The internals of the compressor. Now we know what rotary vane means. This comp is at about 7 yrs old. It started making a vibrating noise. At the time I thought, I’ll add oil as soon as I can get to it. I guess I wasn’t soon enough. Several days and a couple of long drives later, it stopped cooling except at highway speeds. Hooked gages up and I could see zero difference from HI to LOW, except when I revved the engine. At that point I got about 40-60 psi differential. Hmmmmmmmm...what’s up?

Called a friend..........."bad compressor. Do you think the comp locked up?"

----No it turns free and cools at high speed. I stopped using it to keep from "black death".

"OK just change out the compressor and the drier. Anything else is extra work.. " He was right. But I did it anyway.

Took it to a vo-tech school and got them to reclaim the freon for me. Took out everything out but the condenser, and flushed everything period. Saw no sign at all of an oil leak. All of the oil must have come out of the system when they reclaimed the freon. The whole system was spotless before I flushed. A little bit of oil came out of the evap. Not much. Used mineral spirits on the condenser and evap. Blew out the hoses with air. You’d be surprised how long the evaporator keeps dripping mineral spirits. That stuff don’t evaporate that quickly.

Autopsy on the comp showed that each vane was scratched on the hard coat, one side only. It did have some oil remaining in the comp after the freon was removed, so I don’t think it went without. That was the only damage I could recognize, but this is the first one I’ve seen . I didn’t really know what I was looking for. The vanes slide out of the rotor slots by centrifugal action and/or pressure difference. Thats why it worked at high speed , and not at slow, I suppose. There are no soft goods in the whole darn thing except the lip seal and body seal o-rings. Was I surprised? The tips of the vanes are not coated, very soft metal, easy to sand down. I guess this helps lap a seal with the barrel. The shaft lip seal surprised me. I have never thought highly of them until now. It is well made though, and it only has to seal as high as suction pressure while running. The lip seal area is ported/vented back to the suction, so it doesn’t seal discharge pressure when running, even though it is on the discharge side of the comp. You can see the rotor, barrel , lip seal , valves, and the front housing of the comp. The barrel is oblong, rotor rides in the barrel, and as the rotor turns, the vanes follow the contour of the barrel to make pressure. Forgive me for being simple here.....I had to repeat this to myself a bunch of times before I thought I had half-a-handle on what might be happening with this darn thing. In the background right is the clutch...... I gave it a destructive test also. The other link is a closeup of the rotor in the barrel. I hope they will open.

http://http://photos1.blogger.com/blogger/6128/3321/1600/P7200004.jpg

http://http://photos1.blogger.com/blogger/6128/3321/1600/P7160006.jpg

 

Looks like lube failure to me. Not enough oil. Removing the freon does not normally remove oil from system.

Ken

 

all oils eventually break down and dissipate from a closed system, the higher level volitiles evaporate and leak out first.
all seals leak
the old mineral oils were the worst for breakdown and higher level of volitiles.
even the esters, PAG's and PAO's breakdown from heat and pressure over time. they do not have as high levels of volitiles as mineral oil
all auto a/c systems should be drained, flushed and correct new oil/refrig. added every 1000 hrs of use. the under hood heat is a killer on compressors

 

Enjoyed the write up. The compressor is simpler in function than I was expecting. Thanks for posting.

 

The heart (slash pump) of the air conditioning system, the compressor. If this was cleaned with a solvent and oiled up, theres a slight chance it might still work. Compressors do alot of work. Start up, severe duty, and constant cycling do most of the harm to em. They also have to pump gas and liquid. Nice pictures

 

Does that compressor have the hose manifold mounting on the back or on the top? Trying to figure out if it's the older type or the FS10.

 

KD,
This isn't out of an Aero, but it is a Calsonic DKV 14V. The suction and disch hoses are totally separate. Suction is a one bolt on the top side of the back plate of the comp. Discharge is one bolt on the front.
Does an Aero have a rotary vane or some other type? I had read that Ford's were bad for compressor lock ups and then dispersing trash thruout the system.
My Aero had an A/C hose leak. I don't know if I did good or bad, but I put stop leak in it and it seemed to have worked well. This was a couple of years ago. I just hope I don't have to open it up.

I see that the double "http" really screws up trying toi get to the pics.

 

FS10 Ford type swash plate compressor



Black Death

 

Ken,
My first thought was the same thing --lack of oil. I pulled the all but the condenser out of the car. No sign of oil leakage anywhere. It was cooling great up until "all of a suddden", .......and at highway speeds, it was still cooling. So I felt like I had a charge. Could have been low. But absence of oil soaked residue/dirt/crud right at the point where it leaked out has me baffled. Even around the seal/clutch it wasn't dirty enough to make me think it leaked there. As for the oil going with the freon, my reasoning was when they pulled the freon , most of the oil was with the liquid charge. As they started pulling, it boiled vigorously helping to carry the oil with it. On a slow removal, like a leak, oil may not go with the freon so readily. There was a small bit of oil left in the comp and on all the o-rings, and it was very clean. The scratches on the vanes are on a chrome (or other hard) plating. I have seen them smear like that before, but as you say it was lack of oil, poor application of the plating, or high load.
What is more amazing to me ...and this is just a pencil exercise that may be wrong but ...this compressor has about 100,000 miles...avg 40 miles /hr....at 2000 rpm.....and what looks like 1:1 to the main pulley. And where I live (near Baton Rouge) the A/C is needed over 50% of the year. If the compressor cycles 1/2 the time then these vanes have made an amazing 50 million plus sliding cycles--in and out of the rotor slot, which is a metal to metal slip fit! ...it doesn't seem possible. If I am off by a factor of ten, and it is only 5 million, it is still hard to accept. I gotta be wrong just don't know where.........Check my math!