bobbybigballs

hello, ive just bought myself a 2000 c43 amg, loverly car but I have now got a problem with my brakes.
most of the time when I just gently press the brake pedal down. it travels abit more than it should. then the brakes suddenly come on and throw me through the windscreen!!!!!! its very annoying...
there is a hiss from under the pedals and I get a headache.
ive changed the brake light switch with genuine.. and its still doing it..
has anyone had this before, any common faults. what do you think people...

Sulaco

2000 C43! Very rare.

Maybe a vacuum leak related to master cylinder? Sorry, I'm not much help. My brakes have been perfect.

bobbybigballs

sometimes it doesn't do it but I guess it could be a leak. its got brake assist and it feels like that cutting in??

they are rare are they, its the first ive ever seen...

gtrecordings

I need a master cylinder as well for my 2007 c280 4matic. I push the brakes and they are just soft, I let go and push again and they kick in a little stronger.

Where do you guys get your parts?

Eloquaint

I'm in the same boat with the terrible pedal feel. I've bled and bled them and it just isn't getting any firmer. Pedal feel is soft, vague, and it slowly sinks to the floor like a bad master cylinder. Is that a common problem on these cars?

raw1879

it could be the cailper sliders

gtrecordings

Thanks for the heads up!

bobbybigballs

BAS ESP light came on today, maybe this will help find out whats happening..
will let ya know..
also when the engine is off, I have a solid pedal, therefor cant be master cylinder...
how are yours with engine off..
talk soon

Eloquaint

I replaced my master cylinder with little to no effect. It doesn't continue to sink anymore but it still doesn't engage until nearly the full length of the pedal. I've bled and bled and bled with a pressure bleeder. I do know in my case that the front rotors are way out of spec, the no name pads in the front are hopeless and it feels like the rears are warped.

In your case with the grabiness you might want to check for a sticking caliper pistons. Check if your wheels feel hot to the touch after a drive and try coasting. Could be that or your pad compound in the front.

Honestly, not having driven any other C43s but having read other threads like this one I have to say it looks like a design flaw with the system and the solution is to change out the front calipers for a unit from a different model. Whether we want to do that for pedal feel alone is based on your income I suppose, though I feel like the delay in my obviously out of spec system wouldn't be safe in an emergency stop.

mbsickness

Sounds like your BAS is kicking in as it is designed to apply 100% braking force regardless of where the physical pedal is if it detects a panic situation. The BAS/ESP light is certainly pointing in that direction.

jarvis210

the pedal feel is due to design of front calipers, 210 55 208 55 and 202 43 all feel the same way and they all share the same brakes. only way i fixed mine was doing the slk 55 brake upgrade front and rear. my pedal feels perfect now and braking is very linear

bobbybigballs

finally got to the bottom of the problem...!
found that my servo had broken up inside allowing the 2nd stage to leak through under light braking, giving me the full 100% force..
found a 2nd hand one for £100! happy days.
cheers rob