Overactive ABS

[ruari]

Often when I brake, as I approach a standstill I feel a little twitch in the brake pedal as if the ABS has kicked in just for a single pulse. It's not so far caused a problem and the ABS light isn't flagging anything up, but I just wondered if there's such a thing as an overactive ABS, if it's a regular issue and if there's a straightforward solution? I've not so far had to brake hard on a poor surface so I'm not sure quite how well the system works at the best of times.. might have to do a little test at some point!

[Way2go]

I would imagine that your problem is more likely to something like a high spot or warp on your disc(s) that you are feeling through the hydraulics rather than the ABS.

AFAIK the ABS light only sequences as a test when the ignition is switched on and does not illuminate when the ABS operates - and why would it, you don't want the instrument panel attracting your attention away while you are trying to see/steer around an obstacle.

The BX also does not give a pronounced ratchety feedback to the brake pedal like on a Ford when it is operating, it is a much softer pedal effect.

[Vanny]

On my car the ABS on mine has always been 'overactive' as you put it, it will often start hammering if your breaking when going onto or off of a long flat speed bump at low speed. In fact its not unusual for it to trigger in that 10 to 20mph region where ABS is a bit useless. I don't know if this is normal behaviour or not, but it's the reason i have an isolator fitted to knock the ABS OFF when on track!

[bx_pallas]

I had the exact same problem. A bad sensor cable (the moving part in the wheel arch) confused the ABS, and caused the rattling. When it occured while braking I suddenly had to press the pedal harder because only one of the front brakes was actually braking at this moment(!!). After replacing the faulty sensor, the symptom was gone.

Test the sensors one by one by connecting them to a simple headphone (or to the radio aux) while driving. Sensors with a good cable make a clean tone, bad sensors make cracks and interruptions at bumps or at certain steering angles...



In the meantime, I highly recommend pulling the ABS Fuse F14 (1st from right). This disables the ABS completely (yellow light will stay on all the time) and you can rely on a safe 4-wheel-braking and no more dangerous ABS-overactivity.

[ruari]

Very interesting, thanks for that. I'll have a play with the sensors. I'm tempted just to do without the ABS entirely really, I think I trust my own footwork more than a 21 year old bit of gadgetry

[Defender110]

I'm tempted just to do without the ABS entirely really, I think I trust my own footwork more than a 21 year old bit of gadgetry

I've done this for the last 3 years and although it should be a problem at MOT time in reality it never has (bulb disconnected).

[Dollywobbler]

That's the worry. Rules are tightening up on ABS and the MOT, but at the end of the day, it's down to your tester.

Personally, I think ABS is well worth having on a BX due to the power of the braking system. Yes, I can cadence brake with the best of them (and it saved my skin when I almost smashed the Mk1 estate into a van once) but ABS has genuine benefits.

I don't get any ABS-kicking-in vibes on mine, unless there really is a traction issue.

[Way2go]

Personally, I think ABS is well worth having on a BX due to the power of the braking system. Yes, I can cadence brake with the best of them (and it saved my skin when I almost smashed the Mk1 estate into a van once) but ABS has genuine benefits.

I agree, it was one of the most significant technical motoring advances of the 20th century - being able to brake and steer simultaneously! Also when used in an emergency it does seem to shorten the stopping distance as road friction is maintained. Personally it would always be on my feature list when choosing a car.

[MULLEY]

Always handy if you get caught unawares, you then don't have to rely on too much skill which by the time you realise you need, its too late as you slam into something because the car has skidded & you cant change the direction of where you're heading. Any ABS is a blessing imho, i don't have it fitted to the TXD & i have locked up a few times in greasy conditions & its not a nice feeling

[Jaba]

I love ABS so much that I retro fitted it to my Hurricane. I am sure it has saved me quite a few prangs.

[Tim Leech]

Friend of mine had a similar issue on a Rover 416 a few years ago, it was a cracked reluctor ring on one drive shaft in the end.