Causes of Brake Fade??

[CarbonBlackM5]

My brake issues continue. After getting the discs swapped a few months ago under warranty I have some juddering again under braking. I am also experiencing very bad brake fade and not even when used in anger.

Im going to get it booked in but wanted to know what could be causing this. The pads were replaced in April (about 8K ago) and it had an Insp II at the same time so would the brake fluid have been replaced when this was done?

Any help would be appreciated so I can be armed when it goes in.

[Quinten]

Brake fluid is not part of Inspection II, as it needs replacing every 2 years

[jon-]

What sort of brake fade? Pedal getting longer, or that you just can't push down hard enough on a firm pedal?

[CarbonBlackM5]

Pedal travel is fine, just lack of stopping power/bite.

[jon-]

The only time I've experienced this is either with cold race pads, cheap pads, or when the pads have glazed from overheating then cooling down too quickly or light use.

I would suggest either replacing the pads, or getting the pressure in the braking system tested.

If you're not a hard driver you could also go out and totally cook the pads to see if that beds them into the new discs a little.

If it was your brake fluid you'd likely have pedal issues.

[TEKNOPUG]

What procedure was used to bed the new pads in?

[CarbonBlackM5]

None to speak of. I am aware of the bedding in method used on the M5 Board and tried this with my last set of discs before they were exchanged by BMW for being warped.

I am thinking of carrying it out again but havent been able to do so due to the st weather. Now that it has warmed up I might give it a go to see if there is any deposits on the pads.

[TEKNOPUG]

Have a read here:

http://www.stoptech.com/tech_info/wp_bedincontents...

and here:

http://www.stoptech.com/tech_info/wp_padremoval.sh...

as they may differ from the M5board methods.

[Frik]

Do you do a lot of motorway miles?

[CarbonBlackM5]

TEKNOPUG said:

Have a read here:

http://www.stoptech.com/tech_info/wp_bedincontents...

and here:

http://www.stoptech.com/tech_info/wp_padremoval.sh...

as they may differ from the M5board methods.

Yes this is the method I meant, I have tried it before and will give it ago again before I take it in.

No, dont do many motorway miles, mainly town work but I always make sure I try and avoid deposit build up by not leaving my foot on the brakes when I come to a stop. Maybe it needs a good old Italian tune up but my worry is that something is warping the discs but cant see what would.

[jon-]

CarbonBlackM5 said:

my worry is that something is warping the discs but cant see what would.

Have you done the old fashioned blat it down a motorway for a few miles, try and come to a stop without using the brakes (or only very lightly) then feel the temperature of each wheel? This will tell you if you have a lazy caliper.

[CarbonBlackM5]

jon- said:

CarbonBlackM5 said:

my worry is that something is warping the discs but cant see what would.

Have you done the old fashioned blat it down a motorway for a few miles, try and come to a stop without using the brakes (or only very lightly) then feel the temperature of each wheel? This will tell you if you have a lazy caliper.

Nope but I will, worth a try.

[Mr_Dave]

I replaced the disk/pads on my M3 with genuine stuff from the stealer as they were well worn. Only a few thousand miles later I was getting a nasty judder under medium/hard use and general naff breaking performance. It felt like the disks were warped, the vibration was so bad, I had to really hold on to the steering wheel. I tried a few things, removed the pads and cleaned them up, fluid etc. My calipers were also new....

I ended up just changing the pads to some Performace Friction items, job done! They did take a good 500 miles to come up to spec though...! That was 10k miles ago and it still stops on a sixpence

I'm with Jon-, naff/glazed pads

[CarbonBlackM5]

Well its booked in on Wednesday but on Friday I took it for a blast along a Dual carriage way to check the calipers and there was no evidence of the wheels getting hot.

The tyres were getting hot though and steam was coming off them due to the wet roads (this was when I was parked and checking the wheels).

They were hotter on the inside edges so I am suspecting the bushes (although the brake reaction bushes were changed not long ago). There is no evidence of the tracking being out and I checked the pressure a couple of weeks ago so not sure what else it could be. The fade was there too though so Im hoping they will get to the bottom of it on Wednesday.

[Lostprophet]

In reference to the OP, the cause of Brake fade?


Braking.

[CarbonBlackM5]

Lostprophet said:

In reference to the OP, the cause of Brake fade?


Braking.

Ha, no st sherlock.

Thanks for your help...not

[Lostprophet]

sorry, a dull moment at the office. I had nothing else but to crack stupid jokes!