oscaar12

I have 40,000 miles and the brake pedal slowly goes down when the pedal is held on for a long time on a hill or such. The pedal also seems soft after driving a distance.. The brakes were bleed at the dealer 20,000 miles ago.It stops fine. The dealer stated that they have never changed a master cylinder.??? Other than this issue the car is flawless

bop11

More likely the brake booster if you are not losing fluid.

ESBenz11

Is that not a brake assist feature?

oscaar12

The dealer says it is normal

bop11

Test drive a used one on the lot, if it is "Normal"

rmfnla

Sounds like classic "air in the system" symptoms to me...

MKenM

I have 65K on mine and it also stops fine I don't have the problem you are stating unless I tried to stand on the brake pedal while standing still. Brake assist only comes into play in a panic stop.

fabbrisd1

At 20K intervals the brake fluid is to be flushed and replaced - frake this 20K "bleeding" unless that was a misinterpretation.

MKenM

Theoretically if you want to get the fluid out of the brake line you do need to "bleed" them.

NYCGLK

Originals?
I have 54k on mine. Bought new rotors and pads because sensor said so. Took the wheel off and saw probably 40% of pads left. Replaced the sensor with new one. Now I have a set of MB rotors and pads laying around.

MKenM

My mechanic says I still have about another 10K left on my pads. I'm not necessarily a slow driver but I have found what helps me with the brakes is manually down shifting as I am coming to a stop. I do it almost all the time. I let the trans do some of the stopping work.

NYCGLK

I've done it a few times as well and still do it on long downhills. But I found just keeping in S produces similar amount of engine braking where I often barely touch the brakes.