Scary Moment - Dave Etchells
Any advice or clues?

Coming home from work this morning, as I approached a set of lights under braking I passed over a ridge in the road - it has always been there - probably as the brakes had just started to bite. Travelling no more than 25 - 30 and slowing, the whole car bounced and as it settled back down I had the impression the brakes had failed. Naturally as I was approaching a car in front - not a Toyota - I had to brake a lot harder than I would normally do. The brakes then started to make a clicking noise which I assume was the ABS kicking in. Would the temporary loss of traction, assuming both wheels lost contact with the road surface - albeit very briefly - be enough to trigger the ABS?

The car is a 2001 Mondeo, just having covered 1000 miles and up to now problems free - mechanically that is.
Re: Scary Moment - Dave Etchells
ps. It was not a speed bump, the lights are on a single carriageway B road
Re: Scary Moment - David Woollard
Dave,

Is this the first time you think you have experienced ABS in operation?

If so go out on your own to a deserted road with miles of visibility and no traffic (easy to find here in the Fens). Make sure all is secure in the car and boot space. Get up to 40/50 mph a few times and slam on the brakes. Just leave the pedal on the floor 'till you stop each time and get used to the feeling.

I advise every owner (customers of mine) to practice with ABS as the juddering/vibration can be very harsh. Sometimes it seems as if the wheels are going to fall off.

On my Xantia pulling up into a gravel layby when the young kids need a pee will kick in the ABS.


David
Re: Scary Moment - Ash Phillips
Does the Xantia pulse the pedal like other cars? I hammered the brakes on ours (VSX with Hydractive II) and felt nothing. I thought it might be because the Xantia had plenty of high pressure as normal, whereas an "ordinary" car would have to have some kind of extra pump kick in which is what causes the pulsing. Or is it just bust :o(.

Ash.
Xantia ABS. - David Woollard
Ash,

You should feel the gripping/releasing effect through the whole car and also the brake pedal seems to go away from you in a slightly alarming manner.

Do you have the ABS lamp on all the time, does it come on with the ign or has the bulb been removed (very common)?

The tyre/roadgrip on a Xantia is very good so looking for a wheel lockup to prove the ABS isn't working can take more violence than many owners are prepared to throw at their cars.

David
Re: Xantia ABS. - Ash Phillips
David,

The ABS lamp lights at ignition then goes out so I'm assuming we do have ABS. I think I must not have pressed the pedal hard enough to bring the ABS into play - you really must have to be very brutal.

The only time I deliberately tried to get it to work was in the supermarket car park on a couple of inches of fresh snow last winter to see for myself whether it is actually a hinderance in such conditions like the experts tell us. I remember thinking the brakes felt unusually ineffective, but I can't say I remember the pedal falling away or feeling any grabbing/releasing. Got me intrigued now so I think I'll try it on a gravel or loose-surfaced car park so I can lock a wheel up easily without too much drama. Wouldn't surprise me if it wasn't working, seems Xantias are good at having bits that stop working (the wife is on first name terms with most of the service department!!) and yet she's just chosen a C5 as her new co. car!!!.

Ash.
Re: Scary Moment - John Slaughter
David

Chap I used to work with didn't realise how harsh and noisy ABS can sound and feel. Following activation of the ABS one winter he took the car (Citroen BX) into the dealers thinking it had a brake fault. They demonstrated the ABS effect and convinced him it was fine. He was one who never read the manual and wasn't even aware the car had ABS! There really is no hope for some people.

As you say not uncommon to get it working while stopping on gravel, and well worth testing its effects before it comes on for real. I always think a frosty road at lowish speeds is an ideal time to demonstrate the ABS.

Regards
Re: Scary Moment - Michael
Good advice David. You need to become used to the feel of the pedal and realise that ABS does not necessarily stop the car any sooner but it gives you the opportuninty to steer the car while under full braking pressure. It is not something that comes naturally and practice is vital. I always take advantage of the winter months to practice in a local car park that, when empty and covered in snow or ice, is ideal for low speed (10-20mph) practice.
Re: Scary Moment - Robert Harvey
Dave,

Yes, this would be enough to trigger the ABS. Other favourites are braking whilst crossing wet leaves, wet manhole covers or sand/gravel.

I agree with the suggestion of testing the ABS out to get the feel, but be careful where you do it.

Robert
Re: Scary Moment - Chris
I've heard this "pulling away from your foot" feeling is one of the reasons why they put brake assist in cars - people tend to lift off in a panic, thinking the brakes are defective. Then, the car in front WAS a Toyota.

Chris