Brake DIY and General Questions

Hello,

I have a 323ci with about 47,000 miles and I think it's time to change the brakes for the first time. A friend of mine works at an independent BMW shop and told me to wait for the brake light to come on the dash before I change them. I've been waiting for the light to come on for a few thousand miles already, and am starting to think it's gonna come on soon. Question is, when do these cars normally need a first brake change? Also, i've been looking for a DIY on how to change the rotors and pads, but had little luck. I know how to bleed brakes and such, so that will not be a problem.

Then the question on what brand fluid, and parts to use. What brake fluid are you guys using in your cars? I want to stick with OEM BMW brake pads and rotors when I make this change. Keep everything simple, no aftermarket parts. Finally, any special tools needed? I have metric/standard tool sets, but I know sometimes there are wierd "special" tools needed.

Thanks

I'll be very brief.
For the DIY, click on the TECH section up above; for parts go with OEM on the rotors and aftermarket for the pads (dustless is what you want, no matter what the brand: PBR, etc, etc). You will know your brakes need replacement when the warning light shows up on the dash or if you don't want to wait anymore, do a visual inspection. For brake fluid, go aftermarket.

As far as tools, you will not need anything special, your metric tools will do the job.

Good luck.

Thanks!! I never knew that section of the forum exhisted!!

Awesome, that will work out just great. Alex, do you know off hand the brand/type rotors and pads the dealer uses, and where I can get them? I want to put back the exact same parts that are comming off. The factory pads do create a lot of dust, but I dont mind cleaning the wheels.

^You're welcome. As far as the OEM brand, I'm not sure what they used but I think I read somewhere that they used ATE for the rotors. The best places to order OEM stuff off of are Circle BMW in Jersey or Pacific BMW on the West Coast. Give those 2 a call to see about prizes.

www.circlebmw.com
www.pacificbmw.com

I will highly recommend these pads, though, since the prize could be cheaper than OEM, not to mention the pros:
http://www.zeckhausen.com/axxis_pads.htm

Last question!

Someone told me that when you change brakes on these cars, (BMW's) you must change the rotors, AND the brake pads together. Is this correct?

Some cars you can machine down the rotors and simply purchace new brake pads, are BMW's like this?

Thanks

BMW's should have both pads and rotors replaced at the same time. I know there are people who have just replaced pads, though.

BMW's should have both pads and rotors replaced at the same time. I know there are people who have just replaced pads, though.


Why??

I read somewhere that OE BMW rotors are designed to wear down like the pads. So when your pads are gone, they're also a good indicator that you need to replace your rotors.

It's annoying especially when shops charge about $10 to turn (resurface) a rotor.

If anyone reads this thread, can you recommend a way to loosen the 6-mm hex screw holding the rotor to the wheel hub? I gave it a few test pulls this afternoon and had no luck. I soaked it w/ PB Blaster as well.

all rotors are designed to wear down. The pad should wear faster than the rotor. Instead of replacing them every time it better to measure them to see how thin they are. Rotors should have a min thickness stamped on them.

when you take them to a machine shop they will measure them and tell you if they are machinable.

if you don't go metal-to-metal, you don't really need to turn them. just measure them if you want, then throw the pads on...

Originally Posted by leej323

IIf anyone reads this thread, can you recommend a way to loosen the 6-mm hex screw holding the rotor to the wheel hub? I gave it a few test pulls this afternoon and had no luck. I soaked it w/ PB Blaster as well.

Use a personal sized torch gun. That along with WD40 has worked for me in the past when dealing with stubborn bolts and such.

Oh another thing that you can try too is use a metal pipe on the Allen wrench as leverage.

I used ATE brake fluid. They have two choices: ATE Blue and ATE Gold. I believe the different colors are when you change / bleed the brakes, you can see when the fluid has been probably changed / bled. This is assuming that you use Blue first and then Gold the next time, or vice versa.

I am almost through a second set of pads, w/out replacing the rotors. They have a big ridge on the outside, and are looking very thin right now. But - no warping and braking performance is still excellent. I wouldn't track it for sure, though. YMMV.

Get a set of hex-head sockets to loosen the allen bolts.

What type of brake fluid is used in the e46?

I just changed the rear on mine today. The light did not come on but I could tell they were pretty thin. I measured the remaining material and it was 3mm. This is pretty thin. Do the visual if you can see them thru your wheels.