Brake pedal not fully pressing

[ljwjones]

Howdy!
First off I do have my car booked in for Tuesday but just hoping for a head start.

Basically early last week the stop/start on the 110 Airdream DSport Plus stopped working. I thought nothing of it until on Thursday as i was pulling off the motorway the brakes stop functioning fully! I can press the pedal down but it only goes about half way, and does not provide full stopping power.
If I sit still and press the pedal the brakes build up pressure like the engine is off, as soon as I move a bit this pressure goes but can still only press the pedal half way.

Thinking this braking issue and the stop/start issue are linked. Anyone any ideas? Also if so any idea on a rough cost to repair?

Thanks in advance!

[DaveB]

Possibly a brake servo fault?

To test it, press the pedal several times with the engine off. You should hear a hiss the first few times you press it. Keep your foot hard on the pedal & start the engine; the pedal should go down as vacuum builds up in the servo.

Edit:

It's worth checking that the vacuum hose into the servo is firmly attached & not leaking.

I've just noticed that your car is a diesel - another possible cause of your problem is failure of the vacuum pump.

Just to reassure you, if the problem is in the servo system you have got full stopping power - you've just got to press a lot harder on the pedal.