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View Full Version : After 20 years, I think the a/c compressor bearings are going



w261w261
07-31-2008, 05:39 PM
It sounds like little marbles rattling around, only when the a/c is engaged. If it were the compressor clutch, then it would do it all the time, right? So I imagine its the compressor bearings. How can I complain, it's the original issue!

I imagine those bearings are sealed, so there's no point in trying to squirt some pb blaster between the pulley and the compressor?

I'll drive it til it drops I guess.....the a/c works fine.

Thx

Ichiban
07-31-2008, 05:55 PM
Yeah, I say run it till it blows up. You can probably find a comparable, modern and cheaper compressor, and machine up parts to adapt it to your bracketry rather than shelling out bucks for an OEM replacement. Upgrading all the time.

LX-incredible
08-01-2008, 11:00 AM
I would try turning the center part of the clutch to see how the compressor feels. Check that the clutch isn't slipping. The idler bearing is easily replaced on the densos, even though most will try to sell you a new clutch. Doesn't sound like your problem though. What you might be hearing are the vanes or whatever meshing without sufficient oil. Mine sounded like it was on it's way out a 2 years ago. All it needed was a couple ounces of oil.

w261w261
08-01-2008, 11:34 AM
<< All it needed was a couple ounces of oil >>

Where did that oil go, exactly?

LX-incredible
08-01-2008, 04:54 PM
When you run the AC, it circulates oil throughout the system. The oil coats every surface and helps to provide a barrier for the thiner refrigerant. It is constantly being forced out from system pressure. When the AC is left idle for prolonged periods of time, the oil will eventually be forced out through the susceptible areas such as o rings, seals, hoses and loose fittings, resulting in in an increased loss of refrigerant. In climates where the AC is frequently used, the oil will always be between the refrigerant and those surfaces, and will be the main thing forced out... until the system runs low on oil. Have a look you will probably find a few fittings covered with dust that is clinging to the oil. Don't be surprised if the compressor seals are leaking a bit as well. Are you still running the original R12? Many times when a system is recharged the proper amount of oil isn't added.

w261w261
08-01-2008, 05:16 PM
<<Many times when a system is recharged the proper amount of oil isn't added>>

Hmmm, my ignorance of a/c technology is showing. When I bought the car in '01, I had the a/c recharged by a tech. That got me through until last year, when I just bought a a couple of cans of R12 (the old stuff, I know someone that will sell it to me) and had my mechanic recharge it. So he should also have added some oil too? How does that happen?

LX-incredible
08-01-2008, 08:51 PM
A little oil usually needs to be added with the refrigerant, as it can escape the system as well. Some don't like to mess with it because an overcharge can destroy the compressor, others because they don't mind charging your system once or twice a year. They make disposable oil charge testers, but I have never used one. I have done it both ways and can say that a proper oil charge will reduce the frequency of which a system needs to be recharged, many times by half or more. The pressure differential between the high and low side will usually also increase, as the oil helps to seal between the vanes. This will result in a more efficient system.

You can either use a charge hose or an oil injector. I never got around to buying an injector, so I use the charge hose. You can get by with filling the low side hose of your gauges with oil, reconnecting and using refrigerant to force it into the system. It might take a little longer this way, but it works.