Blue rings on brake disc/rotor? - Dealer blaming me?

[Sankekur]

how the hell does one "brake excessively" ??

pretty easily actually, with most road cars about 10 full on brake cycles (hard enough until just before the ABS kicks in) and the brakes will start to fade, that can be seen as excessively, as this is not what road car brakes are built for.

Surely, if the car brake system is original, you should be able to brake as hard as you like as often as you like without the brakes being negatively affected. If they burn blue or buckle or fade to buggery or squeal then it has to be a design flaw. That has to be BM's problem, not the owner/driver's problem. I'd look at the consumer protection act and see if there isn't a comeback to the dealership. It may be worth mentioning to them that you intend looking into that area if they don't want to co-operate in a reasonable manner. My 2c worth.

Not true at all, road car brakes fade pretty easily actually. And to my knowledge there are no brakes, or brake system in existence that allows you to brake "as hard and a often as you like". There are also other reasons why brakes your buckle and squeal that is not a design fault.

 

[Bemused]

how the hell does one "brake excessively" ??

pretty easily actually, with most road cars about 10 full on brake cycles (hard enough until just before the ABS kicks in) and the brakes will start to fade, that can be seen as excessively, as this is not what road car brakes are built for.

Surely, if the car brake system is original, you should be able to brake as hard as you like as often as you like without the brakes being negatively affected. If they burn blue or buckle or fade to buggery or squeal then it has to be a design flaw. That has to be BM's problem, not the owner/driver's problem. I'd look at the consumer protection act and see if there isn't a comeback to the dealership. It may be worth mentioning to them that you intend looking into that area if they don't want to co-operate in a reasonable manner. My 2c worth.

Not true at all, road car brakes fade pretty easily actually. And to my knowledge there are no brakes, or brake system in existence that allows you to brake "as hard and a often as you like". There are also other reasons why brakes your buckle and squeal that is not a design fault.

I'm not too sure that I buy that. The brakes have to perform to a standard that will allow continuous and safe use over the anticipated normal use period and if that entails using them within the confines of their design limit over an extended period, then they should be able to do so without disadvantage to the user.
Otherwise you could say, eg, that the gearbox broke because you accelerated too hard too often and therefore as the driver/owner, you have to pay for the gearbox repairs. No, the gearbox must be able to operate in the band of power delivery by the engine for the anticipated normal life cycle of the component without disadvantage to the owner/operator.

 

[Sankekur]

then you are very naive.

 

[rick540]

To try and mention something about brakes and constant use.

There is a design tradeoff here about how much thermal mass (required to absorb heat) and unsprung weight (Iron attached to the shock).

They can make a brake system that will never fade using massive heavy discs and handling will suffer badly, or they can make awesome handling with crap brakes that fade easily. they have to compromise between the two.

One solution is to use inboard brakes (not on the wheel but on the diff like the old Alfas used to) very clever.

Brakes will always eventually fade when used hard, don't underestimate the amount of energy required to bring a two ton car from 200kmh to standstill, virtually all the kinetic energy is converted to heat that has to be absorbed by 10/15 kg of iron and when it's hot it's really hot and needs significant cooling.

 

[Philip Foglar]

To try and mention something about brakes and constant use.

There is a design tradeoff here about how much thermal mass (required to absorb heat) and unsprung weight (Iron attached to the shock).

They can make a brake system that will never fade using massive heavy discs and handling will suffer badly, or they can make awesome handling with crap brakes that fade easily. they have to compromise between the two.

One solution is to use inboard brakes (not on the wheel but on the diff like the old Alfas used to) very clever.

Brakes will always eventually fade when used hard, don't underestimate the amount of energy required to bring a two ton car from 200kmh to standstill, virtually all the kinetic energy is converted to heat that has to be absorbed by 10/15 kg of iron and when it's hot it's really hot and needs significant cooling.

+1

Didn't old Jaguar's also have inboard disks on the rear axles?

 

[Sankekur]

Yup, from what I heard they did.

 

[frikkieh]

The old Audi 100's (early models) also had inboard brakes too. I had a 1976 100L model, but it changed by then.

 

[@ri]

Hi guys

Just an update:

Apparently the guy who told me that story was in no authority. Spoke to the service manager this time and they looked at the car and said they would replace them under MP straight away.

Just shows you how some clown in the workshop can make a terrible impression on the customers.

Will keep all information posted here in mind with the new discs and pads. Thanks.

 

[andrewbuch]

:thumbs: these workshop clowns think they run the place... (I know not all of them are, but it just takes 1 to ruin the dealers reputation)

 

[@ri]

That's true hey Andrew. At least I know which oke to avoid now there are some brilliant guys though, just have to specify that you want them to look at it

 

[Bemused]

That is good news indeed. Well done for sticking to your guns and glad it's sorted.

 

[@ri]

That is good news indeed. Well done for sticking to your guns and glad it's sorted.

:thumbs: Thanks mate.

 

[@ri]

Ok latest update.. And it's not good..

Picked up the car just now after they changed discs.

As I was driving on the highway, everything was fine until i suddenly felt a hard shuddering.. Didn't feel like it came through the steering wheel though.. Which makes me think it's more diff/drivetrain related :/

Sigh... Waiting for workshop guys to come out now.

What happens when your clutch goes? Same thing or not? Cos it feels weird when pulling off now too..

 

[Philip Foglar]

At what point is this shudder felt? Just cruising along, braking, accelerating?

 

[Nic_s]

Center bearing maybe?

 

[andrewbuch]

@ri I had the same thing when I replaced all my disks & pads.. I adjusted the handbrake too tight..

Did not happen when driving in town, & my first hiway trip at about 100 to 120 it happened.. was hectic shuddering...

slowed down but it was still there..

it was not through steering wheel..

put brakes to see if its that & still the same..

Pulled handbrake up a little & shudder was there like crazy..

once off hiway, drove a bit with handbrake up a bit.. it went away after a few days..

 

[moranor@axis]

@ri I had the same thing when I replaced all my disks & pads.. I adjusted the handbrake too tight..

Did not happen when driving in town, & my first hiway trip at about 100 to 120 it happened.. was hectic shuddering...

slowed down but it was still there..

it was not through steering wheel..

put brakes to see if its that & still the same..

Pulled handbrake up a little & shudder was there like crazy..

once off hiway, drove a bit with handbrake up a bit.. it went away after a few days..

lol why did you not adjust the hand brake... instead of driving it around a few days :fencelook:

 

[andrewbuch]

lol why did you not adjust the hand brake... instead of driving it around a few days :fencelook:

after that first hiway trip.. It only shuddered when I pulled the handbrake slightly when moving...

 

[@ri]

LOL Andrew although it could be that as I did ask them to adjust the handbrake?

We drove it back (mr blue rings guy came to pick me up LOL) , problem persisted when reaching about 120 and sometimes at lower speeds. Tyres are finished so will replace those to eliminate the problem - they reckon it's them. Hoping that's all.

Just seems a coincidence that it happens as soon as the car goes in to them. But no prob

Will change all Tyres and take it from there.

 

[Josh-ZN]

:nonono: oh no, sorry dude. Not having much luck. Do they actually test the cars properly before giving them back? And the main reason I moved from Audi to BMW was the lack of Audi service, or should I say non-existent Audi service!

Good luck man!