Xantia s2 ABS problems...

[Lankytim]

Hi Shitists,

 

My 2001 HDi has an issue with the ABS. As the car is slowing down the ABS cuts in at low speed, about 2-3 MPH, causing the pedal to pulsate and braking to be impaired. I thought it could be a dirty O/S/F sensor and ring as I had the hub apart recently and the whole lot ended up covered in grease when I replaced the CV gaiter. I cleaned the whole lot up tonight with WD40 and a scrubbing brush but the fault persists.

 

Any ideas on what the problem could be?

 

Tim

[ruffgeezer]

Broken ring on one of the front drive shafts, the gap expands and causes the abs to misread.

 

Like this:

 

Replacement rings are available for about £35 but require heating up to fit, try http://www.reluctorrings.com/ for yours, we have used them on a Xantia like yours in the past to good effect.

[skattrd]

I'd double check the ABS rings for splits or missing teeth.

My Volvo did similar but at a higher speed when the ABS ring was split, as it sounds less severe it could be something small like a worn or missing tooth.

I disconnected the ABS until I got the ring replaced, unplugging a couple of sensors usually does it.

[Lankytim]

The ABS light isn't on so I was hoping it wouldn't be something like a broken ring. Will it be an MOT issue?

[skattrd]

That sounds expensive for ABS rings RG.

The Volvo ones I got off ebay cost £3 each.

 

ABS light doesn't always come on with a broken ring, as it is reading the wheel move.

[Lacquer Peel]

My Volvo 940 had a similar issue, it was down to utterly knackered rear pads.

[ruffgeezer]

The ABS light isn't on so I was hoping it wouldn't be something like a broken ring. Will it be an MOT issue?

 

It won't be, the sensor can't tell the ring is broken, only that the reading from it differs in speed to the others, hence the weird brake behaviour.

 

Skattrd: I may be misquoting that price, you are right a Xantia one is £2.50 on ebay!

[Lankytim]

Driven the Xantia and the problem is much less but still there. I'm wondering if the sensor was twatted by the ring when the bearing ate itself.

[Bren]

I had exactly the same problem with my xantia - somewhat frightening when you are approaching the rear of another vehicle!

 

When it manifested itself the abs light illuminated sometimes, but not all of the time.

 

Realising that it would fail the MOT (and possibly kill someone) it had a garage look at it - they confirmed it was indeed a duff sensor, not the ring.

[ruffgeezer]

It isn't going to go away Tim, the rings are the first and easiest thing to check, also make sure one of the CV boots hasn't lost it's clip as they tend to cover the rings too.

[Lankytim]

I have a spare sensor I can try out but in the mean time I'll give everything a thorough inspectiob. Dont the rear hubs have rings and sensors?

[Lankytim]

All fixed! I'd bolted a metal shield on under the sensor rather than on top, meaning the sensor was a fraction too far away from the ring. Doh!

[tooSavvy]

All fixed! I'd bolted a metal shield on under the sensor rather than on top, meaning the sensor was a fraction too far away from the ring. Doh!

 

I read that some new sensors come with a bit of card stuck to the tip - presets the gap & simply rips away when you set off.

 

tooSavvy