DIY: Brake Pad Replacement DIY

MTROIS wrote

Following a very satisfying brake pad job in an hour and a half today, I'd like to add two things:

- first, instead of "suffering" with a regular 7mm allen key, I highly recommend getting the following hex bit that you will be able to use with your ratchet... and save loads of time: http://www.bimmertools.com/7MM-Stubby-Hex-Brake-Bit-for-BMWs-p/ahbmw307.htm

- also, I have come to realize that you can easily remove the anti-rattle springs without any tools!! Just push in the direction of the axle and gently lift the back... it comes right out and goes right back in this way.

The first time, it took me probably 3 hours or so to change the pads and now it is a real piece of cake. On this high note.... I am back to the American Le Mans series....

pix plz for the 2nd part ur talking about

MTROIS wrote

Following a very satisfying brake pad job in an hour and a half today, I'd like to add two things:

- first, instead of "suffering" with a regular 7mm allen key, I highly recommend getting the following hex bit that you will be able to use with your ratchet... and save loads of time: http://www.bimmertools.com/7MM-Stubby-Hex-Brake-Bit-for-BMWs-p/ahbmw307.htm

- also, I have come to realize that you can easily remove the anti-rattle springs without any tools!! Just push in the direction of the axle and gently lift the back... it comes right out and goes right back in this way.

The first time, it took me probably 3 hours or so to change the pads and now it is a real piece of cake. On this high note.... I am back to the American Le Mans series....

Thanks for the stubby hex bit...it means I can use my electric impact wrench (as opposed to driver) now!

FruitCake wrote

pix plz for the 2nd part ur talking about

I already covered these two items in my rewrite of the procedure (please see the pdf). I did recommend a pliers instead of hands though, just because it's less messy and provides better grip.

There are a couple of things I'd change in another rewrite however; 1) I'd suggest jacking up all four corners, rather than one side at a time. This saves a lot of time and let's you bleed all four corners one after the other (starting farthest from master cylinder and ending closest to it); and 2) I'd recommend using a power bleeder to better do the job solo. I've gotten the whole procedure down to an hour even now

Does everyone replace their rotors when they change the brake pads? I've been told by some BMW techs that you should buy new rotors everytime you change the pads, then other techs that you only change them if you need to. My M3 has 51k on it now and it needs brakes, so I'm debating if I need to change the rotors out or not.

WCM3 wrote

Does everyone replace their rotors when they change the brake pads? I've been told by some BMW techs that you should buy new rotors everytime you change the pads, then other techs that you only change them if you need to. My M3 has 51k on it now and it needs brakes, so I'm debating if I need to change the rotors out or not.

I am not a mechanic so take this with a grain of salt. I replaced the brake pads on my S2000 multiple times w/o changing the rotors and did not have an issue. I always checked the rotors to ensure they weren't too thin and checked to make sure there weren't any scoured areas.

WCM3 wrote

Does everyone replace their rotors when they change the brake pads? I've been told by some BMW techs that you should buy new rotors everytime you change the pads, then other techs that you only change them if you need to. My M3 has 51k on it now and it needs brakes, so I'm debating if I need to change the rotors out or not.

No, you do not need to replace rotors every single time you buy pads.

Usually, you can resurface rotors, but drilled rotors, no.

If your at 51k on stock rotors however, they may need to be changed. But what they said is complete bs.

When pushing the piston back with the c-clamp, do we need to remove the cap on the brake reservoir or is ok to leave it on?

Why are you balking at replacing rotors at 51K? Trying to get another 1K out of them? You drive an M. Maximize your advantage.

FrenchBoy wrote

Thanks Lucid. Great write-up.

One question about the anti-rattle clip. I am very familiar which changing brakes pads as I have done it many time on my E46 325Ci. Overall, seems to be a similar setup.

The anti-rattle clip looks quite different though and seems trickier to remove. Do you have input or close-up shots on how it is attached and how to removed.

I am installing Carbotech XP10 in about a week for a track day.
Thanks

Regarding the carbotechs - I've had great results with xp12's with my v8 miata - but i think you can't just swap pads since carbos require resurfacing the rotor because the bedding process leaves a film on the surface in order for it to work properly.

When you say "Remove the pad wear sensor. It is clipped onto one of the brake pads. Just pull on it and it will come out. The chances are the tensioner clip will remain in the pad. Make sure to get it. They are not sold separately, and if you lose it, you'll need to buy a new sensor."

Are the pad wear sensors reusable?
Are the tensioner clips removable and essential?
When you swap to track pads, do you guys attach a sensor? if not, what happens? do you just receive a brake light? aka are pad wear sensors necessary?

Thanks

MK599 wrote

When you say "Remove the pad wear sensor. It is clipped onto one of the brake pads. Just pull on it and it will come out. The chances are the tensioner clip will remain in the pad. Make sure to get it. They are not sold separately, and if you lose it, you'll need to buy a new sensor."

Are the pad wear sensors reusable?
Are the tensioner clips removable and essential?
When you swap to track pads, do you guys attach a sensor? if not, what happens? do you just receive a brake light? aka are pad wear sensors necessary?

Thanks

Are the pad wear sensors reusable - Yes.
Are the tensioner clips removable and essential - Yes and yes, unless you want or care about warnings/errors on the console.
Re: Track pad swap, do we attach? - I no longer do. See below.
If not attached - you get an computer error. Car works as normal.

I re-used my sensors until I lost the little metal tensioner clip or the cable system failed in some fashion (they are cheap $18-$22). I eventually got so sick and tired of having to frig around with the cable system that I have since disconnected them front and back and simply cut off the sensor to expose both wires, twist them together (system shorted out to believe all is well) tape them off and tie wrap them up. Only makes sense to do this if you track often and are very aware of your pad usage. Otherwise I dont recommend anyone doing this.

Does anyone know the torque specs for the caliper bolts?

jgalaxy wrote

I eventually got so sick and tired of having to frig around with the cable system that I have since disconnected them front and back and simply cut off the sensor to expose both wires, twist them together (system shorted out to believe all is well) tape them off and tie wrap them up.

I'm stumped why BMW doesn't use the proven method of audible wear indicators on the pads, like all other freaking cars in the market . They try too hard to be different... and many times with non-desirable results. Not having an 'off' HVAC button is another example. Or a freaking dipstick. You get my point . Hey, I thought that just putting the sensor aside (taped up somewhere) didn't trigger any faults, no? They're supposed to trigger a fault when the sensor is grounded after being grinded down by the rotor. How the hell does it 'know' it's attached to the clip? Thx.

m3heaven wrote

Does anyone know the torque specs for the caliper bolts?

30N.m or 22lb.ft

Thanks for sharing, and thanks for taking the time and efforts in providing us pics...

useful DIY and very easy. switched to my ds2500 pads this morning, removed my dust shields for extra cooling with my gt4 ducts and put on my track wheels so set for the season!

Compared to my Stoptechs...What a PIA! And thanks for the DIY!

chriszeh wrote

useful DIY and very easy. switched to my ds2500 pads this morning, removed my dust shields for extra cooling with my gt4 ducts and put on my track wheels so set for the season!

How did you get rear anti-rattle spring out？ I tried so hard and is not working..so I only changed front pads.

the rear was super easy i think i may have just used my hand. the front was harder for me.

chriszeh wrote

the rear was super easy i think i may have just used my hand. the front was harder for me.

Really！How did you do it by your hand. Took me half hour and still can not get it out.

zhouzitao wrote

Really！How did you do it by your hand. Took me half hour and still can not get it out.

By hand it is almost impossible for me. I use a screwdriver. You put it in one of the holes and use it as a lever pushing the metal away from the center of the hub. This way you can wiggle one of the hooks out. The second one is then easy.

The fronts are easy and can be done by hand.

r53s65e90 wrote

By hand it is almost impossible for me. I use a screwdriver. You put it in one of the holes and use it as a lever pushing the metal away from the center of the hub. This way you can wiggle one of the hooks out. The second one is then easy.

The fronts are easy and can be done by hand.

weird i had the opposite experience. the fronts took me about half an hour to figure out and my rears just popped out.