Hey everyone,
I chose to write this DIY because I had a hell of a time replacing this bracket with no other clear DIYs nor a Bentley manual that accurately depicts the compressors we have on our M42/M44s.
I broke the mount point on the bottom of the bracket for the A/C belt tensioner during a belt job in October. The mount is made of aluminum and is easy to break if the bolt holding the tensioner pulley is over-tightened.
The diagrams on RealOEM and in the Bentley do NOT accurately depict this repair. Once the initial mystique was removed from the job (thanks in part to members on this lovely forum), it was an easy repair.
Tools needed:- 6mm hex bit (a long one -- I used a ball-head long bit from Home Depot)
- 8mm hex bit
- 13mm socket
- Torque wrench
- Rachet strap
Materials needed:- New A/C compressor bracket (64-55-1-739-627)
- (Optional) 4x hex bolt (07-11-9-904-533)
- (Optional) 1x hex bolt (07-11-9-912-570)
- (Optional) 3x allen bolt (I don't know the part number)
Procedure: #1. Drive your beloved car onto ramps or jack up and place on jack stands. This job does not require that the wheels be removed, so whatever you prefer works. I will note that using ramps makes it slightly easier to "hold" the compressor up during bracket removal.
#2. If applicable, remove the A/C accessory belt. Turn the tensioner to the right to loosen it using an 8mm hex bit. Remove the hex bolt holding the tensioner pulley in place from the bracket. In my case, the entire tensioner was already broken, so I could skip this step.
#3. Remove the top allen bolt holding the compressor to the bracket using the long 6mm hex bit. I would recommend removing this bolt first to allow the weigh of the compressor to be distributed to the bottom bolts first. Trying to remove this top bolt when all the weight of the compressor is being supported by it is definitely not fun.
The bolt is located on the rear of the bracket, above the subframe and steering rack.
Step 1a1.jpg The bolt is invisible from below, so it helps to (1) use the long hex bit and (2) have a thin smartphone handy (like a newer generation iPhone) to take intermittent photos to "guide" the bit into the bolt head.
Step 1a.jpg Step 1b.jpg When the bolt is removed from the compressor, it will still not be free from the bracket due to the positioning of the refrigerant lines. It will sit in the threaded hole of the bracket, but the compressor will nonetheless be free.
Step 1b2.jpg Continued . . .