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AC compressor died...

Started by 1980sdga, 11 June 2011, 01:27 AM

1980sdga

I mentioned it in my "On the road" thread but here it is again.

My AC worked great for about 200 miles. No problems, no complaints. I did get low on fuel and turned it off for a few miles but it started back OK.

On the way home I noticed it wasn't cooling. Checked and the clutch was slipping. It seemed to slip-grab-slip-grab. I shut it off when I saw what was happening.

I got home in the light and figured I'd give it one more shot and it made an awful noise so I shut it off.  The belt didn't squeal nor did the engine bog down.

Any ideas?

With my limited knowledge I figure:

Best case- AC clutch was slipping for a few miles and went out.
Worst case- Compressor sh!t the bed and filled the entire system with bits and pieces of itself  :o

I'll see if the compressor turns...

KenM

Jon,

Your diagnosis is about right, either the clutch itself is weak, which happens but is unusual, the magnet is very strong so if it's slipping you could have a warped plate, you won't be able to see it but it doesn't take much to

warp them beyond use. Check for grooves that have been carved into the clutch plate by a stone or something like that. Otherwise there is a restriction in the compressor, either it's overcharged and the discharge pressure

is too high or as you say she is on the way out mechanically.

Good luck,

1980sdga

Today I removed the compressor from the car (R4) and pulled the clutch. From what I can tell nothing is broken inside the compressor but the bearing that the pulley rides on seems to be shot.  I pulled the clutch and some debris fell out which I think was binding the bearing. Seems to have a lot of play as well.

I'm checking around to see if this is a serviceable part or whether I should bite the bullet and get a new compressor/pulley assy.

Hey Ken. I made some vids of what I found. Mind taking a look when they are uploaded?  Never mind the funny accent  ;D

KenM

That's good news, you can easily replace the bearing yourself with a few tools, just be careful not to pull on the plate when removing the bearing part, the slightest warp will cause it to slip when back in use and it will be shot.

Cheers,

1980sdga

Here's the saga...

These are the lines that connect to the compressor:



Nothing black or funky came out. No pieces of compressor insides. Just oil and dye which seemed pretty clean to me.

The compressor where the lines attach:



No debris there that I could see.

A video showing the "notchy" feeling in the pulley:

http://www.youtube.com/watch?v=9UNFMQdEzug&feature=mfu_in_order&list=UL

A picture of the debris that fell out when I pulled the clutch:

clutch

When I checked it out last night I pulled some similar wiry, seal looking material from between the clutch and pulley. It looked almost exactly like the semi-circle piece on the vice.

Here's where I am now:

http://www.youtube.com/watch?v=yqpqT_q8rS4

I didn't notice until viewing the last vid but it appears as if the friction surface of the pulley is running out a bit.  The bearing feels pretty loose as well.

Any thoughts on this? Looks like I at least found the problem, or A problem...


Thanks for the help Ken!

thysonsacclaim

That's interesting.

It's beyond me, but I am interested to see what the others think.

I hope it's nothing serious, though. I've got mine sitting in the garage now and I figured I should give it a through look-see before dropping it in.


Best of luck

1980sdga

Well, it appears that the bearing between the pulley that the belt runs on and the aluminum hub of the compressor is shot.  When I spin the pulley on the compressor the ball bearing unit isn't turning at all. The inner race is turning around the hub but the bearing is seized!

I'm actually considering it good news!  Everything else looks good so I think I'll just change the bearing and see what happens. I'm also going to change the drier out as well and have a shop re-charge the system.

The parts store had a bearing in stock but the OD was too big.  I guess I'll try to press the bearing out to get measurements.

The AC was working fine up until the clutch stopped engaging and then it seemed to seize.  I think my problem may be as simple as a bad bearing!

I also found that the nut that holds the clutch on was missing! The threads are rusty so I think it's been like that for a while  :o  Could be that during hours and hours of operation the clutch moved or began slipping and heated up the bearing causing it to fail?  Maybe the bearing was just old and dry?

KenM

Hey Jon,

Your third video tells the story, there is a lot os slop between the bearing inner race and the shaft. If as you say the inner race has been spinning because the bearing is seized you will need to check the shaft, it will be

scored but you'll need to measure if possible to see by how much. Check the measurement against the inner race of a new bearing maybe. From the look of the plates the clutch has been getting pretty hot not surprisingly

but the big issue is going to be the condition of the shaft, if it's too worn you could be in strife there.

Good luck, 

1980sdga

Thanks Ken!

When you mention a warped plate are you talking about the part to the right with the puller attached?



The bearing is pretty seized. I can't spread my fingers apart and spin the inner race and there is a lot of play between the inner race and the aluminum shaft. I figure if it spun too long it made a lot of heat  :o

Maybe I caught it in time.  I'll measure the clearance and let you know what I find. It's a pretty loose slip-fit now.

  I was at the parts store today and they had a bearing for an R4 compressor in stock. The ID looked right. It was a LOT tighter on the aluminum shaft than the old one. It seemed like it would be a light press fit but the OD was waaay off. 

I didn't have a lot of time at the parts store, I mainly went by there to return the tool I rented, but I'll measure in the AM and see if they have something that'll work. I also need to round up a replacement for my missing nut  ;D

Thanks,
Jon

KenM

Hi Jon,

Yes by the plate I am referring to the section you have on the right, the bit that is pulled in by the magnet when you engage the clutch. It doesn't take much to warp them but you won't see it, sounds like yours is ok if the thing has been working. You can see in your last pic the number of the bearing, stamped on the dust seal, that's the number you need to take to the bearing shop but take the bearing as well in case they need to measure it. Hopefully the inner hub is not too worn down, I should have used the term inner hub instead of shaft in my last post, might pay to have the bearing place mike it up to see how it compares with the new bearing. At least your compressor looks nice and clean inside!!

1980sdga

Here's a vid showing how much play is in the bearing:

http://www.youtube.com/watch?v=dGNJ4RLobHE&feature=mfu_in_order&list=UL

I have a couple of days off work so I'm going to try to get the bearing situated in the AM.

Jon

1980sdga

I discovered that the clutch surface of the pulley is concave  :(  I may have done it while removing the bearing which put up a fight...

I guess I need a new clutch assy. at least.

KenM

Hey Jon,

That's the video I was referring to, bummer if the clutch plate is warped, it's easy enough to do though, particularly with one that's stuck on badly. At least you won't have any trouble getting a new one, no idea what they're

worth though.

1980sdga

Well, a new clutch is over $100 and I can get a new compressor with clutch for $225 so I'm just going with a new compressor, drier and expansion valve along with converting back to R12 (maybe). R12 is still around here in the Southern US.

One of the reasons I'm considering converting back to R12 is because it runs at lower pressures than 134a (Correct me if I'm wrong about this) so it should be a little gentler on the compressor and other components.  The only thing that worries me is removing the valves on the compressor manifold. I don't want to screw it up  :o

I flooded the system with argon and plugged the ends so I hope it will prevent corrosion/moisture from getting in the lines while I round up parts.

Here's a pic of the oil I got out:



I filtered it through a towel while I gently blew argon through the system. It looks clean so I don't believe I've ever had a dreaded compressor or drier failure.

I REALLY didn't want to get into this  :'(  But I knew it was a possibility when I first started getting into these old cars so at least it isn't a big surprise.

What do you think about going back with R12?  About the only down side I can see is future availability and the expense.

Any advise on how to proceed?

jbrasile

Jon,

I like the idea of going back to R-12 with a new compressor and drier. I am just not sure if you should replace the expansion valve because the new ones come calibrated for 134 and I don't know how to modify it to work with R-12. Chances are that the one in the car has not been replaced so I would check that, try to clean it's filter screen and put it back.

Wise decision on a new compressor, if your system is leak free you should have perfect a/c for years to come.

Tks,

Joe