Car Juddering after braking at speeds

Speedtrap · 03-09-2009, 02:23 PM

I was noticing it just last week, that when I brake at speeds; the car judders (can feel the vibration on the steering). My car has only done 2600 miles, and I have only taken it only once to Abingdon trackday; and so could not be a warped disc or a cracked disc? Could it? Or maybe it has not been broken in properly? maybe the deposits begins to transform into cementite?

I normally drive like pipe and slippers as well.

Have booked myself into Scotthall to have it checked out this Friday.

Anyone experienced this on their car with little mileage?

Cheers.

E92Fan · 03-09-2009, 02:44 PM

Quote:

Originally Posted by Speedtrap

I was noticing it just last week, that when I brake at speeds; the car judders (can feel the vibration on the steering). My car has only done 2600 miles, and I have only taken it only once to Abingdon trackday; and so could not be a warped disc or a cracked disc? Could it? Or maybe it has not been broken in properly? maybe the deposits begins to transform into cementite?

I normally drive like pipe and slippers as well.

Have booked myself into Scotthall to have it checked out this Friday.

Anyone experienced this on their car with little mileage?

Cheers.

Juddering from braking at speed indicates one of two things - warped disc from overheating (which is possible after a trackday) or pad imprint on the disc leading to an imperfect surface.

The way to find out which one it is is to try and deglaze the discs - find an empty stretch of road, accelerate to 40mph, then brake hard in a straight line to 10mph - do not brake to a standstill. Immediately get on the gas again and accelerate to 50mph. Brake hard again to 10mph, then immediately get on the gas to 60mph. Do two or three repeats of hard braking from 60mph to 10mph, then drive normally without braking for a few miles to cool the brakes.

This process will deglaze the discs from having any imperfect pad imprint. If braking thereafter is still juddery, the likelihood is the discs are warped.

Speedtrap · 03-09-2009, 02:49 PM

Thanks mate

Appreciate the help.

booforty · 03-10-2009, 04:54 AM

Good tip Tony!

biscuits · 03-10-2009, 05:34 AM

Great advice as always Tone....

My discs have 18k miles on them now and I do get a bit of a noise when using them hard, but this apparently is caused by the drilled holes becoming a bit clogged up with brake dust. There is no juddering or vibration in the steering wheel, just audioble noise... I was concerned at first, but a collegues 996C4S is the same.

My instinct is no matter what condition your disks are in the dealer will claim "harsh use, improper warming up before such use.... and the disks are warped"... I guess a lot depends on your dealers honesty. (did I just use dealer and honesty in the same sentence ?!)

E92Fan · 03-10-2009, 05:40 AM

Quote:

Originally Posted by biscuits

Great advice as always Tone....

My discs have 18k miles on them now and I do get a bit of a noise when using them hard, but this apparently is caused by the drilled holes becoming a bit clogged up with brake dust. There is no juddering or vibration in the steering wheel, just audioble noise... I was concerned at first, but a collegues 996C4S is the same.

My instinct is no matter what condition your disks are in the dealer will claim "harsh use, improper warming up before such use.... and the disks are warped"... I guess a lot depends on your dealers honesty. (did I just use dealer and honesty in the same sentence ?!)

The noise generally is either the pad wearing down, or the holes becoming clogged as you've said. And as you've said, dealers will use every which way to get out of replacing discs, especially on a car like an M3. However, as you well know there are some dealers who are a little more understanding than others

biscuits · 03-10-2009, 07:38 AM

Quote:

Originally Posted by E92Fan

The noise generally is either the pad wearing down, or the holes becoming clogged as you've said. And as you've said, dealers will use every which way to get out of replacing discs, especially on a car like an M3. However, as you well know there are some dealers who are a little more understanding than others

If I'm bored one Sunday, I might get the battery drill out and clean all the holes out...

xenon · 03-10-2009, 07:53 AM

Quote:

Originally Posted by biscuits

If I'm bored one Sunday, I might get the battery drill out and clean all the holes out...

Air-line is easier and you don't have to bother your arse taking the wheels off. Don't breathe it in though....

biscuits · 03-10-2009, 07:57 AM

Quote:

Originally Posted by xenon

Air-line is easier and you don't have to bother your arse taking the wheels off. Don't breathe it in though....

Might ask the guys to do this while it's in having the exhaust fitted next week then...

Speedtrap · 03-10-2009, 03:45 PM

Quote:

Originally Posted by biscuits

Might ask the guys to do this while it's in having the exhaust fitted next week then...

Who is doing your exhaust Paul?

And whats the setback?

biscuits · 03-11-2009, 04:38 AM

Quote:

Originally Posted by Speedtrap

Who is doing your exhaust Paul?

And whats the setback?

BMSport are doing the exhaust. I'm getting a deal as they will have had my car for two weeks to use as a template

Not sure what the finished price will be, but I'm sure it'll be competative to other systems out there.

Can't frekin wait !

03-09-2009, 02:23 PM	#1
Speedtrap Lieutenant Colonel 57 Rep 1,798 Posts Drives: A very fast car :) Join Date: Sep 2008 Location: London iTrader: (0)	Car Juddering after braking at speeds I was noticing it just last week, that when I brake at speeds; the car judders (can feel the vibration on the steering). My car has only done 2600 miles, and I have only taken it only once to Abingdon trackday; and so could not be a warped disc or a cracked disc? Could it? Or maybe it has not been broken in properly? maybe the deposits begins to transform into cementite? I normally drive like pipe and slippers as well. Have booked myself into Scotthall to have it checked out this Friday. Anyone experienced this on their car with little mileage? Cheers. __________________
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03-09-2009, 02:49 PM	#3
Speedtrap Lieutenant Colonel 57 Rep 1,798 Posts Drives: A very fast car :) Join Date: Sep 2008 Location: London iTrader: (0)	Thanks mate Appreciate the help. __________________
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03-10-2009, 04:54 AM	#4
booforty Major General 337 Rep 8,811 Posts Drives: E92 M3 Join Date: Mar 2005 Location: London, UK iTrader: (0) Garage List 2008 E92 M3 [0.00]	Good tip Tony!
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03-10-2009, 05:34 AM	#5
biscuits Dimmer than a dim thing 80 Rep 1,291 Posts Drives: M4 GTS, EQC, X5 40d, simrig Join Date: Oct 2008 Location: UK iTrader: (0) Garage List 2016 BMW X5 (F15) 4 ... [0.00] 2016 BMW M4 GTS [10.00]	Great advice as always Tone.... My discs have 18k miles on them now and I do get a bit of a noise when using them hard, but this apparently is caused by the drilled holes becoming a bit clogged up with brake dust. There is no juddering or vibration in the steering wheel, just audioble noise... I was concerned at first, but a collegues 996C4S is the same. My instinct is no matter what condition your disks are in the dealer will claim "harsh use, improper warming up before such use.... and the disks are warped"... I guess a lot depends on your dealers honesty. (did I just use dealer and honesty in the same sentence ?!)
	Appreciate 0 Quote