i have a xantia and the brake pedal pulses badly and has very little stopping power, but the fault is not all the time? i have no loss of fluid and the pads are new allround .the car passed an mot three weeks ago, and i have no abs light on. some times if you brake the pedal feels fine but after 2 or 3 uses it goes solid and very poor stopping just like a normal car when the servo fails would be it also pulses like a b s is working but it does this under normal braking have run out of ideas and am ready to scrap it please help as i do like the car and its to good to scrap

kev a, December 2009

Get a new accumulator sphere.... check that the pump isn't 'ticking' like an alarm clock!

aviatar, October 2011

It is your ABS activating.
Easy to prove, just remove the ABS fuse and take the car for a drive (dont worry, the brakes will still work, it's just the ABS that will be disabled). If the problem goes away, then it is your ABS that is faulty.
Probably one of the ABS reluctor rings is dirty, incorrectly fitted, loose, cracked, rusted or chipped.
Visually inspect them, it is often obvious which one is faulty. It should show up on a diagnostics live-data scan.
Remember to replace the fuse.

cheesy, December 2009