Replaced my rear brake pads - some DIY tips

[Emory]

Hi guys, I changed my rear brake pads and sensor yesterday. I apologize for my thread last week where I was complaining about being surprised about the rears wearing out well before the fronts. To make it up to you, I'll share some tips for the DIY-ers.

It was satisfying. The pads were $59 from Bimmerzone. The sensor was $16.95. The anti-squeal material was $2.99. I can only guess what the dealer would charge.

I did not take pictures, primarily because the E90 brakes haven't changed tremendously from the E36 or the E46, and there are existing websites that document how to change their pads. Here's a good site, documenting the rear brake pad change of the E46:
http://m3.madrussian.net/diy_rear_brake_pads.shtml

I did not change my rotors. (It's not a big additional step - it requires removing two caliper carrier bolts and one rotor retaining bolt.) On inspecting my rotors, there was very little wear.

Okay, here are my tips:

1. Jacking up the car. Okay, I'm not trying to belittle anyone here - it's just that there is an issue with raising the E90. On my prior BMW, an E36, there were holes on the lower panel where you inserted the jack to raise the car. Once raised, one could put jackstands under the jackpads (they were made of rubber and like hockey pads.) The E90 has those rectangular plastic jackblocks, which are $4.95 (I know because I had to replace two that were somehow missing.) The challenge was, how can you put the jackstands under the jackblocks? There's no consensus online on a central subframe point where you can jack the car without damage. I did what someone else suggested - I put my jack under the front jackblock, which lifted the rear jackblock enough to put a jackstand underneath. Oh, and I used a small block of wood on top of the jackstand, because those plastic jackblocks are not durable - I did crack one.

2. Brake fluid reservoir. It's hidden. There is a nearly-square cover on the drive's side next to the cabin filter cover, pretty close to the windshield. It comes off with two tabs. My experience is that when I've compressed ther piston on my brake, I've never had my brake reservoir oveflow, but I watch anyway, due to the risk of what brake fluid does to pain.

3. Removing the anti-rattle clip. On my E36, I took off the clip with a screwdriver, using the rotor hub as a fulcrum and pushing the body of the clip towards the rim. On the E90, however, there is more space between the clip and the rotor hub. Here's a picture from an E46 website:



I found it was much easier, and you are unlikely to scratch anything, if you use a v-jaw plier like the one I have:


and place one jaw of the pliers on the outer side of the caliper and the other jaw on the center of the anti-rattle clip, and just give a little squeeze. The clip comes out incredibly fast and easy. (BTW, putting the clip back is done by hand and it simply snaps right back in.)

4. Replacing the brake sensor. This is not difficult, but it's a little bit of a pain. It's on the right rear only (on the fronts, it's on the left). The sensor part is an L-shape that hooks into a gap between both pads. The wire portion runs along with the ABS sensor wire and is in three reclosable clips. The trouble is, the connector of the sensor runs towards the back of the car and is hidden behind a felt-like wheel well liner. You'll have to remove at least three 8 mm bolts and one 10 mm nut to get to the connector. Be prepared for a little shower of dirt and gravel as you remove the liner.

5. What makes your day, once everything is assembled: Putting key fob in slot, pushing start button (but not starting engine) ->holding odometer reset button to get to service lights->seeing red warning light for rear brake->pushing button at end of stalk to get the word "RESET"->pushing button again and seeing warning light disappear. Priceless.

I hope someone finds these helpful.

[RonNSoCal]

Great write up. Who makes the rotors for our cars? I know my Roadster had Zimmermans and Brembos were also a choice for either the fronts or rears, I cannot recall which one, but they did not seem to have rotors that would fit both axels. The reason I am curious is because when I changed rotors on the Roadster, I was able to find Zimmerman drilled rotors. I painted the rotor hubs and edges with high temp paint and they came out beautiful. I plan to do the same with my Coupe when the time comes. Also, did you use stock pads or did you switch to a dustless type pad to keep the wheels cleaner?

[Emory]

Thanks. Regarding who makes our original rotors - I'm not 100% sure. When I had my E36, I bought the Balo brand from Bimmerzone, as they were identified as an OEM supplier. This time, I got the Zimmerman coated Z, as Pelican Parts stated they were an OEM supplier to BMW. (What's confusing is that Pelican Parts also sells a "BMW" brand rotor, as well as Balo, which they also call an OEM.)

I bought stock pads this time. I hate the dark dust as much as anyone, but in my E36, I had installed a different pad - PBR Deluxe (I don't see them listed anymore) which was from Australia. They definitely had less dust, but I could also feel less of a "bite" - they certainly had less grab than the OEM pads. I'll take the stopping power of the originals over cleaner wheels.

The brake sensors are also improved. When I had my E36, I knew about the sensors, and that they were inexpensive and easy to replace. I just figured I'd wait till the warning came on and change the pads then. Well, I had taken my car to the shop for something else, and the mechanic commented, "You're down to 1% of your front pads." I changed them a week later, and sure enough, one pad was down to about the thickness of three sheets of paper (and the inner edge of the pad was down to metal.) That E36 brake sensor was still intact. The head of the E90 sensor is constructed differently and it worked faithfully.

[RonNSoCal]

On my new coupe (08 328i), the stock pads seem grabby too. I am not sure if this is due to the brake pads or the regenerative braking that helps recharge the battery. At any rate, whether the pads that feel less grabby actually slow/stop the car any differently than the stock pads is a question I would like answered. I switched to Axis deluxe brake pads on the roadster and they seemed to stop fine, but with less dust. I certainly preferred them to the stock pads, but could not say for sure whether they stopped the car within the same specs with regards to distance.