Brake pedal intermittent pulsing (abs feel)

[Leonard73]

Hi,I’m new to the Citroen world ,just bought a 2000 xsara Picasso 1.6 8v petrol with 41,000 miles on it ,anyway I first noticed the brake pedal had a lot of travel but then worked fine if I pressed it again (like pumping brakes ) also occasionaly I get the feeling of abs pulsing and can here a noise (sounds like from engine bay ,any pointers would be greatly appreciated ,I’m changing front discs and pads and fluid this weekend .

[Sloppysod]

Hi,I’m new to the Citroen world ,just bought a 2000 xsara Picasso 1.6 8v petrol with 41,000 miles on it ,anyway I first noticed the brake pedal had a lot of travel but then worked fine if I pressed it again (like pumping brakes ) also occasionaly I get the feeling of abs pulsing and can here a noise (sounds like from engine bay ,any pointers would be greatly appreciated, I’m changing front discs and pads and fluid this weekend .

I would see if this issue resolves itself, as 41,000miles on a 24 year old car is very low.
There is a possibility that what you had planned to do (as its Monday now) is all it needs.

[shtu]

(I'm assuming this is a C4 based car)

While you have the discs off undo the ABS sensors, and be sure that the surface they mount to is clean and rust free. This might need scraping and chipping at to remove thoroughly.

The area underneath the sensor rusts, and pushes the sensor away fron the magnetic ring. This picture gives you an idea of what it looks like,



Also have a look at the magnetic surface, be sure there's no missing bits.

[wheeler]

The Xsara Picasso has traditional type sensors,
A common cause of this issue is the pickup on the front CV joints rust & break meaning the pickup can slip on the joint & cause erratic readings. This in turn can make the ABS activate as it thinks the wheel has locked up.

[Gibbo2286]

This has for me been the most common ABS fault on my Citroens.