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      09-15-2018, 04:03 PM   #1
Estoril Blue 116d
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M-Sport brakes... Loooong pedal travel

Have any of you experienced this?
The pedal travel is way too long and the time it takes for the brakes to grip is unbelievable long. And semi-dangerous too.

So when the brake is pressed down, it travels 2-3 inches before anything happens. When the brakes finally grip it's a decent grip but I'm just afraid to really throw the anchor and use all of that power of the 340mm discs and 4 piston caliper. Also there is a kinda "bad" feel to the brakes, like they are on their last chapter. Now the thing is, they're not. The pads at the rear brakes are within their limits, and the computer says 2900km's (although I don't care much about this). They will be replaced but they hold some material still. The fronts are good, there's a 1mm wear edge on the discs but nothing bad at all. Pads look newish.

What do you think? I suspect there is a lot of air in the system and the brake fluid is over due to having a change. Should have been changed this june. Factory filled brakefluid I would assume...

What's your experience? Can someone relate?
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      09-15-2018, 05:11 PM   #2
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mine was due for service in 2000 km for rear brake pads last week and the feel was exactly the way as you described. When we removed the pads they were looking like thin paper. Now braking feels a bit more solid than what it was but it definitely needs brake fluid change. It should be changed every three years. brake fluid is not exactly something that is "consumed" by brake system. It just loses is viscosity due to heat.
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      09-15-2018, 09:54 PM   #3
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My M-Sport brakes are fine, but I have had a lot of experience with brake issues on other brakes earlier.

-Air in the brake fluid will cause a spongy/springy feel and longer pedal travel. Pumping the pedal will not help. It never gets really firm.
-Old brake fluid feels fine up to a point when it boils, and can cause sudden brake loss.
-"Pad knock back" can cause the pads to go away from the discs. First pedal application is scary, with very long travel. Braking again feels fine.
-Overheated pads can become soft and slippery. Typical symptoms are long pedal travel and increased pedal effort. After some driving (a few days), the outer layer of the pads will wear away, and the pedal feel goes back to normal.
-Glazed pads can also happen for other reasons than overheating, like driving in a lot of road salt with too long time between braking hard.

Sometimes the brakes can be fixed by running a bedding procedure. Find a deserted road, and repeat braking from around 100 km/h - 20 km/h, 8-10 times with brisk acceleration in between. Then keep driving for about 10 minutes without touching the brakes. Do not stop during the procedure. Notice that some people get nauseous doing this, and make sure no cars are following close behind you.
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      09-15-2018, 11:40 PM   #4
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Brake fluid is supposed to be changed every 2 years. The first time I wondered they told me it was all right to keep it for the third year. This time (the fifth year) they threatened me brake fluid warning was about to pop up and failed to explain why 3 years had been all right previously (did those reset it regarding the warning?).
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      09-16-2018, 03:48 AM   #5
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Quote:
Originally Posted by eray View Post
mine was due for service in 2000 km for rear brake pads last week and the feel was exactly the way as you described. When we removed the pads they were looking like thin paper. Now braking feels a bit more solid than what it was but it definitely needs brake fluid change. It should be changed every three years. brake fluid is not exactly something that is "consumed" by brake system. It just loses is viscosity due to heat.
Thx for replying. My car is somewhat older than 5 years now, and I don't know if it ever had a brake fluid change? I will go out and check that in the service book.
But yeah I suspect the brake fluid is pretty bad and black, and I honestly hope there's air in the system and that's the culprit. New parts for the M-Sport brakes are insanely overpriced at the dealers, and even though I can source them at 1/3 of the that price the parts are still pricey.
Fluid probably looking like this:


Quote:
Originally Posted by ovekvam View Post
My M-Sport brakes are fine, but I have had a lot of experience with brake issues on other brakes earlier.

-Air in the brake fluid will cause a spongy/springy feel and longer pedal travel. Pumping the pedal will not help. It never gets really firm.
-Old brake fluid feels fine up to a point when it boils, and can cause sudden brake loss.
-"Pad knock back" can cause the pads to go away from the discs. First pedal application is scary, with very long travel. Braking again feels fine.
-Overheated pads can become soft and slippery. Typical symptoms are long pedal travel and increased pedal effort. After some driving (a few days), the outer layer of the pads will wear away, and the pedal feel goes back to normal.
-Glazed pads can also happen for other reasons than overheating, like driving in a lot of road salt with too long time between braking hard.

Sometimes the brakes can be fixed by running a bedding procedure. Find a deserted road, and repeat braking from around 100 km/h - 20 km/h, 8-10 times with brisk acceleration in between. Then keep driving for about 10 minutes without touching the brakes. Do not stop during the procedure. Notice that some people get nauseous doing this, and make sure no cars are following close behind you.
Thx mate, lot's of good tips there. The last one could be spot on since my car was driven mostly by a girl, and on long commutes in Norway = lot's of salt and never using the brakes like they are intended to be used. I actually tried the "glazed-discs-bed-in-process" on my way home but I had no "progress" like those other times I did this with new brakes needing bedding in. The pedal never got softer (than it was) and the bite was the same after 10 braking attempts from 100kmh to 20 @ 80% force/capasity. There was no smell from the brakes during this, and no grey contact area on the discs afterwards. I just had lunch and the only thing that happened was me being semi-sick like I had been o a roller coaster for hours.

Quote:
Originally Posted by No one View Post
Brake fluid is supposed to be changed every 2 years. The first time I wondered they told me it was all right to keep it for the third year. This time (the fifth year) they threatened me brake fluid warning was about to pop up and failed to explain why 3 years had been all right previously (did those reset it regarding the warning?).
Thx, yeah I have to get it changed asap and ask the mechanic to get ALL old fluid out and also use a rubber mallet to get ALL trapped air out!

Every second year is correct. Here in Norway the normal routine is 4 years from new and the every second year. For somee reason I find that idiotic but I can understand that as otger components on the car gets older than 4 years things tend to deteriate faster and it's wise to get it replaced more often...

Another Thing I forgot to mention is that when I brake and the car is decelerating there a juddering sensation, like there is uneven wear to the pads or warped discs... I really hope not the last is not the case. Theres plenty of material left on the discs and I suppose a work can cut some material off from them to get them evened out. But if the discs are warped or uneven wouldn't there be a kind of vibration too when applying the brakes one where feel it in the steering??
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      09-16-2018, 08:27 PM   #6
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Quote:
Originally Posted by Estoril Blue 116d View Post
Another Thing I forgot to mention is that when I brake and the car is decelerating there a juddering sensation, like there is uneven wear to the pads or warped discs... I really hope not the last is not the case. Theres plenty of material left on the discs and I suppose a work can cut some material off from them to get them evened out. But if the discs are warped or uneven wouldn't there be a kind of vibration too when applying the brakes one where feel it in the steering??
Warped discs is quite uncommon, but sometimes the brake pad material get deposited unevenly onto the discs. Usually the bedding procedure will fix that. If the rear discs are uneven, you will not feel it in the steering.
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      09-17-2018, 02:21 AM   #7
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Quote:
Originally Posted by ovekvam View Post
Warped discs is quite uncommon, but sometimes the brake pad material get deposited unevenly onto the discs. Usually the bedding procedure will fix that. If the rear discs are uneven, you will not feel it in the steering.
True that, I have never experienced warped discs with my own cars but Iíve seen it on some customerís cars
The rear pad are guite down and I will change them if the new fluid/air out isnít solving the problem...
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