[Rich64N]

The good news is that my AC is finally working again after charging with ES-12a. However, I now have to run it all the time because the compressor clutch isn't fully disengaging when the AC is off, making a nasty scraping noise.

A bit of history. System had a slow leak, and had zero pressure for a couple of years. Empty. Preparing my AC system for ES-12a, I pulled the compressor to drain the oil. No oil came out, dry. Spinning the pulley, I heard a scraping noise. Hmm, maybe the clutch bearings are bad. So I pulled off the compressor clutch. Well, bearings were OK, so I cleaned everything and put it back together. Used a torque wrench on the end bolt to spec. No extra parts. All the shims back in place.

Before I removed the compressor, there were no noises from the compressor. But as soon as I removed it (no disassembly), the clutch was rubbing the pulley when I spinned it.

Watching the compressor with the engine running, and the ac off, I see the compressor rotating at a lower speed than the pulley (i.e., periodically catching), and making the "nasty scraping noise."

Any ideas? Maybe I need some more shims? It is great having AC again, but not all the time!

 

[trexse]

hi guys, very sorry to bring up such an old thread but my ac clutch is doing the same thing on my 85sdr. it scrapes the pulley when not engaged. does anyone have any idea on how to fix this? is there a way to adjust the clutch further away from the pulley?

 

[Gargravarr]

I'm gonna bump this thread too cos I've seen the exact same behaviour with my 1986. It's a problem for me as the system is bone-dry at the moment (can't afford the recharge, and it's been sitting in the garage for years). It's only done it once as I was about to leave a garage; I very nearly cut off the A/C belt to save the compressor as I know running it with no oil will destroy it. It settled itself when I restarted the engine and I haven't noticed it since.

My guess is that the spring return that pushes the clutch away from the compressor drive is weaker than it should be. Can anyone confirm this? If so, what's the fix?

 

[KJK_Texas]

The standard gap should be .016" -.028". It is adjusted by placing shims on the compressor shaft.