Xantia VSX TD Brake judder.....

[citroenxm]

... quite badly too!! ONLY WHEN BRAKING!!!!

A 1996 N reg TD VSX Xantia with serious brake judder, like driving over a cattle grid but felt through the pedal when brakeing. ONLY when brakeing, not felt when lightly brakeing but under heavy brakeing it gets worse, and worse the more pressure applied.

Track rod ends and bottom ball joints checked and have NO PLAY in them, disks and pads were changed last year, but Im suspecting they could of got warped... Calipers not really holding on, though drivers was holding on a bit more then passenger, but NOT grabbing badly..

Im asking, Disks? Or drive shaft?

[Hell Razor5543]

Are the reluctor rings sound? Missing teeth would cause the ABS to get inaccurate rotational readings. Just a thought.

James

[Gibbo2286]

Reluctor rings also split and become loose on the shaft so you need to see if they are secure. If they're split a temporary fix is to clean off the muck and use locktite to hold them in place until you can do it properly.

[citroenxm]

Its NOT an electronicly caused judder its a mechanical one.. The car is an S1, and S1 ABS rings rarely rot like S2 ones. Anyway, looking tonight they were both in good order...

The judder is felt through the steering as well as the pedal.. I beleve any ABS release judders are only felt through the pedal...

Cheers

[Northern_Mike]

Previous experience with exactly the same problem on my old SX TD N plate Estate leads me to believe this is likely to be the discs warped, out of round, or not mounted quite true to the mating surface of the hub. I had new ones put on mine, they vibrated like hell after about 2000 miles. Removed them myself, cleaned the mating surface up properly, but them back on and they were ok.

[citroenxm]

Thanks mike, I am suspecting disks, they have been fitted for a few thousand miles and been fine. Ill look further.

They are NOT keen to spend If I can do it without, as they are getting rid in March/April this year.

WHEN I get time again, Ill go over and drop the disks off and check the surfaces.

I have posted this up just to see what other sugestions there might be.

I also suspected drive shaft, as being an early car it has the Thin Shafts, not the later massive thick shafts..

Cheers

[Mandrake]

If it was the ABS chattering you can rule it out dead easy - take the ABS fuse out and go for a test drive! My bet is it won't be the ABS though.

I'd agree with Mike, warped, out of round or incorrectly mounted discs... nothing much else can cause it really.

[isisalar]

I had exactly this problem on my n reg vsx td and it was Definitely Definitely caused by a sticking caliper piston. Judder from say 70 down to about 40. One of the jobs that didn't get done because of the death sentence.
Kind regards
Paul

[RichardW]

One of mine had a terrible brake judder, was convinced it was going to pull the wheel out of my hands one day! Eventually tracked it down to an out of round tyre - I wouldn't have believed it if you told me, but when I finally replaced the tyre it had a high spot on it, and the vibe was gone afterwards....