How do I replace AC idler pulley?

[Russell]

Going to replace my ac idler pulley tomorrow on my 95 525i. I just realized my Bentley is not clear on how? Could not find much in the archives. It looks as if the belt is held on by a tensioner and the idler pully is held on by a bolt.

Do I remove the tensioner (how?), then the belt, then the pulley? If so, what is the procedure to reattach the tensioner?

Thanks in advance

[Paul in NZ]

bump

[Rory]

Going to replace my ac idler pulley tomorrow on my 95 525i. I just realized my Bentley is not clear on how? Could not find much in the archives. It looks as if the belt is held on by a tensioner and the idler pully is held on by a bolt.

Do I remove the tensioner (how?), then the belt, then the pulley? If so, what is the procedure to reattach the tensioner?

Thanks in advance
Hi Russell,

It is very self explanatory once you get in there. Just remove the belt, pop the plastic cover off the spanner and push clockwise to release tension. Next crawl under the car. I seem to remember 3 or 4 bolts on the tensioner. It will be blatantly obvious, just remove the bolts. To remove the spanner, just pull the plastic cover off and undo the bolt (opposite way of releasing tension) :) Installation is reverse of removal.

Good Luck,
Rory

[Russell]

Still not sure how to get the tension off the belt? I believe the AC idler pulley is just held on by a single bolt which is under a cover. Are you saying that undoing the bolt will eliminate the belt's tension?

As with these cars, the first time for any task is the most difficult. Not like a mid 60s' chevy. :) Thanks again.


Hi Russell,

It is very self explanatory once you get in there. Just remove the belt, pop the plastic cover off the spanner and push clockwise to release tension. Next crawl under the car. I seem to remember 3 or 4 bolts on the tensioner. It will be blatantly obvious, just remove the bolts. To remove the spanner, just pull the plastic cover off and undo the bolt (opposite way of releasing tension) :) Installation is reverse of removal.

Good Luck,
Rory

[Russell]

I must have some sort of mental block and just not getting it :)

[Rory]

I must have some sort of mental block and just not getting it :)
Hey Russell,

Locate the spanner on the tensioner. It is a round black plastic thingy and the belt runs over it (in technical terms) ;) . Take a small flat bladed screw driver and pop the cover out of the middle of the spanner. You will expose a hex bolt most likely in the middle of the spanner. Take a 7 mm (I think, been a while) hex key or preferably a hex bit for your socket wrench and put it in there. Push the tool clockwise and you will see the spanner move and the tension will loosen. You can push it an inch or two total with 1/2 grunt of force and with your other hand slide the belt off. To remove the spanner for disassembly, simply use the hex bit in the same location but go counter clockwise to loosen the bolt. Let me know if you need anything else.

Good Luck,
Rory

[Russell]

Thanks -Now I know. Your term "spanner" confused me. I think of spanner as an open ended wrench. You have been most patient and helpful.

[Rocky A.]

are routed before you take anything off. My M50 has two belts and I used different ink colors for each one. Be sure to draw how each belt drives each component (ac compressor, water pump, power steering, various idlers, etc.). Without such a drawing, it will be quite a challenge to get all these belts back on correctly, at least it wasn't intuitively obvious to me...

[Russell]

THanks - this is the first thing I plan to do.

[Rory]

THanks - this is the first thing I plan to do.
A lazy man once said "Work Smarter, not harder" :D

From: http://www.logun.org/waterpmp.htm (S50, M50, it's all the same)

http://www.logun.org/change%20your%20water%20pump%20E36_files/pulleys.jpe

Best,
Rory

[Russell]

Great diagram- I am impressed!