Rear Brake Rotor Stuck

[nm735]

While waiting for the machine shop to finish with my block and head, I decided to do the shocks and springs on my 735i. I then decided that I might as well do the trailing arm bushings as well. After all, they're right next to it, right?

Somehow, the job has been going smoothly, except that my right rear brake rotor is stuck. I imagine the left is also stuck. This means two things: This has turned into a brake job as well, and something is going on with the parking brake. I'm guessing that the parking brake has worn into a groove and now the rotor is stuck. I have tried to use a screw driver to release the sprocket thing, but I have failed miserably at it. I have said several horrible things to my car, and I'm getting ready to take my 30-30 to it.

Does anybody know how I can get the rotor off?

[nm735]

Nevermind. In my rage, I decided to burn the rotor. Metal is not flammable. Upon realizing this, I went after it with a rubber mallet, the closest weapon available. Rotor broke loose. Turns out burning things and hitting them are the answer to all my problems.

[youngbimmer]

Nevermind. In my rage, I decided to burn the rotor. Metal is not flammable. Upon realizing this, I went after it with a rubber mallet, the closest weapon available. Rotor broke loose. Turns out burning things and hitting them are the answer to all my problems.

I’ve used a big block of wood to smack the rotor from behind, as well as a rubber mallet with success. Glad you got it off! It’s always frustrating when you’re working and get stuck trying to take something off

[nm735]

New problem: I have no idea how to disconnect the parking brake cable. It is just stuck in the actuator, and then I don't know how to disconnect the sheath from the hub. Anybody else do this before?

[shogun]

this will help a bit
https://www.bimmerforums.com/forum/s...-cable-removal
https://www.bimmerforums.com/forum/s...Brake-Overhaul
https://www.youtube.com/watch?v=swPSijXQLKc
http://bmwe32.masscom.net/sean750/ad...rkingBrake.htm
checked the Bentley manual?

[nm735]

I did check the Bentley. It just says "disconnect the cable." I was able to discern the little pin holding the cable in after about an hour of looking at the thing. Tapped it out after about 15 minutes of swearing.

All of this looks helpful. I have sprayed the cable sheath with PB blaster, and I will do my best to yank it tomorrow. It seems to me as though there is no trick to it. Just oink on it until it comes out. Which is gonna feel great.

[shogun]

2nd one will go faster, even the workshop manual does not help, one sentence only: unscrew parking brake cable on trailing arm and pull out

[nm735]

Fire is the solution to everything. I have gotten the damned trailing arm off the car. It took all day. Everything you sent me was technically completely accurate, but was not enough to prepare me for what I had to do.

I unhooked the parking brake cable from the handle, and pulled it out. I have no idea how I'm going to undo that, as it won't pull out, but that's future-me's problem. I used a punch to tap out the housing. The punch got stuck next to the cable. I heated up the end of the housing with a torch and it released. The last thing holding in the trailing arm was the ABS sensor. The Bentley manual said "remove ABS Sensor." It took hours. Alternating between a rubber mallet, a slide hammer, a torch, and PB blaster, I was able to eventually free the ABS sensor. The trailing arm is now free. Now all I have to do is press out the old bushings and press in the new bushings. Then I reassemble. Then I do it again on the other side. Then, I have to do the front springs. I'm going to die.

I hate this car. But it can't win.

[shogun]

soon you will have done the repair. Here one more link https://www.newtis.info/tisv2/a/en/ maybe there is something inside more in detail, you have to register and log in.

[nm735]

Update:

The other side is going faster. Some of it is that the driver's side is cleaner. Most of it is that I now know how to do these things better. I have dislodged the cable from the driver's trailing arm, and am working on freeing the ABS sensor prior to removing the drive axle and strut. My next question, and I regret asking this, is how much more work is it to remove the rear differential from here? Should I even bother doing it?

[shogun]

I only removed some final drives from parts cars but never installed one, I used the Bentley which you also have. Any special reason you want to remove it? Seal replacement is possible w/o removing the diff, see here under driveline http://bmwe32.masscom.net/
http://www.bmwe34.net/E34main/Mainte...tial_seals.htm

[nm735]

The single biggest reason is I don't think it's acting as a limited slip differential anymore, but my Father has given contradictory statements about whether he has seen both wheels turning in the snow. When I changed the diff fluid, it was disgusting and I am worried that the diff has been damaged.

Also, I figured it might make sense to replace the mount and any bushings under there. It doesn't take much to get back under the car. But I also am having a hell of a time with simple things like the brake sensor, so I'm wondering how difficult it actually is compared to the manual.

[shogun]

this will help http://www.bmwe34.net/E34main/Mainte...fferential.htm
If you would like to know what kind of diff is installed in your car, refer to the data tag located on the rear driver's side of the diff. For example "S3.15" means a LSD 3.15 diff while a "2.93" means an open end 2.93 diff.

[nm735]

You're a godsend. Looking at that article, I have decided it is not worth the trouble to pull it. It still works fine for my purposes, and the engine isn't putting enough power down to make an open diff a nightmare. I'll have it yanked when I have the transmission yanked.

That said, I believe the diff to be original to the car, which means it is the 25% slip diff listed on the build sheet. I cannot verify this, however. Years of neglect have left the tag illegible. It's possible it has been swapped out. The transmission is not original to the car, and neither was the ECU I found when I decided to replace the ECU. By my count, there are at least 7 other cars with parts in mine. So it wouldn't surprise me so much if the diff were a replacement. It would surprise me that somebody bothered to do it, but then again this thing was valuable once.

[nm735]

Update:

After several months of trying to find a shop that could pull the trailing arm bushings, I have managed to get the bushings on my trailing arms replaced. Driver's side trailing arm is back on and torqued up. Brake line hooked back into the car, and the parking brake reassembled.

This was a mistake.

[youngbimmer]

The trailing arm bushings were that big of a PITA? I plan on coming mine soon ad they look to be in terrible shape and leaking orange goo

[nm735]

I started this back in December. Basically, I had to bring the arms to two different shops, only to find that neither could press the bushings out. I then had to drive to the BMW dealer in Santa Fe for them to attempt it. Worst part is that the passenger's arm is bent, and the replacement I bought has a twisted up dust cover, so I have to disassemble both the bent one and the replacement in order to make ONE acceptable trailing arm.

If you can avoid doing the trailing arm bushings, do it. Pay somebody to do it if you can afford it.

[nm735]

Today I put the rear strut tower back together. It's bolted in, but not torqued. The old shock could be compressed by hand with almost no effort, and it would rebound slower than the car accelerates. I assume the spring is bad, as the rear was sagging pretty badly. Which is why I started this assault on my sanity, wallet and physical well-being in the first place.

Next step is to torque the strut into place, then adjust the parking brake. Which brings this full thread full circle. I must be making progress. I've been this place before, but with less rust.strut.jpg

[nm735]

Car is on the ground. Not done yet, still need to address the brakes, but I have to wait until I get a new soft line. Will start new thread with update and any useful instructions.