E9X M3 Front and Rear Brake Pad how-to. This is another simple maintenance job on the M3, with the trickiest part being the outer retainer clips. The other thing different about this car’s pads is that they come with clips that lock the pad into the caliper housing, either at the piston or the outer location. I believe these are for anti-rattle, but seems pointless here. I ordered titanium shims for track work, but those will go on special track pads that have flat backs. I also do not deal with brake pad wear sensors, so please take note.
- Jack & stands
- Likely will also need jack pucks for the BMW jacking points
- 7mm hex head
- Flat head or small pry bar
- Piston compressor/pad separator/c clamp
- Brake Grease (I used this)
- Copper antiseize (I used this)
- New pads (I ordered Ferodo DS2500s front: FCP1628H rear: FCP1672H)
- Zip ties
Car up on stands, rear off. Picture below is the driver’s side brake caliper & rotor:
The first step is pulling off the retaining clip. This was initially the most difficult part in this job. Push the clip rearwards from the center of the clip – once it’s off it’s a little easier to understand the shape, but essentially you are trying to get that middle tab off of it’s resting position.
There are two caps covering the slider pins in the rear. You can use your fingernails to remove these. You can also remove the brake pad wear sensor. Hopefully, if you were like me you are doing this before the sensors triggered anything – as I do not reconnect these. You can just find a simple spot to zip tie these out of the way, covering the end with electrical tape – they’ll never go off again, and it’s up to you to check your pads from time to time.
The slider pins have a 7mm hex at the end. Once these are worked off, the caliper is physically free, as those were the only things holding the caliper to the carrier. Note that for the fronts, the top slider pin is shorter than the bottom. You will have to use a flathead/pry bar to slightly compress the piston and pull the caliper towards you away from the car, position the flathead between the carrier and the compressor near where the brake pad arms are.
Pop out the pads and compare them with the new ones, making sure the size, shape, and connections are the same. You can balance the caliper on top of the rotor for now, or if it’s going to be a while/unmonitored, zip tie it to the suspension to suspend it.
If you are confused about which end goes where, the shorter end of the pad is what goes closer to the hub. The caliper also won’t go in all the way with the pad in incorrectly. I first used a brake pad separator to compress the caliper back. Either open the bleeder on the caliper or the brake master cylinder here, as fluid will come up or out when the piston goes back.
Clip in the new pads accordingly.
Once that is done, you can fit the caliper back onto the carrier. It should fit in smoothly, and if not, something is not aligned/installed correctly. I don’t have a picture, but clean the slider pins with light sanding, wipe down, and grease before reusing. Reinstall the pins, if you look through the top of the caliper you will be able to see where the pin enters the carrier. I’m not sure what the torque specs were, but I did these pretty tightly. Don’t forget to reinstall the caps.
Last bit is putting the clip on – align the arms where they need to be positioned and then push the center of the clip out and in so that the clip gets locked into its original position. It’s tough at first but pretty easy after you’ve done it a few times.
The rears are exactly the same process, but with a slightly different shaped retaining clip. To get this off I pulled the front off/away from the caliper, and then pushed forward – there are little hooks on the ends that go into the holes that you need to get off for the retaining clip to come off. I used flatheads in this picture but using fingers I think is easier.
Again, same deal here. Two slider pins in the back with 7mm hex head, pull off to clean and use a flat head to work the caliper off the carrier.
Compress the piston back, compare and clip in the new pads. I tend to use antiseize on contact points, but not that urgent in this application, I don’t think.
Once the caliper is realigned, clean, grease, and reinstall the slider pins & caps, again I did this fairly tightly but without a torque wrench. I usually aim to tighten similar to where it was when I uninstalled the part.
I found reinstalling the rear clip easier than the fronts. I simply aligned, as in the picture below, and pushed the center of the clip forward. It should clip in naturally from there.
That’s it! Don’t forget to check your brake fluid level (actually, this is a good time to also bleed the brakes) and pump the pedal several times before driving to get the pistons & pads back up against the rotor.