ABS dangerous?

[MartinM3UKL]

Sirs, I have had a VW Fox Urban for about a year, it is the first car that I have ever owned with anti-lock brakes. I became aware that the brakes juddered when applied when going over a rough surface or ramp, and the car would stop over a longer distance than intended. Last week, on a dry road I narrowly missed another car coming towards me as it pulled out of a side road in my direction, after just going over a speed hump at 15-20 mph I applied the brakes sharply only to find my car still travelling towards the other vehicle at the same speed with the brakes juddering, luckily the other driver avoided a potential accident by veering sharply. Had it been a child run out in front of me in the same place I would have hit them despite having applied the brakes. I have consulted the car handbook and it tells you NOT to ‘pump’ the brakes, not that you would have time or reactive thinking to do so in such circumstances, this is very concerning to me now.

My questions are:

1. Is it normal for anti-lock brakes to be so dangerously ineffective in such circumstances?.
2. If so, Are the police and insurance companies aware of this?.
3. Have I the option of having such a system removed, especially considering the worsening condition of Britain's pot-holed roads and an increasing number of speed humps?.

Many thanks

[Airjer_]

I would bet that there is a problem with the brakes that you have not discovered yet. The anti-lock uses the brake system but the brake system does not need the anti-lock system to function. From what you described it sounds like you might have a condition known as overactive ABS. If it thinks one wheel is stopping faster than the rest than it will reduce braking force to that wheel. If it happens to be one of the front wheels than you just lost a lot of braking ability.

The other possibility is there is a mechanical problem with the brakes. Maybe one side has frozen up leaving a majority of work for the other side. It could be possible for the ABS to sense this and reduce braking force to the side that is working. The speed bumps come into play possible because the front suspension may need some help as well.

Worn shocks and struts are known to increase braking distance (increasing is bad). Overinflated tires can also contribute to increased braking distance.

You definitely have a problem until its figured out you would be better of taking the bus.

[ctwright]

Sounds more like to me you need to check your brake fluid, probably bleed the brake fluid. I'd also check your brake pads as well.

[MartinM3UKL]

Many thanks all for you prompt replies and erudite knowledge!.

I did fail to mention that the car was brand new from a year ago, and I've only done about 2900 miles in it, the term 'overactive ABS' will be the one I use when I take it back to the dealer. I will probably be met with the reply "they all do that" in which case I may take the matter up with the VW design boffins, failing that I shall take it to other organizations involved with the prevention of accidents.

Cheers,

Martin

[denisond3]

With ABS brakes you should be stopping just about as fast as if you had a -pre-ABS car on a good dry surface and almost-but-not-quite locked up all 4 wheels. Except the shuddering takes getting used to. I used to get rental cars with ABS brakes on business trips - and I would always check them out on a back road or industrial parking lot. Uniformly they would stop me really fast, and in a straight line. With shuddering. (My daily drivers are older and dont have ABS brakes. They were my 'comparison').
Be sure to get the dealership to give you some piece of paper with their writing on it - so they know there will be a paper trail in the event it doesnt get fixed & you run into something.
By the way... I have a '35 Bentley 3.5 liter coupe: They came standard with power assisted cable/rod brakes and an antiskid feature for the front wheels. The car is in rough shape, but the anti-skid feature still works; and works equally well on wet or dry pavement, gravel, even wet grass. I can lock the rear wheels, but the front wheels will still be turnining, keeping the car steerable.