a/c clutch locking up - PeachParts Mercedes-Benz Forum

john420 · #1 06-29-2003, 08:34 PM

My compressor was replaced a little over a year ago and converted over to 134a at the same time by an indep. Mercedes shop. (Previous owner- I have the service records) Anyway, when I bought the car 4 mos ago, the a/c worked fine, but now that it's HOT it has quit. The clutch would engage at first, but make a clicking sound. I have not used it at all, but I tried again this morning and the clutch now completely locks up- squealing belt and all.

I know I don't stand a chance at getting the compressor covered under warranty since it wasn't mine at the time, but what I'm wondering is if the clutch itself can be replaced. I'm assuming it has a bad bearing. If so, how bad a job is that? Can it be done without breaking open the system?

Thanks in advance.

stevebfl · #2 06-29-2003, 09:54 PM

Since I haven't a clue about which compressor since I don't know which car, I can't say much about technique.

Does the locked up clutch unlock when you turn the A/C off. If so then your question is academic as your real problem is the compressor itself. If the clutch doesn't disengage and the clutch has to be replaced they can be removed without discharging if you have the tools and its the right model.

john420 · #3 06-29-2003, 10:06 PM

Sorry- I thought the user name gave it away. 420 sel, '87 model.

Yes, the clutch disengages when a/c is turned off at dash. There is no noticable noise from the compressor when idling with a/c off.

stevebfl · #4 06-29-2003, 10:14 PM

Its not a clutch problem then.

john420 · #5 06-29-2003, 10:45 PM

Can you suggest anything that I can try to find the problem, or is it likely time for yet another compressor?

stevebfl · #6 06-29-2003, 10:57 PM

Try turning the compressor by hand with the engine off. It should turn rather freely with slight binding on each stroke.

The way you describe the problem the compressor has had it. Unfortunately this type failure is about the worse thing that can happen as the system pumps its burned up pieces throughout the system as it dies.

Aside from the compressor one must check the whole system for contamination. If it is black inside, you better read up on black death and replace at least the condenser also.

john420 · #7 06-30-2003, 07:55 AM

Nope, it's very tight and hard to turn. Off to the shop I guess. Thanks so much for your help.