Car shakes when braking

arr0gant · 07-13-2009, 12:25 PM

Was driving on some back roads and noticed really bad shaking in the steering wheel when I brake. I was slowing down pretty hard from high speeds and now I notice shaking whenever I brake, albeit pretty subtle. I've never tracked my car and don't drive all that overly aggressive.

My car only has 8k miles so I can't imagine I would need new rotors. I have an appt to get it check out. Anyone have any idea what else it could be and If i'm gonna have to pay out of pocket?

M3ltdown · 07-13-2009, 12:32 PM

rotors should be covered for the first 4 years/50K miles.

itofigari · 07-13-2009, 01:30 PM

Quote:

Originally Posted by arr0gant

Was driving on some back roads and noticed really bad shaking in the steering wheel when I brake. I was slowing down pretty hard from high speeds and now I notice shaking whenever I brake, albeit pretty subtle. I've never tracked my car and don't drive all that overly aggressive.

My car only has 8k miles so I can't imagine I would need new rotors. I have an appt to get it check out. Anyone have any idea what else it could be and If i'm gonna have to pay out of pocket?

Hey man,
After my first track day, I had the same "problem" you are experiencing. Do not worry since in about 2 weeks, it will go away. The vibration is caused by break pad material attached to the rotors. After a few hot laps, the temperature on the stock pads will almost melt them and if you are not careful to let your brakes cool off, you might encounter worst problems. I cant imagine you heated up your brakes so much on the streets, but try not to brake so much when stopping after reaching high speeds...it is actually better to do hard , consecutive brakes than braking for prolonged periods since this will even bring more heat to the breaks.

grayshrk · 07-13-2009, 01:30 PM

Just a guess, but this sounds like a rotor issue that is typically caused by applying the emergency brake while the brakes are hot (e.g., complete a track session then apply emergency brake while parking). This is a common issue for people that track their cars. If you don't track your car but you do drive/brake hard, this can happen to you as well.

Subw00er · 07-13-2009, 01:32 PM

Quote:

Originally Posted by itofigari

Hey man,
After my first track day, I had the same "problem" you are experiencing. Do not worry since in about 2 weeks, it will go away. The vibration is caused by break pad material attached to the rotors. After a few hot laps, the temperature on the stock pads will almost melt them and if you are not careful to let your brakes cool off, you might encounter worst problems. I cant imagine you heated up your brakes so much on the streets, but try not to brake so much when stopping after reaching high speeds...it is actually better to do hard , consecutive brakes than braking for prolonged periods since this will even bring more heat to the breaks.

+1, this is probably what it is.

Dascamel · 07-13-2009, 02:30 PM

If you want to get them feeling better sooner, stop a few times hard from a high speed to wear off the pad material thats transferred to the rotors.

swiss_cornholio · 07-13-2009, 04:19 PM

Quote:

Originally Posted by Dascamel

If you want to get them feeling better sooner, stop a few times hard from a high speed to wear off the pad material thats transferred to the rotors.

Nope, doesn't work with the oem pads. If you want to avoid those problems in the future:

1) brake properly (short and hard)

2) buy the race pads from BMW. they are excellent but you have to get used to some squeaking...

kenwelch · 07-13-2009, 04:45 PM

Quote:

Originally Posted by grayshrk

Just a guess, but this sounds like a rotor issue that is typically caused by applying the emergency brake while the brakes are hot (e.g., complete a track session then apply emergency brake while parking). This is a common issue for people that track their cars. If you don't track your car but you do drive/brake hard, this can happen to you as well.

The parking (emergency) brake system uses a separate drum brake inside the rear rotors on the E9X M3's. The rear brake pads are not applied when using the parking brake. Using the parking brake when the rotors are hot will not be a problem with the M3.

Some other types of vehicles do use the rear brake pads for the parking brake.

spyderco10 · 07-13-2009, 04:57 PM

I noticed a vibration too when I braked from high speeds. That was a few months ago. It seems to have gone away by itself since then.

SS32 · 07-13-2009, 05:18 PM

Quote:

Originally Posted by kenwelch

The parking (emergency) brake system uses a separate drum brake inside the rear rotors on the E9X M3's. The rear brake pads are not applied when using the parking brake. Using the parking brake when the rotors are hot will not be a problem with the M3.

Some other types of vehicles do use the rear brake pads for the parking brake.

What a great/logical idea. I would still feel weird using the emergency brake after a session.

Dascamel · 07-13-2009, 08:07 PM

Quote:

Originally Posted by swiss_cornholio

Nope, doesn't work with the oem pads. If you want to avoid those problems in the future:

1) brake properly (short and hard)

2) buy the race pads from BMW. they are excellent but you have to get used to some squeaking...

Yes it does, after 4 days of tracking it stayed consistant, I did a few hard stops in succession from around 80 to zero, problem solved. For aggressive track days, I agree on better track pads. Now if you warped your rotors, this technique won't work. The vibration will return quickly.

skierman64 · 07-13-2009, 08:57 PM

I agree that it's probably pad transfer. It took 3 weeks of street driving for it to disappear after a track weekend, but I don't use my brakes real hard in my normal day to day driving.

arr0gant · 07-17-2009, 08:53 AM

Thanks everyone!! Turns out it was from driving on a bent rim, which I had replaced over a month ago. This warped the rotor, which had to be replaced, as well as a wheel hub.

TUNEDM3 · 07-18-2009, 07:17 AM

Quote:

Originally Posted by arr0gant

Thanks everyone!! Turns out it was from driving on a bent rim, which I had replaced over a month ago. This warped the rotor, which had to be replaced, as well as a wheel hub.

Dont see how the bent rim would warp the rotor? What a crazy answer they gave you, but whatever the case glad your car is fixed.

Speedtrap · 07-18-2009, 07:28 AM

I went for one track day, and had the same experience. Sent the car to the dealer, and they found that the offside disc has actually warped. They replaced both sides together with new pads.

arr0gant · 07-18-2009, 08:29 AM

Quote:

Originally Posted by TUNEDM3

Dont see how the bent rim would warp the rotor? What a crazy answer they gave you, but whatever the case glad your car is fixed.

They were kind of speculating. They never actually discussed it with me. I figured it made sense.

09E92M34ME · 07-20-2009, 06:01 PM

at least it's fixed

07-13-2009, 12:25 PM	#1
arr0gant Lieutenant 32 Rep 517 Posts Drives: 1996 911 Carrera Cab Join Date: Jun 2008 Location: St. Louis iTrader: (0)	Car shakes when braking Was driving on some back roads and noticed really bad shaking in the steering wheel when I brake. I was slowing down pretty hard from high speeds and now I notice shaking whenever I brake, albeit pretty subtle. I've never tracked my car and don't drive all that overly aggressive. My car only has 8k miles so I can't imagine I would need new rotors. I have an appt to get it check out. Anyone have any idea what else it could be and If i'm gonna have to pay out of pocket? __________________ 1996 911 Carrera Cabriolet 2006 Porsche Cayman S, 2004 M3 Vert, 2008 BMW M3 Sedan, 2001 911 Turbo, 2002 Porsche 911 C4S, 2004 Cadillac CTS-V, Porsche Boxster S
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07-13-2009, 12:32 PM	#2
M3ltdown Master Chief 19 Rep 641 Posts Drives: 09 e90 M3 JzB Join Date: Jul 2008 Location: NOVA iTrader: (0)	rotors should be covered for the first 4 years/50K miles.
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07-13-2009, 01:30 PM	#4
grayshrk Private 1 Rep 95 Posts Drives: 2008 Graphite E92 M3 DCT Join Date: Jul 2008 Location: SoCal iTrader: (0)	Just a guess, but this sounds like a rotor issue that is typically caused by applying the emergency brake while the brakes are hot (e.g., complete a track session then apply emergency brake while parking). This is a common issue for people that track their cars. If you don't track your car but you do drive/brake hard, this can happen to you as well.
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07-13-2009, 02:30 PM	#6
Dascamel Lieutenant Colonel 48 Rep 1,664 Posts Drives: 2008 e92 M3, 2010 e91 328i Join Date: Jul 2007 Location: Bakersfield, CA iTrader: (0)	If you want to get them feeling better sooner, stop a few times hard from a high speed to wear off the pad material thats transferred to the rotors. __________________ 2008 E92 M3 Jerez Black,DCT,Fox Red ext,Prem,Tech,19", ipod/usb, CF roof and trim 2010 E91 328i Space Gray,Black int, M sport, most options 2007 Montego Blue 335i (retired)
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07-13-2009, 04:57 PM	#9
spyderco10 Colonel 63 Rep 2,426 Posts Drives: AW E92 M3 6MT Join Date: Jul 2008 Location: Honolulu, HI iTrader: (0)	I noticed a vibration too when I braked from high speeds. That was a few months ago. It seems to have gone away by itself since then. __________________ “For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.” - John 3:16
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07-13-2009, 08:57 PM	#12
skierman64 Brigadier General 127 Rep 3,071 Posts Drives: E92M3-E46M3-E46Wagon-E89Z4-E36 Join Date: Dec 2006 Location: Greater St Louis Metro area iTrader: (1) Garage List 1994 325is Race Car [0.00] 2011 BMW Z4 [0.00] 1998 M3 Coupe [0.00] 2008 M3 Coupe [0.00]	I agree that it's probably pad transfer. It took 3 weeks of street driving for it to disappear after a track weekend, but I don't use my brakes real hard in my normal day to day driving. __________________ Invest Wisely...The best mod for your money?? BMWCCA high performance driver's school. The mod that lasts a lifetime and improves the performance of any car you drive[/LEFT]
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07-17-2009, 08:53 AM	#13
arr0gant Lieutenant 32 Rep 517 Posts Drives: 1996 911 Carrera Cab Join Date: Jun 2008 Location: St. Louis iTrader: (0)	Thanks everyone!! Turns out it was from driving on a bent rim, which I had replaced over a month ago. This warped the rotor, which had to be replaced, as well as a wheel hub. __________________ 1996 911 Carrera Cabriolet 2006 Porsche Cayman S, 2004 M3 Vert, 2008 BMW M3 Sedan, 2001 911 Turbo, 2002 Porsche 911 C4S, 2004 Cadillac CTS-V, Porsche Boxster S
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07-18-2009, 07:28 AM	#15
Speedtrap Lieutenant Colonel 57 Rep 1,798 Posts Drives: A very fast car :) Join Date: Sep 2008 Location: London iTrader: (0)	I went for one track day, and had the same experience. Sent the car to the dealer, and they found that the offside disc has actually warped. They replaced both sides together with new pads. __________________
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07-20-2009, 06:01 PM	#17
09E92M34ME Captain 70 Rep 920 Posts Drives: 2009 E92 M3 Join Date: Jul 2008 Location: VIRGINIA iTrader: (0)	at least it's fixed __________________ 09 E92 M3,AW/FR. MODS:Performane Kidney Grills,Side Gills,Exhaust Tips,BMW Performance Pedals,359 Satin Black GTS Wheels,275/35/19R & 255/35/19F PSS's,Dinan Stage I Suspension,Macht Schnell Spacers 12mmF,5mmR,Rear Fogs,Euphoria 6k,LCI Tails,LUX v3,OEM IND Painted Alpine White CF Performance Spoiler, Front Splitters, and Front Reflectors,Gloss Black Hood Vents,M Performance Steering Wheel.
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