were all off - high side was only 100, low side was 80 with compressor off, and reduced to 35 as compressor ran. This lead us to think definite restriction somewhere. My guess was orifice tube since I had replaced all parts including hoses and I could not remember the orifice tube that I installed being red, I remembered it being darker. Captured Freon from system and removed orifice instantly saw metal shavings on orifice tube screen and noticed tube was purple not red. Red =.062in. Purple slightly smaller at.0605in. Metal shavings indicates that the brand new compressor wreaked itself on initial run. So will replace compressor again and back flush all other components.

Yes, I did file warranty claim on accumulator and ordered another new one. I think the return process for the compressor automatically requested that a new orifice tube and accumulator had to be ordered to get refund on the compressor. I will update when we try again! Lol

Awaiting new condenser, but received replacement compressor and drier. These compressors have a big sticker that states "contains 7oz of PAG46 oil, more needed if have rear AC" . My 1998 Explorer calls for 7oz of oil in system, so I assumed all was well. I opened new compressor today dumped and measured oil - I got almost 3oz after 20 minutes of draining and rotating unit to pump oil out. No wonder the last one imploded! A mechanic friend suggested that I add some oil to the other components, that the Freon actually kind of "rides" on the oil and it's good to have a bit throughout the system. So this time I will personally add 1oz to condenser, 1oz to evaporator, maybe a tad into the manifold lines, and remainder of 7oz into compressor. Maybe will get to reinstall this coming weekend.

Replacement parts all finally arrived and installed. Backflushed the lines and evaporator with AC solvent flush and air. Filled compressor with most of oil (added some to condenser and evaporator), connected everything, vacuumed, added freon, all was looking good, then. Blow-off valve started up again! High pressure not even up to 200 PSI yet.

So we figured that valve must be bad - it's on the manifold hose block so it wasn't replaced with compressor. Evacuated Freon and dug the original valve out of trash swapped. Repeated everything and looks like we got A/C now!

Turns out that valve was adjustable (could see the tiny allen wrench shape in it after removal) - it was not tightened down as much as should have been. No way for us to know how tight is correct so the original factory valve will have to do. As usual, $100's of trouble over a 20 cent part that has info available on and you can't even buy individually.

Thanks for the help, and I hope someone else finds this story helpful.