09-14-2010, 12:10 PM
Ultimate Driving Machine
Location: So. Calif.
Join Date: Jan 2002
Mein Auto: '13 F10 550i; '13 R1200GS
I wrote up a DIY for how to do this and annotated a few pictures. I hope this is helpful for anyone else that is interested:
What you need:
Part Number: BMW Pedal Assembly BM35-00-6-751-975
Area light to illuminate footwell
Torx driver and bits
Flat blade screwdriver
3/8" Socket wrench with metric sockets
6" socket wrench extension
Disclaimer. Ok, brakes are a pretty important component of a car. If you are not comfortable working on your brakes, you should probably hire a professional mechanic and if you have not performed mechanical projects yourself previously, this would probably not be a good place to start. Take your time and work slowly. I am not a professional and have no way of knowing if these steps are correct or complete or dangerous, etc. This is my best recollection of my installation and it worked for me. Your mileage may vary.
Disconnect battery before working on the car is typical advice. However, I did not do so and didn't have any issues as a result. Again, YMMV.
Remove the lower dash panel on driver's side. This black plastic panel is held in place primarily by 3 torx screws that are located in the picture below as well as a variety of tabs.
Remove these torx screws and gently pull down on the panel and then towards you and it should release. If not, read below on installation instruction of the panel to more fully understand the various tabs that hold it in place.
The panel should now be free and hanging by 4 wiring harnesses which will need to be removed from the panel so the panel can be removed from the car to provide enough space to remove and replace the pedal assembly. Starting at the right side and looking at the inside of the panel as in the Picture below (insert panel pic), remove plug from speaker (hold base and pull firmly, no need to press anything to release), same for footwell light to the left of the speaker.
Next item is the MOST BUS connector which is a fiber optic connector attached to a 4" long plastic piece which can be accessed from the front of the panel and which is used by BMW technicians to pull the connector through this panel and attach a computer to the car without removing the panel. You will see where the BUS connector connects to this 4" plastic piece. Press on the side of the connector and the wiring will detach from the 4" plastic piece. As far as I can tell this is simply a place holder for the BUS connector so the technician can easily grab it. Note the cool red light given off by the fiber optics.
The last harness to disconnect is some form of sensor as best I can tell on the far left side of the panel which is about the size of a deck of playing cards. It has a connector I have not seen previously and didn't want to mess with trying to see if it unplugged or not, so I removed the whole sensor with wire attached from the panel. This device is held on by 2 plastic clamps, one on front and one on back of the sensor, spread those apart with one hand while gently prying under the sensor with a plastic trim tool or screwdriver and you'll see that it begins to slide up on the two vertical plastic pieces...it pulls off easily with virtually no pressure. Ok, so now you should have the lower dash panel free from the wiring looms...remove it from the car to get it out of the way.
Next step: remove the brake pedal assembly. With 3/8" socket wrench with 6" extension, remove the 2 nuts on the firewall that hold the pedal assembly in place using a 14mm? socket. Then looking from the floor of the car and up to the front edge of the assembly you'll see a 10mm nut in a slot of the assembly. Do not remove this nut, simply loosen it so that you can slide the assembly out of its groove. Once out of its groove you will need to remove the brake light sensor before you can remove the pedal assembly from the car. The brake light sensor will be located in the brake light sensor mount as show in the picture above. Gently hold the sensor and pull it away from the pedal assembly...it is held in place by friction. One last connection...the brake booster itself...you will see the brass pieces wrapped around the pedal arm..picture doesn't show this but points to general area. On the left side there is a nut type locking device, I think called a speed nut or sheet metal nut which serves as a lock washer and nut ...you've seen them before and it can be removed by slightly releasing tension with a screwdriver and sliding it off the pinion and then from the right side of the brake arm pull out the pinion which holds the brake arm to the booster. Save both of these as you will need to re-use. Now the pedal assembly is free and you can remove it, although it will take a minute or so of manipulation so that you can do so.
Once removed, you will need to remove the brake light sensor mount from the old assembly and install on the new one. This is the black plastic piece labelled in the picture above. Simply pull it straight out and push it back into the new assembly.
Install the new pedal assembly is pretty much the reverse of the above. After all three nuts are tightened and pinion and speed nut has been replaced, reinstall the brake light sensor. Press it in and push all the way so that it makes contact with the black metal tab on the pedal arm.
Replace 4 wiring looms and sensor that were removed from the lower panel.
Before replacing lower panel, turn on ignition and verify that brake lights work properly and that car will NOT start without depressing the brake pedal. Brake lights should illuminate as soon as pedal is depressed. If brake lights remain illuminated without pressing the brake pedal and car will start without pressing the brake pedal, then you have not pushed the brake light sensor far enough into its receptacle. The sensor is not a mechanical plunger like the old days, but seems to rather be a magnetic switch, but I'm not sure. Double check that all three nuts holding the pedal assembly are snug and that the pinion and its speed nut are properly installed.
Now replace lower panel. There are a few things to pay attention to. First there is a female receptacle on right rear side of the panel and a corresponding male piece attached to the firewall…locate these before replacing panel so that you can understand how the panel goes back in. On the left side of the panel at the rear is a male piece that gets inserted into a slot that is atop the dead pedal. On the front right side of the panel along the transmission tunnel is a black tab which needs to go under the trim on the transmission tunnel…you DO NOT bend this tab it slides up underneath the transmission tunnel trim. It may take a little bit of trial and error..once you get the panel in place and before installing torx screws, gently tug down on it from near the back...if it pulls down you'll know you missed the proper insertion of the male and female pieces...if done' properly the panel should not pull down at all. You certainly don't want this thing falling down on your feet while driving, so be sure that you have it installed correctly. Once you have these tabs all in place you can then replace the three torx screws.