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'87 300DT A/C Clutch R&R 2x!

Can someone please tell me whether this is due to a poor-quality remanufactured clutch, or a faulty a/c compressor:

My '87 Mercedes 300D Turbo A/C clutch went bad: it wouldn't engage but at least didn't jam the pully which still spun freely when the clutch was disengaged. I replaced it with a remanufactured Autozone clutch. It worked for a month of use. That last one went bad and actually seized the pully, breaking the serpentine belt in about 4 seconds. The mechanic said when he was replacing the clutch the first time that when he spun the compressor by hand there wasn't abnormal resistance. As I say, this time when the clutch went bad it broke the serpentine belt because it wouldn't freewheel the pully when the clutch was disengaged. This could be because the bearings in the remanufactured Autozone clutch were never replaced (or are terrible quality) and the entire assembly just melted together, or perhaps the compressor went bad and the clutch went bad together.

Option 1: It is $650 parts and labor to replace the compressor w/ clutch, evac and fill the system.

Option 2: It is $150 labor to replace just the clutch, as that previous clutch is still under warranty so there is no other parts cost with this option.

I don't want to spend the $150 on the 3rd clutch that is likely to burn out because of a faulty compressor.

So do you think it is a faulty compressor, faulty clutch and a properly functioning compressor, or faulty compressor and faulty clutch?

Thanks! Michelle

Reply to
Michelle
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Mmmm... I have the same delimma with mine... I think my clutch is bad because it whines so loud when engaged... especially at highway speed. I have yet to tackle by repairing it.

We can get remanufactured compressor for $250... so I just want you to be informed.

Reply to
Tiger

It's clear that something seized!

Can you turn the compressor? Did the A/C work before the belt broke?

I suspect the clutch's bearing for if the compressor seized the clutch may have at least slipped and burned out, not instantly broken the belt.

Reply to
T.G. Lambach

Yeah, there is no way the clutch alone broke the belt...

The compresor must have either siezed or hit a bump (so to speak), or some other accesory did the damage.

Even if the clutch stuck in the on position, the belt should have kept running,

Marty

Reply to
Martin Joseph

Thanks all! It was a bad compressor. The clutch had just been jammed into the engage position and wouldn't disengage until knocked with a hammer.

The compressor ran out of oil and was ruined. I had given it an oil charge a month ago (the compressed 134a/oil mix can, not the ester bottle of "suck it in" lubricant). Why don't these things have a little dipstick or other indicator to let you know they are low on oil? How frustrating! There were no signs of leakage, or maybe there were signs but I didn't check in the right places.

How often should you charge a system with oil to avoid this expensive repair?

Reply to
Michelle

Actually you shouldn't have to add oil in the first place... because the refrigerant itself has oil... like 2 oz for every 13 oz of refrigerant.

Oil doesn't get sucked out by vacuum when you evacuate the system... it is drained when the unit is removed from the car and worked on... It is possible this mechanic removed the unit from your car and did not replenish it when he put it back.

Reply to
Tiger

That compressor that went bad was the original, so the mechanic didn't err. The compressor was bone dry, so the original oil, the oil charge from a month ago, as well as the "oil in the freon" went somewhere, but where?

The oil getting sucked in is what I was talking about, when you add oil to a system from a non-pressurized Refrigerant Ester Oil bottle rather than a pressurized "oil charge/134a" mix can. A system will suck the non pressurized oil in from the bottle.

Reply to
Michelle

There has to be oil in freon itself so you can't assume that just by filling with frigerant, it will supply oil... that's not the case.

Reply to
Tiger

can someone recommend decent tires for this vehicle.

Reply to
300DT

YOK AVID TOURING

Reply to
Darrell

Goodrich Traction T/A's. Just put them on my 300SD and very happy with them. Excellent traction on wet conditions, good dry handling and ride.

Reply to
Chet Hayes

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