Hello again all, made a lot of headway with my air conditioning, but there's still one more problem

The clutch for the AC on my 97 960 (Auto ECC) cycles, 2 seconds or so on, 2 seconds or so off, repeatedly, several times until the clutch fuse finally burns. Any ideas?

I figure that the coil on the clutch needs to be replaced, but i'm not completely sure. I'd like to know a little more about the procedure before i start dismantling the thing, (it's in a pretty confined place, and i don't want to open the system).

The way I understand, you remove the 10mm bolt in the center of the clutch, pull off the clutch, remove the snap ring on the shaft, press off the pulley, remove another snap ring, then remove the coil.

Is this correct? has anyone ever done this before that could shed some light, or maybe a diagram (IMG:style_emoticons/default/wink.gif)

Thanks in advance for all your help, you guys are the best!!

Myself and one of my best friends took to replacing the clutch on my zexel compressor today, and boy did we learn some stuff!

REMEMBER TO FOLLOW ALL LOCAL AND FEDERAL LAWS REGARDING AIR CONDITIONING CHEMICALS WHEN DOING ANYTHING THAT INVOLVES AN AIR CONDITIONING SYSTEM. Because changing the clutch on this vehicle doesn't require opening the A/C refrigerant system, we were able to complete this project, but any situation where the system must be opened should be left to a licensed, certified professional. A/C work performed incorrectly can be dangerous to ourselves and our environment. Please be careful.

In short, we changed the clutch with the compressor on the car, and while it was a little bit of a bear, it was nothing impossible. learning as we went, the entire thing took about 7 hours, with detailed instructions, it should be much shorter. My vehicle has a zexel compressor, which can be identified by the sticker that says ZEXEL, but also by the look of the clutch, which has 3 circular springs on it. (to the best of my knowledge, other Volvo compressors have different-looking clutches. As I may be wrong, please be sure of what kind of system you are working with, and gather information appropriate for that system.)

Please bear in mind that the instructions that I compile are just what worked for me, and I don't guarantee that they will work for you, or that you should follow them. Also, clutches vary, and so do specifications, fastener sizes, and procedures, I cannot cover all clutches, but I can cover what I've done. Please take the time to gather as much information on your climate control system as possible- fastener sizes, torque specifications, part numbers, you name it. All of this information can come in handy when you least expect it- be prepared for anything. Don't work alone- things can go wrong, and it's always good to have an extra set of hands. And, as always, when performing such involved work, use common sense and remember that PATIENCE IS EVERYTHING.

After every step, take an inventory of what you are left with, and make sure that everything makes it back to it's own place-


What to remember-
Make sure that the center clutch bolt is accounted for and kept in a safe place. It may be re-used if your replacement clutch didn't come with one.

Pictures associated with this step: Figure 1

1. The first step is to thread two screws into two of the points labeled "1B" in.(any two points, they will be used for leverage)In my case, these openings were M5-0.8. Now you want to get something long and thin, (a sturdy flathead screwdriver or so) and cross between the two screws. This will hold the compressor shaft steady while you remove bolt "1A", (it was a 10 mm, M6-1.0 in my case, not sure if they vary any between clutches.) With bolt "1A" removed, it is now time to slide the clutch off of the compressor shaft. Some online writeups say that you can use two screwdrivers, but the cramped bay of a B6304S is no place for unruly screwdrivers and such. RENT A PULLER. My local O'Reilly Auto Parts had a great puller set for rent(Part number 67100, if I remember correctly). The puller has a plate with four openings, one in the center for a bolt that pushes down on the compressor shaft (where "1A" was, and three openings to thread screws into the three points labeled "1B". As it pushes down on the shaft, it pulls the clutch off. The clearance to the fan shroud is tight, so be very careful. Take this step slowly, there's no rush, and the gentler this job is done, the better for you and the compressor.


What to remember-
Make sure that the pulley snapring is accounted for and kept in a safe place. It may be re-used if your replacement clutch didn't come with one.

2. Now you are looking at the pulley. The pulley is pressed onto the compressor, and is secured by a large snapring. It helped me to get under the car with a mirror, but the snapring was out in seconds with a good set of 90 degree snapring pliers. Snaprings can go flying, so make sure to be very careful and not lose the snapring or, worse, hurt yourself or others. With the snapring off, the pulley can be removed with a pulley puller. As before, you will be using the compressors shaft with the puller: as the bolt drives down on the compressor shaft, the jaws slide the pulley off. Be very very careful to use even pressure when pulling the pulley so as not to distort any surfaces, and go slow- better to take your time doing the job now than take the time doing it all over again.


What to remember-
Make sure that the three coil screws, and the wiring harness bolt are accounted for and kept in a safe place. They may be re-used if your new clutch didn't come with them.

Pictures associated with this step: Figure 3, Figure 4

3. Now that the pulley is off, the coil is exposed. The coil is held in by 3 philips head screws. At this point you want to remove the bolt securing the wiring harness to the compressor, this is shown in figure 3A. Figure 3B shows a grommet in the compressor body through which the 12v hot wire feeds to the coil. Push this grommet through from the back, and it should come right out of the front. You can now remove the three screws securing the coil (figure 4). You may need a stubby screwdriver to clear the radiator fan shroud. Again, a mirror under the car can make this job easier. With the three screws removed, the coil should come right off of the compressor. Remove it with care so as not to damage the coil wire. Before installing the new coil, or reinstalling the old one, make sure that the points where the coil is screwed into the compressor are clean and conductive, as this is where the coil grounds.


What to remember- Be patient, don't force anything.

5. To install the new clutch, follow the guide backwards. Use a press to press the pulley back onto the shaft, and carefully seat the snapring into it's groove. Remember that snaprings can be unruly, so use caution in this step, and be sure that it seats completely into it's groove before proceding. Use the shims in the clutch or in the new clutch kit to adjust the air gap between the clutch and pulley. Press the clutch onto it's shaft, as always, slowly, and evenly so as not to distort any surfaces. Exact air gap specs were unavailable to me, so I had to guess and check. Also, on my zexel compressor, there was a lip on the pulley that rendered checking the airgap impossible. Use good judgement and remember that worn or resurfaced clutches will need fewer shims to meet their clearance specification. If your clutch cycles in and out after assembly, and tapping the clutch causes it to engage, if even momentarily, it is possible that your airgap is off and the clutch needs to be reshimmed. Check the obvious first- refrigerant levels can cause clutches to cycle, too, and that's a much easier fix than reshimming a clutch.

Tighten the bolt on the clutch, (Please take the time to find the actual specifications for your compressor, it will save you a lot of trouble.)

A good friend can help make this job a lot easier, especially if they are mechanically inclined, and even more so if they are more mechanically inclined than you (IMG:style_emoticons/default/smile.gif) A big shout out to the good buddy that helped me get this job done.

This was how I carried out my clutch replacement- hope it is of use to anyone else out there, and hope it leaves you with many more years of happy, comfortable motoring!


-Dan964

If you like the writeup, feel free to post it on your website, but please leave my "-Dan964" at the end (IMG:style_emoticons/default/liebe011.gif) Will post pictures ASAP, and step 5 needs to be renumbered step 4. It's up to you whether or not to add the following to the writeup, but I think it would be useful:


P.S. I'd also like to add that locally, I could not find a decent pulley puller for the AC pulley that would clear the fan shroud, and while I would NOT suggest this, I removed the pulley by rocking it back and forth off of the compressor with two screwdrivers. If you HAVE to do this, take it slowly, use even force, and remove the pulley from two oposing ends so as not to bend anything. Try your best to secure a true pulley puller, and use that. Improvisation is important in mechanic work, but you have to be careful and be sure that you are doing it in the safest possible way for you and for the equipment.

awesome writeup dude! A very detailed guide to doing that sort of work, i think that will prove handy to lots of people!

Does your ac work now?

Matt

Thanks bro, It does work now, but it's cycling (low freon)

adding refrigerant and returning my core this evening.

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