|
|
|
|
|
|
BMW Garage | BMW Meets | Register | Search | Today's Posts | Mark Forums Read |
|
BMW 3-Series (E90 E92) Forum
>
Issue With Geomet Rotors and Cool Carbon Brake Pads
|
|
12-05-2012, 04:32 PM | #1 |
Colonel
483
Rep 2,283
Posts |
Issue With Geomet Rotors and Cool Carbon Brake Pads
Hey Guys so I got the geomet slotted front rotors for my car and installed them about 1500 miles ago. I used the existing cool carbon brake pads on my car since I only installed them like 3000 miles prior to the new rotors so there was plenty of life left on them. Well they have been great thus far and now I have steering wheel wobble when i apply 40% or more brake at speeds around 30-70mph. Someone told me that it could be carbon buildup on the rotors making the surface uneven and that some heavy braking could help burn it off? Any suggestions on what I should do. Ive contemplated buying new brake pads to see if that will change anything. Thanks for any advice.
__________________
|
12-06-2012, 08:23 PM | #2 | |
Second Lieutenant
25
Rep 234
Posts
Drives: Estoril Blue F22 M235i
Join Date: Apr 2011
Location: Medford, MA
|
Quote:
|
|
Appreciate
0
|
12-06-2012, 09:30 PM | #4 | |
Private First Class
9
Rep 170
Posts |
Quote:
The answer is not to brake heavily - the transfer layer is built up when the pads meet the rotors at high temperatures, thus resulting in more pad material being deposited. In light use, when the pads don't heat up and transfer material to the rotors, it's actually possible to "unbed" the pads from the rotors, since the stopping forces are more friction than adhesion, and the friction burns off the transfer layer from the rotor. For street pads this "unbedding" doesn't usually result in a loss of stopping power, and a few hard stops will re-bed that pads. I suggest a few gradual "rolling stops" from 60 down to about 10, do not let the car stop with the brakes applied. Do this several times allowing the brakes to cool between stops by driving at a steady rate of speed without using the brakes. Then follow a normal bed-in process (see the articles I linked above) and see if that helps.
__________________
2007 E93 N54 Last edited by andrew_b; 12-06-2012 at 09:36 PM.. |
|
Appreciate
0
|
12-07-2012, 10:31 AM | #6 | ||
Colonel
483
Rep 2,283
Posts |
Quote:
I think I would have to agree, red stuff or Hawks in my future Quote:
Thanks for all your help guys
__________________
|
||
Appreciate
0
|
12-07-2012, 10:50 AM | #7 |
New Lifetime Replacement Policy
811
Rep 11,738
Posts |
Tim - sounds like you need to re-bed the pads.
The idea behind ruffing up the pad a little is to remove it's "bedded face" and help the re-bedding procedure. |
Appreciate
0
|
12-07-2012, 01:47 PM | #8 |
Colonel
483
Rep 2,283
Posts |
Any suggestion on where I should Re-bed the pads?
__________________
|
Appreciate
0
|
12-07-2012, 02:24 PM | #9 |
Captain
24
Rep 701
Posts |
....I did mine on a nearby subdivision where they're building new houses. There's a 3/4 mile stretch with only 1 traffic light and 1 stop sign. I did 10 65mph to 20mph stops and 5 45mph to 15mph stops and a 2 mile cool down. Try looking for areas where they're building new homes...perhaps an empty parking lot, or long stretch of road with moderate or little traffic, but never the freeway.
|
Appreciate
0
|
12-07-2012, 02:25 PM | #10 |
New Lifetime Replacement Policy
811
Rep 11,738
Posts |
Back roads with higher speed limits (45-55 MPH) are typically good locations for bedding brakes. Never bed brakes around busy areas, or where there is a chance of children running about.
|
Appreciate
0
|
12-11-2012, 09:49 PM | #11 | |
Guest
0
Rep n/a
Posts
Drives:
|
Quote:
Either way, trying to re-bed the pads/rotors probably won't do anything at this point, it's already too late IMO. It would be like trying to get the flat spot out of a tire by doing a burnout = not gonna happen. The only way that I've found to get a "high spot" out of a rotor caused by pad transfer is to swap the pads with aggressive race pads THEN do the bed in process with those. The Cool Carbons, or any other street pad for that matter, will not be aggressive enough to "knock down" that high spot given their rotor friendly compound. After the high spot is gone, you can switch back to your street pads. Do this (good idea if you have race pads laying around or can borrow a set), machine the rotors (terrible idea), or buy new rotors (only other option). Just my $0.02 |
|
Appreciate
0
|
Bookmarks |
Thread Tools | Search this Thread |
|
|