I bought a new Motorcraft AC compressor from Rock Auto 2 yrs ago and I was going to install it myself...but then I got busy with a move to Hawaii. I shipped the AC compressor to Hawaii in a big box with other items with USPS.
Then 1.5 yrs ago I had a reputable garage here install it. They also replaced orifice tube, and a couple other things your supposed to replace when you replace the compressor. They pulled a vacuum and were diligent and everything went fine. However they told me that because they were installing a compressor that I had bought independently and brought to them, they couldn't offer a guarantee of any kind, which makes sense...

It's blown cold for 1.5 yrs now.

Then today when I turned AC on, it didn't blow cold, it only blew barely cool. Uh-oh. When I got home I popped the hood, and the compressor was short cycling about every 5 seconds, and no condensation whatsoever on the drier lines. I did not see any visible sign of leaking on the compressor, but it's obviously lost nearly all its refrigerant.

So my question is...What might have happened to make the compressor fail so soon? I don't use the AC all the time or anything. Do you think it just got jostled in the mail during transit when I sent it? Is there any way for all the refrigerant to escape from some other part that might have failed?

Thank you. This is so disappointing...

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You seem to be jumping to the conclusion the compressor has failed. I suggest you get some soapy water in a spray(windex style) bottle, and spray onto the hoses, tubes, fittings, etc of the A/C system. You may have to add some refrigerant to get the pressure to increase, but you may find a bubbling spot readily. If you do, there's your problem.
All of the fittings that connect the tubing to the evaporator, condenser, accumulator or receiver dryer can leak, and the bolt-on fitting connecting the suction and pressure lines to the compressor can leak. The condenser in front of the radiator could have been punctured by road debris, causing a pinhole, or salt spray and corrosion... etc. Get the picture?
Take it to an A/C repair shop, and ask them to check for leaks, or buy a 'halogen? detector' from dariver or dabay to check for outgassing of the refrigerant. Poke the probe into the interior plenum to check for evaporator leaks inside the cab.
The compressor just runs when the pressure is above the low limit, and below the high limit. A leak will cause pressure to drop too low quickly, and will force the LPCO to cut power to the A/C compressor clutch, and no pumpy...
tom

Things do go wrong. I had a replacement compressor go bad after 6 months. The clutch fell off...

Thank you both for the replies.

Tomw0....Okay, I'm going to buy a R134A recharge at the auto-parts store and charge the system, and I'll also bring a spray bottle w/ soapy water with me to spray around and see if I can see any bubbling.

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So I recharged my AC system today. It only took 1 small can of R134-A.
I brought a small spray bottle with soapy water and sprayed all around but didn't see any bubbling.

Then the employee from the auto parts store came out and took the cap off my high pressure port, and she immediately said she saw a little liquid bubbling at the bottom of the schrader valve, but from where I was standing I wasn't able to see anything. I sprayed some soapy water into the schrader valve. There may have been a bubble or two but nothing major, and it was hard to tell if the bubbles were just from the soapy water or if there really was a tiny leak coming from there. So I just don't know if she was correct about the the high port or not.

I guess I'll keep checking inside the high pressure port every time I head out.

I hope it's an easy fix that I can do myself if that's indeed where the leak is coming from.

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If it is cooling with the addition of refrigerant, the compressor MUST be functioning. The actual schrader valve gizzards can be replaced without evacuating and recharge being necessary. There is a tool that will do the job, if you find your gizzards are leaky.
You should keep the blue & red(?) caps on the low and high access ports to keep dirt out and potentially slow down leakage. Sometimes 'popping' a schrader valve, i.e., opening for a short burst of refrigerant, will push out any thing that is keeping the valve from seating properly and alllowing leakage.
When engaged, the center of the compressor clutch should engage, and be turning when the A/C is selected. If it short cycles, mostly that is due to low charte, BUT an overcharge will cut the compressor if the HPCO switch opens due to overpressure.
tom

Thanks for your input.
I always knew the compressor still functioned. I just was worried it had a leak like my last compressor did(and it still functioned too, just had to keep recharging it all the time).

I looked in my high side port with AC on full blast again today. I saw no liquid in there, but I did see some green staining (did it come from the green dye in the R134-A I used on Tuesday? It DID have dye added to it).

A guy told me that if the high side port is leaking, then if I put my fingertip on it with AC on, I should feel a build-up of blowing air under my fingertip. lol. I did that, and I did not feel any buildup of air.

So I'm just not sure at this point what's going on. I did not see any bubbling when I sprayed the components with soapy water on Tuesday, but maybe that's just because it's a very small, slow leak...

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Hi everyone,

So took my truck to my trusted mechanic today to figure out where refrigerant leak was coming from:

The CONDENSER
It's original to the vehicle, so makes sense that it's failing. I'm going back on Friday so they can replace it.

He also recommended replacing the receiver dryer because he said it might have moisture in it which would cause it to not blow as cold. But they just replaced the receiver dryer 1.5 yrs ago when they replaced the compressor, so I don't think I want them to do that. My AC only started blowing warm 3 weeks ago, so I doubt the leak has had enough time to enable a huge accumulation of moisture in the receiver dryer, to warrant replacing it after only 1.5 yrs.
Right? ;-)

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Any time you open an a/c system, you replace the filter/dryer. Your mechanic should know that and insist on it.

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I think he does know that, but he was trying to save me money by making it an option, if I chose to forego it. I thought I was going in there just to have my high/low side port schrader valves changed + vacuum + system recharge, so not too much money.
But then they found the condenser was where leak was from, so now we're talking several hundreds of dollars, and I was visibly disappointed, so he was trying to knock the price down a bit for me.

I'm going back in tomorrow morning to have the work done. I guess I will have the receiver-drier replaced too. I see now that it's recommended replace it every 2 yrs, so it is getting toward that time.

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I question the need to replace the accumulator or receiver/dryer whenever the system is opened. If there is still refrigerant in the system before it is evacuated, then water intrusion should have been prevented by the pressure of the refrigerant inside pushing outward through any possible leak area. IOW, water can't get in because the pressure pushes it out.
That said, the capacity of any desiccant in the system is on the order of 10 drops of water, total. If there is any humidity that gets in, as when a system is LEFT open, it likely will exceed the desiccant capacity.
I would check the price of a replacement condenser at several sites, as there will likely be large variance. The labor is minimal, but the system must be evacuated before replacement.
I would also obtain some Nylog fitting 'lubricant' to be used on assembly. It will keep the connections from leaking. My estimation(swag) is about 1/2 hour of shop time in addition to the time for evacuation and re-charge. That and a nickel.
tom

Taken from a auto a/c technical bulletin:





"The receiver/drier should be replaced any time the system is opened for service, and most compressor warranties require it. The desiccant is only capable of absorbing a certain amount of moisture, and when the inside of the system and/or the receiver/drier are exposed to the atmosphere, the desiccant can become very quickly saturated from humidity in the air. If this occurs, the desiccant is no longer effective, and will not provide future protection. Additionally, the filter inside the receiver/drier could be restricted by debris that may have been inside the system. This could diminish refrigerant and oil flow."

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Thanks for the info!
I had the repair done yesterday w/ new condenser & receiver-drier put in. Blows cold again now. AC is a must for living in the tropics with hot/humid summer weather just around the corner.

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