A/C Compressor heading south

[Al 96 Ram Air T/A]

Well, as luck would have it, I think my compressor is on the way out. I'm still 'reassembling" the supsension on the car. Spent a few hours cleaning up the rust on the lower control arms to paint/prime, but noticed a bit of oil on the front of the motor. One is leaking from the seal around the timing cover...no big deal. Been weeping for a few years. Never enough to register a drop on the dipstick.

The other is new(er). Noticed some oil around the a/c compressor. At first I though maybe one of the lines was leaking. However, I'm pretty sure it's leaking out of the snout around the clutch and maybe from the body seals. Anyway, it still works fine (ice cold) but you know what they say, where oil is leaking, so too is gas. If not now, soon anyway.

My concern is that once the compressor tanks, it'll frag into the system and I'll be replacing more parts. I'm thinking in the spring, I should replace the compressor with a new/remanufactured one. I'm not positive, but I think replacing the accumulator may be warranted as the dessicant is probably spent.

What do you guys think? Anyone done this yet? Any preferences/brands to look for/avoid? Is a remanufactured one safe to use or should I go new?

I was thinking I can replace the old parts then take it to a shop for a pump down and refill.

[MN6WS6]

Go with GM all the way. I am a parts guy, and I went through this same thing on my bird and my Astro van. Do NOT buy a compressor other than Delco or it's derivatives. I have talked with several AC shops, and they all agree that on a GM vehicle the only compressor you buy is GM. You will have problems, and the amount of time you spend working on the car replacing parts is not worth the money you saved buying them. While you're at it, you have to replace the orifice tube/expansion valve and the dryer/accumulator for compressor warranty purposes. Also, you need to go ahead and get a high side pressure switch (on the back of the compressor, some new GM compressors do not come with it) and the low side switch. These two switches only amount to about $50 or so, and either one of them can leak freon faster than a blown seal any day of the week and twice on Sunday. I know because it happened to me. The system will always find the weak link, and my van was a daisy chain of blown parts. So on the bird I went ahead and bought them all and have not had an issue.

As always, call Dal or Jason (I think) at the always popular "GM parts for employee price to everyone" stores.

[Al 96 Ram Air T/A]

So, do you think the system needs to be flushed? Assuming I replace it before the compressor detonates, the system is running fine now. I was thinking after replacing the listed parts, I'll only need to have the system pumped down to remove moisture and then refilled.

[Joe 1320]

There's really a few ways you can look at it. If you replace the compressor before something grenades, you'll likely not need an oriface tube. You can get by with just a compressor and accumulator. I've done that a few times and everything has been fine for many miles.

Now to do it right, you should replace everything that was previously mentioned and you're better off if you plan on keeping the car for the duration.

[Al 96 Ram Air T/A]

Great info guys...thanks!

[fastTa]

MN6 gave some good advice. The orifice tube and dryer/accumulator should always be replaced when replacing or rebuilding the compressor. The orifice tube is a $4 part, and the dryer/accumulator is roughly $30-$35. So for less than $40, you have peace of mind.

Additionally, you need to always pull the orifice tube anyway. That's the best place to inspect for "junk" in the system. If there is a bunch of junk in the orifice tube, you can bet the condenser is full of it as well.

[Ponyrider]

I have all items off my 95 z28. I remove them for weight nothing wrong w AC or tubes or condensor [

QUOTE=Al 96 Ram Air T/A]Well, as luck would have it, I think my compressor is on the way out. I'm still 'reassembling" the supsension on the car. Spent a few hours cleaning up the rust on the lower control arms to paint/prime, but noticed a bit of oil on the front of the motor. One is leaking from the seal around the timing cover...no big deal. Been weeping for a few years. Never enough to register a drop on the dipstick.

The other is new(er). Noticed some oil around the a/c compressor. At first I though maybe one of the lines was leaking. However, I'm pretty sure it's leaking out of the snout around the clutch and maybe from the body seals. Anyway, it still works fine (ice cold) but you know what they say, where oil is leaking, so too is gas. If not now, soon anyway.

My concern is that once the compressor tanks, it'll frag into the system and I'll be replacing more parts. I'm thinking in the spring, I should replace the compressor with a new/remanufactured one. I'm not positive, but I think replacing the accumulator may be warranted as the dessicant is probably spent.

What do you guys think? Anyone done this yet? Any preferences/brands to look for/avoid? Is a remanufactured one safe to use or should I go new?

I was thinking I can replace the old parts then take it to a shop for a pump down and refill.[/QUOTE]

[CDJr]

Im gonna go out on a limb here, being new here and all, and I certainly hope this doesnt come off the wrong way. But Im not sure I understand your reasoning for wanting to change out your compressor, Al. A refrigerant leak wont leave anything more than a damp area immediately at the spot its leaking, and even if it was leaking enough to leave an oily residue, it would just about hafta leak enough that it would no longer be cooling. As far as changing it so that you wont hafta change other components in the event of a failure, well, if you change the compressor and accumulator, thats pretty much the major components that would need changing if it DID fail.
I would suggest finding out if its actually leaking, and where, before I just started changing out parts. It could be that you do have a leak around the compressor, but it may not be from the compressor. And if its still cooling, then it evidently hasnt leaked much. Hope this helps, Al. And I hope my opinion doesnt seem disrespectful to anyone

P.S. Does this count as my official introduction? lol

[fastTa]

The easiest way to find a leak is to add some flourescent dye to the low side and use a black light to look for leaks. They will usually be very obvious. Just make sure you keep the static low side pressure close to the ambient air temp or around 30-45 PSI while the clutch is engaged.

[CDJr]

Ya, I agree with changing the accumulator/drier, of course I wouldnt drain the system just to change it, but if youve gotta evacuate it anyways....
Those compressors are that prone to leaking out of the case, Bruce? Which one did they put in that gen?

[Joe 1320]

Ya, I agree with changing the accumulator/drier, of course I wouldnt drain the system just to change it, but if youve gotta evacuate it anyways....
Those compressors are that prone to leaking out of the case, Bruce? Which one did they put in that gen?

Don't know if it's "prone" but quite a few 3rd generations I've run across when I was in the buying mood all had issues with the A/C. Guess what part? The compressor case itself.

[MN6WS6]

I think we have a bit of a misunderstanding as to his problem. He has an oil leak issue, and on 134 systems the oil is pretty much contained to the compressor itself. R12 suspended the oil throughout the entire system, which is why you are supposed to flush the AC system when you convert it over. But since the oil is restricted to the compressor and about half of the high side line (if that), the oil can only leak from the compressor itself. That's why you have to put dye into 134 systems to find a freon leak. The dye suspends in the freon, and leaks out at the leaking point.

Front compressor seals going out is nothing new. On cars with the compressor mounted high you would get an oil line on your hood and a streak of oil across the engine bay in line with the back of the AC clutch. My Caprice, Oldsmobile, and my brother's full size Jimmy all did this. On my 96 bird I didn't see it, because the compressor is on the bottom of the motor and you would have to get under the car to look for oil seepage because of all the other stuff in the way before you get to the hood.

[fastTa]

It's also common on these compressors for the head bolts to leak. You just have to pull the clutch/clutch drive in order to remove the headbolts and put on some non-metallic thread sealant/anti-seize compound.

[fastTa]

Make no mistake about it, the mineral oil lubricant (5GS) used in R-12 systems IS NOT compatible with the polyaklylene glycol (PAG) lubricant in R134a systems. The ASE HVAC and RRR courses stress this very heavily.

You MUST completely evacuate all of the mineral oil from an original R-12 system before converting it to use R134a. Additionally you MUST replace the original R-12 dryer/acculmulator, that used R-12 specific desiccant pellets, with a R134a specific dryer/accumulator that uses R134a specific desiccant packs (XH7 or XH9 desiccant).

The PAG oil used in R134a systems will turn the R-12 specific desiccant pellets into a slugde that will eventually clog the condenser, orifice tube/expansion valve, and evap core. Conversely, the mineral oil used in R-12 systems will destroy the R134a specific desiccant packs (XH7 or XH9) and render the R-134a dryer useless.

Also using R-134a in a original R-12 system will raise the head pressure much higher and create more heat in the compressor and system.

Because of this and due to the chemical composition of PAG oil, AT MINIMUM the old petroleum based o-rings are no good with R134a. You are supposed to use the thermo-oxidative resistant Hydrogenated Nitrile Butadiene Rubber (HNBR) o-rings with R134a. Whether or not a R-12 compressor will survive with R-134a in the sytem is a 100% gamble. Sometimes it survives, sometimes it doesn't.

All of the above is well documented as a standard procedure in automotive professional books, ASE certification, and software when converting R-12 systems to R134a.

[CDJr]

Very good info, Kevin.