Mercedes b class sport bouncy brake pedal

[cjrboat]

hi all i have a b class and been back to the dealer several times and getting fobbed off all the time and now the warranty is now out ,
the problem i have is when braking my brake pedal bounces up and down as if a disc is buckled but i have changed the 2 front discs and the problem still their, at wits end dealer is not interested at all i hope someone can help as i feel like swapping my car but why should i help please i also get a vibration at 60 mph and over all new tyres on all round as well regards bazzzzzzzz as it has only got 34 000 miles on

 

[Burnerman]

Baz, your problems could be coming from the front or the rear discs - both need to be checked.
The simplest way is to use a dial indicator if you have one - disc run out must be absolutely minimal.
Sometimes if the hubs aren't rust free before new discs are fitted, this problem occurs.
Recommendations can be to rotate the new discs 90 degrees and try again but I've never found that necessary.
John

 

[cjrboat]

thanks burnerman it was the rear brake disks they where full of potholes thanks again bazzzz