E46 BMW 330CI Brakejob: Grassroots Motorsports forum: Grassroots Motorsports Magazine

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June 22, 2010 10:04 a.m. oobert None

Hey guys, long-time lurker here!

My cousin has had this E46 BMW convertible for a while now. Recently it actually was put out of commission due to some electrical problems (something about the cluster getting all schizzoid). It was out of commission for a while but she recently got it back on the road.

She's complaining about some vibration that the car's making while she's braking. I'm assuming that the brake rotors are warped.

I should probably check out the car, but I really haven't had the time. I honestly am a huge noob when it comes to cars and such but I'm eager to learn.

Is there anything that I should know about replacing the brakes on this car? Best place to buy parts? Anything that I should replace / reset while everything's off? In actuality, It'd be nice to have a play-by-play (work instructions), but I don't want to ask too much of you guys.

One of my friends is actually going to help me with this, and he's a little bit more versed in car repair than I am (although not by much).

Thanks!

Alex
June 22, 2010 10:24 a.m. stuart in mn SuperDork

I don't know for sure about the e46 but it could be a worn control arm or thrust rod bushing - that's a common source of vibration on braking with older BMWs like mine.
June 22, 2010 10:42 a.m. grimmelshanks Reader

^my dads e28 does that. in time were gonna put all new bushings in it
June 22, 2010 10:49 a.m. 02Pilot Reader

Unless your cousin rides the brakes incessantly or tracks the car, the likelihood of the discs being warped is pretty low. There's a lot of brake in those cars, and the discs are hard to warp (though there are some crappy aftermarket pieces that might be more prone). The bushings are a lot more likely; they will require replacement on basically every BMW after about 8-10 years of normal use.
June 22, 2010 11:44 a.m. oobert New Reader

She definitely doesn't do any track time. I've heard that the brakes are pretty thick on them so this makes sense.

I'll look into the bushings. I'm pretty sure it's only a 2005 but I need to doublecheck. As far as parts go, any recommendations for getting some quality parts? I've heard of pelicanparts.com, but any other quality places?
June 22, 2010 11:55 a.m. Soma007 Reader

Pelican Parts is my standard go to place for most BMW parts. You can also try Ebay, just make sure they are quality parts. For suspension parts I'd stick with OEM (Lemforder) or Meyle.

Check bimmerforums.com or e46fanatics.com and you should be able to find a DIY walkthru on both the LCA bushings and brakes. The brakes are really not any different than most other cars. The only catch is that if the brake pad warning light is lit up on the dash then you need to replace the brake pad sensors to make it go away.
June 22, 2010 3:11 p.m. ansonivan Reader

oobert wrote: It was out of commission for a while but she recently got it back on the road.

She's complaining about some vibration that the car's making while she's braking. I'm assuming that the brake rotors are warped.

Probably rust build up from sitting, she may have worn control arm bushings/control arms also but the pads/rotors would be the cheaper place to start.

Pelican/bimmerparts are both good. Don't waste money on drilled/slotted rotors. Basic Zimmerman or Brembo are fine.

If the pad wear sensor tripped you'll need to replace the sensor (buy a new one either way) and leave the ignition in the "run" position without starting the car for one minute to reset the light.
June 23, 2010 9:37 a.m. motomoron Reader

Verify how much rotor and pad remain. If the rotors are clean check for runout w/ a dial indicator. Grease all 8 caliper pins, reassemble.

I use OEM rotors on a 90% track e36 M3 and they've worn like...ummm...cast iron w/ Hawk HT10s for the better part of 2 years and Performance Friction 06 (F) and 97 (R) of late.

For a car that won't be savaged the way mine is Brembo replacement rotors are fine. Axxis makes some nice, affordable pads.

And don't forget to grease those caliper slider pins...