Xantia brake problems.

[gpz900ra7]

Hiya folks, hopefully somebody on here will be able to shine some light on a problem I'm having with the brakes on my R plate Xantia 2.0 16v.

Every now and again the ABS Sensor warning light shows up on the dash and the ABS ceases to function, as it would do but, when the light is off, and I'm travelling at less than 10mph the brakes don't work at all, then start to pulse right at the last minute, ie: when coasting up to stopped traffic.

To say its scary is a major understatement .

I always thought the brakes were supposed to be really impressive on these cars but, for some reason on my car, they are pants, .

If there is anyone out there who can help, I'll be over the moon.

Thanks for taking the time to read this very long first post, I promise the following ones won't be as long,


Shaun.

[myglaren]

Greetings neighbour and welcome to the forum.

I can't offer much help here, only to say that your problem seems to be quite unusual.

I've had a GS, BX and an earlier Xantia without ABS and the brakes in all of them were way beyond criticism. My major gripe with my C5 is that it doesn't have proper Citroen brakes and had I known that before I bought it, I probably wouldn't have but opted for another Xantia instead.

On the other hand you are right to be concerned - I don't think I would be driving very far with that to wory about.

Have you bled the brakes? and how long have you had this problem?
Have you had the car very long?

[CitroJim]

Ahh yes, now there was a long thread about this a long while back.

Read it here.

I'd get the ABS checked out soonest by someone with a Lexia diagnostic machine; as Steve says, this is dangerous.

Do also bleed the brakes too although air tends to cause a short delay when the brakes are first applied.

My bet is a sensor just on the outer limits of it's tolerance; they do do some strange things when on the cusp of failing. On a Lexia you can see stationary wheels apparantly doing 50 odd km/h and when tested they are just a few ohms away from what they should be...

You can confirm it's definitely the ABS playing up by removing the ABS fuse just for a test.

[citronut]

if you press the pedel a bit harder do the bakes try to lock up, if this is the case i would say almost certainly air in the system, dose the regulater tick freakwently if so it is likely its dumped its gas into the system, then this would be the route of your problem

regards malcolm

[vince]

Also guys i learned of another scary brake fault on ABS models from the workshop manager of Citroen Manchester. He said that the ABS rings on the drive shaft can lose teeth as they corrode. When that happens you can get temporary brake failure as the ABS sensor cannot accurately read the wheel speed and so freaks out and does nothing. He recommends keeping them cleaned of rust every now and then. Its one of the first jobs i did

[gpz900ra7]

Cheers for all the responses guys.

I've never bled the brakes since I got the car but, I did have a full set of spheres fitted shortly after buying the car, and a complete flush and refill with fresh LHM fluid, saying that, that was about 4 years ago now.

The car has had a full set of discs and pads fitted recently, and the calipers are all free and well lubricated.

The ABS rings have no missing teeth, and were cleaned thoroughly when I done the discs and pads.

When the light is on, if I try and press the pedal with a bit more power the brakes will lock up no bother, again, a bit scary especially when its wet or slippy.

There isn't any delay between pressing the pedal and the brakes starting to work, its just the feeling of no control when pulling upto stopped cars when the ABS starts to pulse right at the last minute.

I'll give the thread highlighted in the post by citrojim a read, and see if that sheds any light on the problem.

Thanks again guys, and sorry for the huge post, even though I said I would try and keep them short...........er .


Shaun.

[Old-Guy]

Shaun

We've experienced the intermittent ABS warning on both Xantias in the family. Daughter had her's diagnosed by a local garage: "faulty OSF sensor". When I looked at it, it had obviously been changed before.

Subsequently, I had odd instances of the ABS warning light coming on (and no ABS) - holes in the road usually caused it to go out = bad connection.

Fixed both cars by removing the ABS ECU and carefully cleaning the contacts in the socket and on the ECU. No recurrence since.

If there's 'air' in the brake lines and the rear lines in particular were thoroughly bled (at least 250ml per side) when the spheres were changed, suspect a 'blown' sphere that's leaking gas into the hydraulic system.

I notice that you've had new discs fitted. I believe that Xantias are very sensitive to disc run-out. I've only done about 40 miles on new front discs and pads (so not bedded in yet), but I'm unhappy with the response - the brakes lack the instant 'bite' of the old setup. At the earliest opportunity I'm going to check the run-out on the front discs even though I cleaned the hubs fairly well - but perhaps not well enough?

I'll let you-all know what I find in due course.

Guy

[gpz900ra7]

Cheers for your input on this Guy.

The discs and pads have been fitted for quite a while now and do have some stopping power, its only the ABS malarky that is bugging me really.

I'm a bit strapped for the spending coupons at the minute so I'll have to wait until I can do some scrimping to get the car tested properly.

Just have to make sure to give the car in front a lot more breathing space until then .


Shaun.