DIY: Brake Pad Replacement DIY

SkyNet wrote

I've spoken to a few mechanics who say you have to replace the rotors every time you replace pads. Is this accurate?

Not necessarily. If they are well above minimum thickness they will just do pads. If you track the car as I did I ran lots of sets of pads before rotor change.

I changed my front pads today for the first time using this thread's treasure of usable information! I also used the opportunity to collect some essential gear for simple maintenance tasks, which might be of use to some others so here are my notes.

0. I never took the wheels off before, so I quickly realized that the shop does not torque them to 88 ft/lb but rather to twice that with an impact gun... So in addition to a 1/2-inch torque wrench it is also necessary to get a sizable breaker bar and an extra long impact 17mm socket. The extra long makes its possible to clear the wheel's rim with the wrench and the impact socket is safer than a normal socket (I sheared a cheaper simpler socket on my first try.)

1. I encountered a problem with my small metal jack head sitting uncomfortably against the hard plastic rectangular jacking brackets. After ordering a special adapter piece over ebay that did not arrive in time, I followed someone's advice and bought a $2 hockey puck as a sensible adapter. Worked safely and easily.

2. I did not open the brake fluid reservoir as I did not think the pressure makes any difference, and if there is a risk of overflow I'd rather have the lid on.
That worked fine.

3. All the actual work went exactly as expected from the detailed descriptions. The hardest bit is that you work blind, with your hands and sockets behind the wheel assembly. The upper retaining bolt requires an extension piece for your ratchet to get past the brake line. The retaining bolts only came out when I expanded the brake, before that I could unscrew them but they were still in the hole. Also, my brake pads were pretty far down to 4 mm or so, which made the expansion step with a screw drive a little harder, but it all worked. I also noticed that my brake seat and everything looked very dirty, but I had not special cleaner at hand so left it like that.

4. I was glad that I expected the glued-in outer OEM brake pad, which takes a firm attitude to pry out! Otherwise I would have been very worried at this stage.

5. The hardest bit was the putting the anti-rattle club back in. It took a lot of finger force to get the metal bits jointly into position and then pushing the centre bit in. Some swearing at that stage.

Overall, the first side took 90 minutes and the second side 40 minutes..

Safe travels!

I did my first pad change a week ago as well thanks to this thread. I found the first rotor the worst, especially getting the clip back in. It was a lot easier getting the clips in on worn pads (my street ones). I also found it unnecessary to use any more than my hands to compress the caliper (just slowly work it from the top and bottom), and that way you won't chip any paint prying with screwdrivers...

Final note, and this might have been mentioned before, but if you still have the pad sensors connected, make sure you zip tie them as far back from the wheel as possible. The first change I did I apparently left the sensor to lose, and it rubbed against the wheel... almost right through the wire. Cheap part to replace though.

My car just hit 62,000KM and the pads started squeaking. I bought a set of Stoptech Street Performance pads as a replacement. I was told that if these were installed carefully, I would not have to change the sensors. I guess something went wrong and now my iDrive shows me that the front and rear pads need to be replaced (this warning was never displayed before), the handbrake light is constantly on although the handbrake is fully pulled down, and the red light with the car on the hoist is on. I am hoping this all has to do with the brake pad sensors and it will disappear once I replace them. Just not sure why the handbrake light is on ....

Hey guys, I just used this guide to replace the front brakes on my 2012 e92 M3 and it worked great, however I came across an issue about 3 or 4 weeks later:

I was driving down the highway and all of a sudden, my car went into limp mode. I took it to the shop, they read the codes and found out that my vacuum line with sensor from vacuum pump to brake booster was damaged.

A costly $600 replacement...

In doing more research into the cause, I found out that some brake fluid spilled into a vent and saturated a sensor connector causing the weather packing to swell.

http://www.m3post.com/forums/showthread.php?t=861923

So please be careful when compressing the piston in your brakes, make sure the excess does not drip on any sensors!

JBimmer-3 wrote

Fourth- Sensor install: Keep in mind that the sensor connection is underneath the under-lining of the wheel well. There are 6 bolts to take off in order to have enough room to disconnect old one and connect the new one. You must install this or your warning lights will continue to trip.



this. i thought it would be a good idea to replace my rear brakes with a spare hour i had. was jamming along until i got to the brake sensor replacement. they really hid the sensor in a PITA spot on the E90. on our E53 it's super easy access. i ended up saving the sensor as a job for another day.

another tip for anyone doing the rears that i learned the hard way long ago. be sure your parking brake is disengaged.

I need to replace my rear rotors too, which I believe means I'll need to unbolt and remove the caliper carrier bracket too. Does anyone have the torque specs for the caliper carrier bracket? Thanks!

414bhp wrote

I need to replace my rear rotors too, which I believe means I'll need to unbolt and remove the caliper carrier bracket too. Does anyone have the torque specs for the caliper carrier bracket? Thanks!

Okay, to answer my own question...search!

http://www.m3post.com/forums/showthread.php?t=779243&highlight=rotor&page=2

Looks like the caliper carrier can stay attached and there is still room to change the rotors.

Great guide and good heads-up on the BMW-glued inner front pad. What a pain.
Anyway, that worked well. Went to bed the pads the other day (Hawk DTC-70) and came up with a ton of brake dust. Cool. Anyway I had little time afterwards and left the brake dust on so now the metallic components of the brake dust oxidized onto my wheels and somewhat ruined the clear coat on them. So don't make that mistake. Clean wheels quickly!
Haven't seen that tip anywhere else, so I figured I'd post it here. Most people with garage-queen cars won't have that problem too much but this is my daily driver and it ends up in the humid/wet conditions occasionally.

Big thanks to all for the excellent advice. I've done this swap a few times now both front and rear in prep for track days. The rear is easier than the front but once you get the hand of it neither end is that tough. I hand tighten the bolts that hold the caliper housing - easier to get a feel for whether they are lined up. Then I use a wrench and torque to spec. The springs can be done easily by hand. I had to study them a bit to figure out how they come out and go in, but once understood they can be done by hand relatively easily. The screw driver trick on the front to push the piston back is awesome. However, would not work for me when there was a big discrepancy between the pads; that is, going from very low worn pads to fresh thick pads. In this case I had to resort to the C-clamp. Don't forget to loosen the lugs prior to lifting each respective wheel. Don't forget to open the brake fluid reservoir. Caliper hangers are cheap and worth having to keep tension off the brake fluid line. The only pad without a sensor is the driver rear. Mini ramps easily available and cheap on Amazon work great for accessing the front center jack point for lowering onto stands. Again, thanks for all the insight all.

So I replaced the rear brake pads, along with the brake wear sensor, did the reset procedure, and I still have the warning coming up. I reset both front and rear sensors.

How many sensors are on the front? Do I need to do something to them also?

PeteV wrote

So I replaced the rear brake pads, along with the brake wear sensor, did the reset procedure, and I still have the warning coming up. I reset both front and rear sensors.

How many sensors are on the front? Do I need to do something to them also?

There's 2 sensors on the front (1x each wheel) and 1 sensor on the rear. You might need to just make sure they're pushed in all the way. It's a pretty tight fit.

Hello all. I replaced my rear pads and sensor but I can't get the car to rest. I go through the process with the trip and BC get to the rear brake icon and hit and hold reset. I get 5 dashes no miles showing. ??? Any ideas? Also shows I need front pads but they look good. Rear was just cutting into the sensor.

Thanks to lucid and others that added to this thread. Just replaced brakes all around yesterday and these tips make the job much easier.

I took a quick vid of me changing the rear pads just to show how easy it is. If my goofy ass can do it, anyone can. Vid would have been half the length of the retaining clips didn't give me any trouble. I haven't touched the oem brakes in over a year, so I sort of forgot how to pull the clip out.

roastbeef wrote

I took a quick vid of me changing the rear pads just to show how easy it is. If my goofy ass can do it, anyone can. Vid would have been half the length of the retaining clips didn't give me any trouble. I haven't touched the oem brakes in over a year, so I sort of forgot how to pull the clip out.

Good job man I'm not a handy man myself and I will change my pads and rotors soon. Quick question, did you open the brake reservoir lid to prevent overflowing or is it really necessary. I've just read horror stories about brake fluid overflow when you reset the piston back. Thanks.

lmendz71 wrote

roastbeef wrote

I took a quick vid of me changing the rear pads just to show how easy it is. If my goofy ass can do it, anyone can. Vid would have been half the length of the retaining clips didn't give me any trouble. I haven't touched the oem brakes in over a year, so I sort of forgot how to pull the clip out.

Good job man I'm not a handy man myself and I will change my pads and rotors soon. Quick question, did you open the brake reservoir lid to prevent overflowing or is it really necessary. I've just read horror stories about brake fluid overflow when you reset the piston back. Thanks.

No, I don't. I opened the cover to check it the first time and nothing happened, so I don't bother with it anymore.

roastbeef wrote

I took a quick vid of me changing the rear pads just to show how easy it is. If my goofy ass can do it, anyone can. Vid would have been half the length of the retaining clips didn't give me any trouble. I haven't touched the oem brakes in over a year, so I sort of forgot how to pull the clip out.

Pad spring clip 1 , roastbeef 0

Does anyone use an impact screw driver to remove the 2 bolts from the rotor? I'm just curious coz this video showed here. Thanks.

lmendz71 wrote

Does anyone use an impact screw driver to remove the 2 bolts from the rotor? I'm just curious coz this video showed here. Thanks.

I was wondering the same thing when I changed mine (due to watching that exact video), but decided to try it without at first and it ended up working. It's been quite a while since I did it, so the details are fuzzy, but iirc, I just used a regular allen wrench with the force of my hand. The bolts were not torqued down very tight.

if you're having a really hard time with it, put the allen wrench on it and link the closed end of an open/closed end wrench and use it as additional leverage.
where are you in socal? i have an impact and all the reducers/sockets to blast that thing off, but that would be at your own risk...

I am editing a series of videos of me installing a Stoptech BBK on all four corners.

This is the removal of the rear brakes. The next video will be rear BBK install followed by the front removal and installation.

I love the new brakes.