99: A/C compressor failure

Replaced entire A/C last year except for refrigerant lines. Got parts from Rock Auto. It's been nice and cold until earlier this week when it just stopped cooling at all. Pressures look good but clutch didn't appear to engage. Eventually concluded that clutch was trying to engage but compressor wouldn't turn. (Sometimes it squeals when engaging.) So apparently compressor failure.

My question is how can I determine if the clutch failed with no internal compressor failure or there is a problem on the refrigerant side of the compressor? In other words, how much do I need to do beyond replacing the compressor (again), like orifice, condensor, etc.

There's less than 10k on car since A/C was replaced and some of that was winter time driving. I bought a Four Seasons brand which has a 2yr 24k warranty. But I wonder if I should just eat it and get AC Delco. Recommendations?

Thanks.

First thing you can do, is grab the clutch plate and turn it manually(engine off, and not running, of course)......it should rotate fairly easily......if it doesn't, then you have a compressor problem....

Can't turn the clutch plate. I reckon that means the compressor is locked up.

New compressor is obviously needed and apparently the drier and orifice tube should be replaced. Should the condensor also be replaced due to potential damage from metal shavings?

Looking for air conditioner service advice.

Although the entire a/c system, except the refrigerant lines, was replaced a year ago, I can not get the compressor replaced under warranty because I do not have a receipt for a/c flush. I followed the FSM when doing the work and it does not mention performing a flush. I apparently didn't read the instructions that came with the third party (Four Seasons) compressor which specify performing a flush.

I've done some auto a/c work in the past, mostly with R-12 systems but some with R-134a. Have never done a flush and have never had a compressor fail.

What's the procedure for the flush? Can I flush with components (especially condensor and evaporator) in place? Does the flush remove all the PAG oil from the components? How much PAG oil to add to each component? So many questions...

I would like to do this myself because I think a shop would charge (at least) $800 - $1000. It shouldn't be that difficult. But I don't want to go through this again.

Guidance appreciated.

Whenever you have a compressor fail and it sends metal into the system, then a filter should be added into the system........

Between compressor and condensor?

You can remove the compressor and look into the discharge port- if blackened- then severe overheating inside has been going on- most likely from running low on charge-- if you see metal fragments inside- then yes- filter is advisable-- if clean as a pin inside- then something let go in your Four Seizens pump- and it is a clean failure--You need to do the autopsie....

Pulled the compressor off this morning. I don't see any visible signs of damage: No scorching, no metal fragments. Should I disassemble for better inspection? I connected the original compressor to seal system for the time being. (It hadn't failed but I had leaks I couldn't find so replaced the entire a/c last year when engine was out; had 200k on it.)

Given that orifice, evaporator, condensor, accumulator were all replaced, is it reasonable to just replace the compressor?

And I still don't know if I should flush it or not. If it is flushed, do I assume zero oil in each component and add oil as if new?

bcridd, can you provide guidance on my last post?

Inspect the orifice filter. If it's clogged with black gook, you need to flush the system. 4-Seasons brand compressors are sketchy quality at best, so I would suggest trying a different brand if you can find one.

Thanks, Rich, for the reply.

The orifice filter was covered in black gook. I flushed all lines, condenser, and evaporator and more black gook was removed. What is that stuff?

I installed new AC Delco compressor, dryer, and orifice. Added 6.5oz PAG46 to suction line so that, with the 2.5oz that comes in the compressor, a total of 9oz of PAG46 was in system per spec. I evacuated for a couple hours and the system held vacuum for about 24 hours; vacuum decreased slightly during the first hours then stabilized; I reckon that there may have been a little leaking at service ports where manifold gauges were connected. I charged with 30oz R134a. Hoping I did everything right and this a/c system works for many years without issue; time will tell.

The black gook is compressor material that let loose and got ground up and spit out when it failed. Always make sure you add some oil to the compressor before installation, then roll it over by hand 15-20 turns to get it in there as most new/reman compressors come without oil. Otherwise, when you install the new compressor, it chews itself up until oil gets to the reciprocating parts.

Thanks, Rich. The AC Delco compressor came with 2.5oz PAG oil in it. A former mechanic at AutoZone said he put the balance of system PAG oil into the suction line before sealing it up, which I did. Then I hand cranked the compressor a bunch of times (about 30 revolutions).

Haven't had much use for A/C recently but the defroster works quite well. I guess next summer I'll know if problem resolved.