[TractionControlOff]

I'm at 400 miles on my new F30 335i and my brakes still seem to require a little more effort than they did on my E90 335i. Is this a break-in issue or are the brakes on the F30 just not as aggressive as the E90?

Oh, one other factor to consider - I had an MT on my E90 and I now have an 8AT on the F30.

btw - I'm not trying to start another F30 sucks thread. I absolutely loved my E90, but I actually like the F30 even more.

[Alpine435i]

Google the procedure on bedding in brakes. Unfortunately at 400 miles, you're well beyond the point of having them bed properly. It's likely they've been heat cycled several times, so this procedure will not benefit you.

But for others who don't know... http://www.zeckhausen.com/bedding_in_brakes.htm

I realize that this sort of break-in procedure is nowhere to be found in the owner's manual, so most will dismiss it. The owner's manual recommends "no hard braking" for the first xxx miles...but that's the worst thing you can do for your brand new brakes. But then again, the type of person who's knowledge is only as deep as an owner's manual likely won't know or feel a difference between properly bedded brakes...

[nicknaz]

Agreed, you need to hammer down on the brakes in a controlled manner to get a good transfer layer onto the rotors.

And I personally need to use the engine hard to seat the piston rings properly.

Best solution.. track day ASAP after getting the new car

[TBLM235X]

I wish I had seen this post earlier! I just had Mperformance brakes installed and have just about 400 miles on them now and followed the directions that came with the brakes. They even placed a BMW hangtag on my shifter that advised no hard stops for the first 125 miles. On the other hand, I'm not sure there would be any public roads around here that are near the dealer or me where I could actually perform this type of break-in…by the 2nd or 3rd slow down, someone would be on my ass.

[TractionControlOff]

Originally Posted by Alpine435i

Google the procedure on bedding in brakes. Unfortunately at 400 miles, you're well beyond the point of having them bed properly. It's likely they've been heat cycled several times, so this procedure will not benefit you.

But for others who don't know... http://www.zeckhausen.com/bedding_in_brakes.htm

I realize that this sort of break-in procedure is nowhere to be found in the owner's manual, so most will dismiss it. The owner's manual recommends "no hard braking" for the first xxx miles...but that's the worst thing you can do for your brand new brakes. But then again, the type of person who's knowledge is only as deep as an owner's manual likely won't know or feel a difference between properly bedded brakes...

That's interesting and if you do it right, it probably does slightly enhance your braking. However, I actually was more aggressive with my break-in than last time. I'm now at 800 miles and I think I have figured out the difference. I have never driven an automatic (other than SUV's, etc) and I am pretty confident what I am experiencing is the effect of the engine working against my braking efforts. Also, especially in Sport mode I notice the variability of the engine braking as it is downshifting. Of course w/ my old 6MT I had the clutch down and there was a more smooth stop with no resistance. I also miss the slight handling advantage of a clutch down turn. I'll try to create a thread with a detailed comparison of 6MT and 8AT and these will be 2 of the negatives against 8AT. Overall, I am much happier than I expected to be with the 8AT.

[Alpine435i]

Originally Posted by TBLM435

They even placed a BMW hangtag on my shifter that advised no hard stops for the first 125 miles.

Yeah that's complete BS. BMW simply can't outline proper bedding procedure for too many reasons, just like proper engine break-in procedure. So, like any manufacturer, they simply take the easy way out and recommend some nonsense to make the end user feel as they're accomplishing something.

At the end of the day however, the difference is not significant. These aren't race or specialty high performance brakes (or engines) so it really doesn't matter.