Well, I wouldn't say in this case the compressor caused the PS to go out. I am not sure how many miles you have on the vehicle. Over 100K. That is a lot of miles for bearings and pulleys to be spinning. How many miles do you have?
Your model requires the PS pump and hoses to be inspected every 6000 miles. Now does that mean it is going to fail at 6000. No. But again, if you think of how much that little wheel has been spinning. Wow.
Of course it is possible the strain of the compressor puts a strain on the PS since every time you turn the wheel the PS needs the movement of the PS pulley.
Kind of like shocks. If you don't replace the shocks the car bounces more and that puts a strain on the springs and ball joints etc. Before long your suspension is shot because of a shock.
I feel it was normal for your PS to go out. So I wouldn't concern myself there.
As for the compressor and not using it. The compressor will spin no matter what. Even if the compressor wasn't working it would still spin. Many drive for years with no AC (compressor bad) but the pulley part is just fine.
As for the clutch however, yours would engage and not engage depending on the need for cooling. The cycling you are hearing/feeling is normal. It would have to be checked by gauges of course. Though if it does get low it my cycle more or if a pressure switch goes bad. But if I understand you correctly I think in this case the pulley is just tired and worn and went.
Last, if you notice on engine cleaners they state do not spray on pulleys etc. Because they remove any lubricant. Now many bearings are sealed but. It only takes a small defect and now the bearing starts to deteriorate.
I just replaced the idler pulley wheel on a 1999 Mercedes ML320. Totally disintegrated the pulley and all. The only thing left was the inner part of the bearing and the bolt holding it on.
Again, I think it was just time.
Sunday, August 9th, 2009 AT 10:50 AM