This message is marked as Important.

Subject: How to change the rear brakes and rotors on your E23 7-series Author: DavidC (moderator) : member since December, 2003 : 11909 posts Posted on: 2005-03-10 22:34:26

See also: Changing the front pads and rotors on a 1986 735i

In this article, I’ll take you, step by step, through the process of installing new brake pads and rotors on the rear wheels of my 1986 BMW 735i. The 735i has disc brakes all around, so the same procedure applies to nearly any car with a similar disc brake setup, including the e24 6-series and e28 5-series vehicles.

You’ll learn to identify the major components of the rear braking system and how to disassemble and reassemble the calipers, caliper guide, rotor, pads and electrical connections. Most repair shops routinely charge hundreds of dollars, plus parts, to change rear brakes so its worth it to learn how to do it yourself. It’s a lot easier than you may have thought, too.

Before we get started, remember to pay attention to safety. Never put yourself or others into a dangerous situation by improperly jacking up the car or by mishandling tools. You may find it comforting to know that its not necessary to get under the car to do this job.

What you'll need:
New brake pads (two per wheel, purchased as a set)
New rotors (one per wheel)
New brake pad wear sensor
Two new 5mm rotor set screws
17mm socket
19mm socket
5mm hex bit
Torque wrench
Ratcheting socket wrench or, preferably, an air wrench
Brake cleaner spray (the non-chlorinated type is preferable)
CRC Disc Brake Quiet or similar compound
Anti-seize lubricant
Paper towels
Latex gloves
GoJo or other degreasing hand cleaner for cleanup


The new rotor and pads. This happens to be the front pads and rotor, but the rear is nearly identical (the rear pads are a little smaller -- see additional photos below). Note that this is for one wheel. You'll need another set just like this for the other wheel, too. Rotors and pads should always be changed in wheel pairs. I elected to go with OEM rotors but using Mintex pads, which are reputed to be as good or better than OEM but with lower dust. They were purchased from BMA Auto Parts. The cost was $38 each for the rotors and $29 for the set of pads, plus shipping.


A tube of anti-seize lubricant like this will make your life easier the next time you change the rotors. We'll apply it to the moving pins of the calipers and, more importantly, to the inside surface of the rotor where it meets the mounting plate for the lug bolts. This will prevent rust from forming which can seize the two parts together.


Chock the front wheels, jack up the car and remove the rear wheel. The lug bolts are 17mm. Don't forget to use jack stands for safety.


A close-up view of the caliper assembly for the right rear wheel. The little black wire is the brake pad wear sensor. The left side won't have a wear sensor. Remove the anti rattle clip from the caliper assembly (it's already removed in this photo).



Here are the new brake pads.


Remove the two rubber plugs covering the caliper pins from the back side of the assembly.




Using your hex bit, remove the two caliper pins.


This is a view from the inside of the right rear wheel. Slide the caliper assembly off of the rotor and place it on a box to support it and avoid stressing the rubber hydraulic line. Remove the two 19mm caliper guide bolts.


Slide the caliper guide off the rotor.


Using a 5mm hex bit, remove the rotor set screw. The screw is made of relatively soft metal so be careful not to strip it. Make sure that the parking brake is released, otherwise you won't be able to get the rotor off. Next, remove the rotor from the wheel. If the rotor is rusted tight and won't move, check out my front brake and rotor replacement write-up, which shows how I removed a stuck rotor using an 8" gear puller.


Disconnect the electrical connection for the brake pad wear sensor. Note that the sensor is present only on the right side of the car. Remove the old pads from the caliper assembly.


The old pad and wear sensor.


Insert the new wear sensor into the new pad.


Using a C-clamp, compress the caliper piston so that it’s flat against the inner surface of the caliper assembly. Do this slowly. You may need to drain a bit of fluid from the brake fluid reservoir.



Apply anti-squeal compound to the back metal sides of the new pads. Take care not to get any on the friction surfaces on the other side. I used CRC Disc Brake Quiet, readily available at Advance Auto Parts and similar places. The first photo shows the front pads with the CRC Disc Brake Quiet container. The second photo shows the rear pads.


Install the new pads into the caliper assembly.


Apply some anti-sieze compound to the face of the wheel hub then install the new rotor. Secure it with a new 5mm rotor set screw. Torque to 14 foot pounds.


Reinstall the caliper guide and the two 19mm caliper guide bolts. Torque them to 81 foot pounds. Now install the caliper assembly onto the rotor and caliper guide.


Reinstall the caliper pins and torque to 49 foot pounds, followed by reinstalling the two rubber caps. I applied a bit of anti-seize lubricant to the shafts of the pins (but not the threads) before inserting them.


Reconnect the electrical plug for the brake pad wear sensor.



Don't forget to reinstall the anti-rattle clip. I neglected to take a photo of the right wheel, so here's a shot of the corresponding left wheel.


If you really want to get fancy, paint your calipers and rotors to keep them looking new.

Reinstall the wheel and torque the lug nuts to 81 foot pounds. You're done!

David Cecil, KI4GZR
'97 740iL, 129k miles
'92 750iL, 78k miles
'86 735i, 97k miles

www.e38.org has links for everything about your BMW 7-series automobile

• How to change the rear brakes and rotors on your E23 7-series (pic) (url) - DavidC 2005-03-10 22:34:26 (5124 views)
  • What brand pads/rotors do you use? (nt) - luquette 2005-03-14 10:52:50 (527 views)
    • Re: What brand pads/rotors do you use? - kff 2005-03-14 11:14:33 (550 views)
  • Dont forget.... - James '84 745i 2005-03-11 07:03:18 (692 views)
  • Re: How to change the rear brakes and rotors on your E23 7-series - LoneRider 2005-03-10 23:12:57 (631 views)
    • Thanks. It's my wife's Sony DSC-W1. Though all these shots are - DavidC 2005-03-10 23:55:08 (539 views)