Mercedes ML270 CDI 2004 Hard brakes

[Mummylyn]

I have a problem with my brakes there does not seem to be any hissing coming from the brakes when used in idle. The brake pedal in neutral is very very hard to push? I changed my brake pads 4 months ago and have not had any problems with the brakes until now? I purchased the car without a manual. Could anyone shed any light on why my brake pedal has all of a sudden gone hard to push where I have to literally stand up on the pedal to stop the car and even then it takes a while to stop??? No grinding or vibration when I do push the brake pedal down??

 

[Frosty149]

Morning Lyn,
Sounds like the servo and possibly master cylinder are at fault, whilst I am no expert here, this fault needs a prompt bit of attention (obviously!).
I'm sure a more technical bit of assistance from here, will be forthcoming soon.

 

[LostKiwi]

As yours is a diesel it has a vacuum pump which provides vacuum to the brake servo.
You could have a pump failure, servo failure or the hose linking them may have a leak (but I'd expect a hissing noise under the bonnet).

 

[John Laidlaw]

Has the car been sitting for a while?