A.C. Compressor Problem, Or Clutch?
 

1984 300SD

Compressor (Harrison Mod#320) R4 type(?).

Compressor works O.K. for cooling, but makes very noisy metallic type noise,

My quandary is: Is it the compressor or the clutch that is causing it.

To get rid of the noise, I took the easy way out, for now, by removing drive belt. But I would like to fix it, or have it fixed.

I don't wish the expense and work of replacing the clutch just to see whether that's the answer or not.

Is it possible to make a definitive determination as to which is the problem, or is this a matter of being an experienced A.C. technician. :confused:

Spin the idler pully on the compressor by hand. It should move freely, with out noise. If you feel resistance and hear some noise that could be your problem.

Spin the clutch and compressor by hand in the direction the engine spins. You should feel some resistance since you are spinning the innards of the compressor as well. If you hear or feel grinding, as you turn it, then it is your compressor. The Harrison compressors are known to go out. Seems as if GM engineered them that way. Remember GMC means General Mechanical Crap.;)

The clutch can operate electrically with out the belt, and you can then turn the whole assembly by hand.

Put that belt back on and make sure its good and tight. For some reason, if the belts on these compressors aren't really tight then they make a noise like marbles bouncing around in a metal can. I've experienced this first hand on both of my cars. They made that sound at idle with the compressor engaged. Tightening the belt made the noise go away.

Does the noise occur with the A/C engaged or without. With the A/C OFF, the clutch on the compressor freewheels on its own bearing. If it is noisy with the A/C on and it's not the belt slapping, then the compressor bearings or internal other parts are shot. If the compressor is gone, DON'T use the A/C at all. The disintergration of anything internal on the compressor WILL contaminate the whole system. If you replace the compressor, replace the receiver drier also.

Concur.

The R4's are notorious for making awful noises, but make sure the belt is tight and check your pressures with some A/C gages. Yes replace the dryer and expansion valve when you change the compressor.

I am doing another A/C job on an '85 coupe this weekend. Lots of greasy fun:(

Here is how to do your other A/C items if you need to:

http://dieselgiant.com/repairyourac.htm

A.C. Compressor problem or clutch ?
 

A belated thanks to all who replied . Anyway, I had the belt re-installed and with the A.C. operating, I have the same old noise. With the A.C., switched off, I had the same noise.

What do you think: the clutch or the compressor, or both?

My Indy. mech. has an A.C. Precision Parts rebuilt compressor, But
the O.M. plate was removed. The Part number is AS 001796. I emailed them on July 15th., quoting their part number seeking info. on the original type, but I've had no reply ( snet another message to them to-day ).

Assuming this is a perfect fit, what ought to be done before installing it - I mean specifically flushing it out, etc., and filling with mineral oil.

All you valued help appreciated.

Padraig :confused:

Since the same noise is there with the A/C off (but the pulley turning), I'd say pulley bearing. Not uncommon.

Compresoor or Clutch
 

That's what I think,too.

Just musing, I wonder if a new clutch - if I can get one - can be installed without removing and benching the compressor. The reason I ask is if it is possible to do that, then I wouldn't not have the expense of replacing Receiver/Dryer and vacuum system, etc., etc.

Anyone know the answer?

There's not much room, but it could be done. The clutch plate comes off, then a circlip?(NOT the inside one for the shaft seal), then use a puller. Because of space, may need the special clutch puller(UL in case):
http://www.amazon.com/gp/product/B0002T5PRW/ref=nosim/102-6371893-9967308?n=228013

Sounds like you have a a/c compressor clutch issue. The HVAC manual shows how to replace it. Tools can be "borrowed" from AutoZone.

Anyway, I replaced the compressor on an '85 300D today that I had installed a new AC Delco compressor on a year ago (r12). The clutch was locked up to the point that the belt would not turn it. The compressor itself turns freely.
I think you have a bad compressor clutch.

Just FYI - On my 1983 300SD.
Did not want to recharge whole system just for a clutch bearing.

Did the clutch bearing, and the magnetic coil also.
Did not have to remove anything from the front (no hoses, radiator, oil cooler, etc).

Did need clutch puller, used a two arm puller for magnetic coil.

Used the threaded clutch puller to reinstall coil and pulley.
Made collars for pressing on the parts from PVC tube.

From what you wrote, it seems a repair kit can be had for the clutch - if so where did you get it?

From what you wrote, it seems a repair kit can be had for the clutch - if so where did you get it?

The magnetic coil (which not everyone will need, mine got chewed by the pulley) and the bearing (which is pressed into the pulley) can be purchased
separately.
GM dealers have them, but want more than a new compressor.
If you can locate a compressor rebuilder they may be able to provide them.

I got mine by chance through Ebay, $20 for each piece (quite a deal).

I would have purchased a compressor just to pull the parts off of it.
It would have been cheaper for me to do this than to remount the new compressor and replace the drier, expansion valve, evacuate and then recharge.

Does anyone know from experience that the A/C clutch removal tool that jbaj007 references will fit without removing the radiator?

I had a smoking clutch when I got home today, and I have some idea that it draws too much current.

Ken300D