My '85 MGM, "Maisa"

[Rodentkiller]

Arguemann start saveing the money for a new engine and don't worry about the A/C untill you rebuild or get new engine as far as a A/C Compressor buy a new one, from Rock Auto.

[gadget73]

if the compressor locked, it definitely puked trash out. if its the old tube and fin condenser, it will probably flush. Expect the orifice tube to be clogged, and any time the system is opened the drier should be replaced.

For me, if the AC doesn't work, the engine won't wear out either because I'm not going to drive it.

[Arquemann]

if the compressor locked, it definitely puked trash out. if its the old tube and fin condenser, it will probably flush. Expect the orifice tube to be clogged, and any time the system is opened the drier should be replaced.

For me, if the AC doesn't work, the engine won't wear out either because I'm not going to drive it.

Yeah, I'll order a drier/compressor/orifice tube kit off RA when the time comes. Condenser looks like it could be factory, the compressor has a reman tag and says its r12/r134 compatible and the system has been running r134 for the last 3 years. Compressor has sounded just as awful the whole time, a loud "krrrrrrr".
Hopefully the system isn't completely full of crap, otherwise just a flush might no be enough. If I have to start replacing condersers or evaporators, costs will rocket.

I'm looking at component kits for the MGM and Caprice, those plus shipping is about 550€. Slap on 24% VAT and ~3% Duty and cry.
Locally, just a compressor for the MGM would be 400€...


I've come to terms with the clacking bottom end. It's not a problem now, I'm not dealing with it now, and according to some people, it might not be problem for a long time. I'll keep on driving until shit hits the fan or the oil light comes on. I'll put on an oil pressure gauge to see where it's at idling. That might tell me how long the problems will stay away.

It's a bit annoying that the AC crapped out so far into the summer, fixing it now might get me use for it for some weeks anymore, autumn and cooler weather is just around the corner.

[gadget73]

evaporator won't be clogged, the orifice tube will stop it.

The condenser is easy if its the old one. One path through it, so if you flush it both ways it should be ok so long as you flush it enough to get all the trash out. I'd also flush the line between the compressor and condenser, if its got one of those little can muffler things that can hold trash in it.

some compressors are noisy, some just aren't. Possible it suffered damage in a prior life and it finally just gave up. Usually its lack of oil that kills them but I have a reman on my Towncar that sounds like a dying air raid siren and it sounded that way from the minute I installed it. That was probably 10 years ago.

[Arquemann]

Looks like a tube and fin cooler to me:


Also it seems that the compressor seals are compromised, the compressor is hissing quietly and there seems to be very little pressure in the system. I tried the valve on the compressor side with a knife tip.
I was going to empty out the refrigerant in an environmentally responsible manner, but seems like a total waste to drive over an hour and pay to get the last little fart of refrigerant evacuated...

Should I go with a Four seasons reman compressor or GDP new unit?

[friskyfrankie]

Should I go with a Four seasons reman compressor or GDP new unit?

What's the price difference for both?

[Arquemann]

Should I go with a Four seasons reman compressor or GDP new unit?

What's the price difference for both?

Like ten euros in favor of the reman kit...
-Reman is Four seasons which I would consider a reputable brand
-Reman compressor would be black
-GDP is chineeeese made

-GDP unit would be new-new
-GDP kit comes with an O-ring set

[friskyfrankie]

From personal experience and that of fellow AC folks, Four Seasons seems to be "hit or miss". Is this for the '85 GM? Just want to make sure. If you have little choice and go with Four Seasons, you may want to invest in a new one as opposed to reman, if the price difference is not too much and you can afford it.

[Arquemann]

Anyone interested in some mediocre air-conditioning carnage?

I'll start with removing all the parts. I have no clue on what has been done to this AC system in it's history. The compressor has been remanned a long time ago, and also has leaked a long time. Atleast one AC line has also been replaced, two others have Ford P/Ns on them and look older.
Many of the hose connections had some wet, rusty grit on them, especially the connection on the drier/accumulator.



The orifice tube isn't doing too well, but no big or shiny chunks, so most of that might've been there a while.



Well, I'll be sure get the condenser flushed properly, evaporator too.
I think I'll try to get a couple of the AC lines pressure tested, they have crap built up near the crimps and I don't know if they're leaking or the crap is from somewhere else. One is expensive at RA and the other isn't even available.
Though the AC has worked for two summers without any obvious performance degradation.

[Arquemann]

Part 2: compressor dismantling and an attempt at diagnosis.

The clutch got hot enough to blue the clutch surface and to make the powdercoating bubble...



The compressor is actually somewhat simple (compared to my expectations), there's an eccentric shaft which moves 3 pistons back and forth:
The pistons are "suspended" by 2 ball bearings which ride on the shaft on small copper coated pedestals. Said pedestals have very little or no copper coating on the friction surfaces, most were severely worn.



One piston looks like this, edge of the bearing "cup" has broken off.



All the pistons had major wear on the vertical surfaces between the bearing cups, I don't understand what is supposed to keep them from spinning in their bores and contacting the eccentric shaft, centrifugal forces maybe?



Both needle thrust bearings were fine, no marring or anything really.



Everything you and I see is kinda darkened and not-very-oily...

My theory:
The compressor has been leaking oil for a long time, which probably caused some unwanted dryness between the bearing pedestals that ride on the eccentric shaft. And that's how things got super hot. Friction and heat caused one of the piston cups to break and let the bearing, pedestal and broken off piece bounce around inside. That's when the thing went and locked up completely. The pedestal on the 4th photos is completely fused to the shaft, I don't understand how that happened...
Overall I severely dislike the lack of glitter and crap, considering how worn many of the moving surfaces are.

[gadget73]

agree it looks like a lack of lube issue

I had a 4 Seasons reman on my car, I think it gave me 3 or 4 years before the seals failed and it leaked everything out the front. I had OK luck with the store brand generics I used on Chevys, no idea how their FS-6 compressor is. All of it came from China.

[sly]

Third compressor was a charm on my 93. The 88 I had still had the original compressor but a replacement clutch. as with all things made aftermarket. Your mileage may vary.

[Arquemann]

I ordered the GDP compressor & component kit.
She's going to a shop specializing in AC on the 5th, they'll flush out the evaporator and condenser, put it back together and fill the system. They even have the R134a conversion fittings, so I didn't have to get them myself.
I'll have to mock the hoses up somehow so they won't have to figure out all the routing.

Also ordered the kit for the Caprice, that mess I can get done at a basic (more local) shop, since that's just replacing old parts and filling it up with R134a.

[Arquemann]

The new compressor says it's prefilled with 3oz of pag oil. Is that the full capacity for the whole system?

[DerekTheGreat]

...For me, if the AC doesn't work, the engine won't wear out either because I'm not going to drive it.

Same here, least not in the summer or late spring.