I'm pretty sure the compressor itself is okay; clutch is slipping/squeeling mostly only at low rpms and around corners, and the system is still cooling really well. My main questions are:

1) do you have to evacuate the system and remove the whole compressor to do this job? If so, I may just go whole hog and get a new compressor anyway, since the car does have 250k on it and I can always keep the old one for rebuild/as a spare.

2) clutch removal using the bolt holes looks simple enough, but are there any issues with re-installation, especially regarding the shaft seals? I haven't been able to find any description of this job online, so I'm still uncertain about how the clutch attaches to the shaft and how everything goes together.

If anyone has any tips/advice from personal experience, it would be most helpful!

I replaced the clutch on the A/C compressor of my 960 without removing the compressor. I would assume the procedures are similar for the 940. The main trick was getting the tool to remove the circlip into the recessed opening of the pully, since on the 960 space between the pulley and radiator is limited. I was able to use a mirror to see and worked backward (so to speak) to get the circlip removed.

The other trick was to slide the clutch off the compressor shaft. After removing the bolts, it's a press fit that normally requires a puller to extract. Since I didn't have the room to put a puller in the front of the clutch, I carefully pried from the back edges of the clutch to work it off.

This certainly isn't a recommended procedure, but I didn't want to have to open my A/C system and have to recharge it. So replacement of the A/C clutch without removing the compressor is possible - just a pain.

There were no shaft seals involved in the re-installation, since the compressor shaft is sealed in the compressor itself, and the clutch assembly is external to the seal.

Please note that the tolerances between a clutch that is engaged and one that is released is very small. There is a little washer acting as spacer in the assembly whose presence is critical to having the correct tolerance. If you forget to put this washer back on reassembly, your clutch will be permanently engaged. Ask me how I know.

Good luck with the project!

Dear Benfingland,

May this find you well. I have the Volvo Tech Manual (TP8701201: Climate Control; 700/900 1982 -; edition of November, 1995).

This manual does not cover the Seiko Seiki compressor (Model SS121D5S / VOLVO Part #6841207) used in many 1993 and later 940s.

The earlier compressors (e.g., York, Sanden, Diesel Kiki/Zexel), generally can only be worked-on when placed in a workbench vise.

Some specialized tools, e.g., 9995596 (counter-hold) and 9995597 (puller, for clutch plate) are needed.

Hope this helps.

Yours faithfully,

Spook

Thanks, Spook - that's just the info I needed. Having to buy the extra tools, along with the strong probability that I'd have to pull the compressor anyway, will definitely make me go with whole compressor replacement - especially factoring the car's mileage into things. Thanks again for this most useful input!