Help! 306 ABS not working after MOT? - pug will
Hi,

My girlfriend slid my P-reg 306 TDS into the back of someone on a wet A23 on Saturday. I wasn't in the car, but the way she describes it sounds like the ABS wasn't working - she slid for a good 20-30m and couldn't steer at all.

The car was MOTd about 3 weeks ago and failed on the rear bushes so I had them replaced along with the rear shocks. It just occurred to me - could they have failed to connect the ABS back up properly when they did the repair? Would a warning light not have lit up if they had? What do I need to check for?

It looks like my car could be written off, I'm really gutted.

Thanks in advance,

Will
Help! 306 ABS not working after MOT? - Altea Ego
Does your ABS warning light come on when you turn on, and then go out? Did it do this before the MOT?
Do you have ABS on this car?

Is your girlfriend lying? is her driving rubbish - ABS wont stop her crashing.
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TourVanMan TM < Ex RF >
Help! 306 ABS not working after MOT? - pug will
Hello,

Thanks for the reply. I don't know about the light but it certainly did work before as it has got me out of a tricky situation once or twice.

Her driving isn't rubbish, this was her first crash in 13 years.

Help! 306 ABS not working after MOT? - Adam {P}
What about now - does the light come on and then go off?
Help! 306 ABS not working after MOT? - pug will
What about now - does the light come on and then
go off?


It's in a pound about 10 miles away so I can't answer that straight away - if not, what would it indicate?

I guess I'm wondering whether it's possible that the garage could have caused this problem by working on the rear suspension?
Help! 306 ABS not working after MOT? - Adam {P}
If it doesn't come on then it either means:

a) The car doesn't have ABS (which it does you think)

b) The ABS is knackered. I would have thought that if there was a problem it would light up and stay on but if the car has ABS then the light must come on.


There's a c) The ABS bulb has gone.
Help! 306 ABS not working after MOT? - pug will
Hi,

Well there wasn't a warning light showing, so it could be c) I guess.

Would the rear wheel sensors need to be disconnected for the repair that the garage did?
Help! 306 ABS not working after MOT? - Adam {P}
Pass.

Someone will know much more than me though and will be along soon.
Help! 306 ABS not working after MOT? - pug will
Cheers - thanks for your replies.
Help! 306 ABS not working after MOT? - Dynamic Dave
Would a warning light not have lit up if they had?


Should have done. That's what the light is for - to indicate a fault in the system.

edit, replied before seeing your duplicate post in discussion - which I've now removed, and moved all the replies here - DD
Help! 306 ABS not working after MOT? - RichardW
It's possible to change the rear subframe mounts in a 306 / ZX without disconnecting the ABS sensors - I've done it. Your garage might have done, but this should immediately have shown up after the repair as the light staying on.

Most people react in 1 of 2 ways when emergency braking with ABS:

1. Clamp on the anchors and activate the ABS, ignore the fact they can steer and crash into what ever they could have avoided.
2. Clamp on the anchors and activate the ABS, immediately followed by letting the brakes off as they 'feel funny' as the ABS bangs away. They then hit whatever they could have avoided.

It will be difficult to prove if the ABS was working at the time or not - unless the Police attended and have taken records of the skid marks (or lack of them if ABS was in operation).
--
RichardW

Is it illogical? It must be Citroen....
Help! 306 ABS not working after MOT? - pug will
Hi Richard,

Thanks for the reply. My girlfriend doesn't remember them feeling funny (i.e. vibrating), but she definately tried to steer away and the car continued sliding in a straight line. The police did attend but didn't take any record of skid marks I think.

Cheers,

Will
Help! 306 ABS not working after MOT? - Altea Ego
Will

you need to know how the warning light operates.

When you turn on the car, the abs warning light comes on to tell you a: the bulb is working, b: the system is being checked. It then goes out to say everything is ok.

IF there is a fault, the light will either a: not go off after the turn on test, b: come on at any time during driving to indicate a problem

How did this light behave prior to work on car, and after the work on the car. If the garage broke the ABS the warning light would be on. ( if it passes the bulb check that is


Not being funny, but most girls (and a lot of blokes) in a panic situation wouldnt know the difference between ABS working and thier lipstick
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TourVanMan TM < Ex RF >
Help! 306 ABS not working after MOT? - Collos25
Driving to fast to close I'll wager .
Help! 306 ABS not working after MOT? - yorkiebar
Assuming the car has got ABS.

The light would have worked correctly for it to pass the mot test.

If work had been done and abs system touched and not reconnected etc the light would have stayed on.

Either the car has not got abs; so no system warning light would be activated, or the the car has abs and the light was working correctly so the abs system should have been, or the light was working incorrctly (staying on) and was being ignored. If the latter it should have faile dthe mot unless it was like that since the repair, when the car shoud have been driven carefully and returned to the garage for investigation.

Sorry, but it sounds like too fast for conditions etc!
Help! 306 ABS not working after MOT? - Adam {P}
Hi Will,

I don't want to sound patronising (but I'm going to because I don't get the chance very often) but are you sure you're thinking of ABS? What did it actually do to get you out of trouble those few times?

Adam
Help! 306 ABS not working after MOT? - pug will
Hi Will,

What did it actually do to get
you out of trouble those few times?


Whilst half-asleep one morning I saw stationary traffic too late and jammed the brakes on. When it became clear I wasn't going to stop in time I turned the wheel and, whilst skidding, managed to steer around the car infront and in to a lay-by.
Help! 306 ABS not working after MOT? - Adam {P}
You shoudln't have skidded at all if you'd had ABS.

I don't and I've skidded a few times (mostly my fault) and turning the wheel sometimes turns the car, other times doesn't. It depends on what's caused the skid and the surface of the road. DId the pedal start pulsing hard? (If you can remember).
Help! 306 ABS not working after MOT? - Bill Payer
When it became clear I wasn't going
to stop in time I turned the wheel and, whilst skidding,
managed to steer around the car infront and in to a
lay-by.

Hmm - if that's what you're basing your belief that the car had ABS on, I'm not so sure. It's pretty obvious when it kicks in.

I found a year by year chronology of the 306 and that seems to indicate (although obviously this isn't incontrovertible) that ABD wasn?t fitted as standard on your car (although maybe ? but unlikely it was fitted as an option). It seems to have been fairly widely fitted as standard on 306?s from Feb 98.
parkers.mirror.co.uk/cars/reviews/Review.aspx?model=651&page=5 (there's no www in the url - just http then park...)
Help! 306 ABS not working after MOT? - Simon
After reading your posts it appears to me that you are trying to pin the blame for your girlfriends crash on the fact that a garage did some work on your car recently. I personally think the garage are highly unlikely to have done something to your car that has in anyway contributed to the accident, you are just looking for a different scapegoat, when the only person who was obviously at fault was your girlfriend. Sorry if that sounds harsh, but whether your car has ABS or not, if she was both concentrating on what she was doing and the correct stopping distance away from the vehicle in front the should wouldn't have wellied the vehicle in front up the backside.

If the ABS was faulty then the warning lamp would have been illuminated on the dashboard when driving along, if it had been the it would have been noted by either you or your girlfriend at some point. Trying to clutch at straws by looking for a way to blame the garage is a waste of time. You'll only beat yourself up over it and will never prove anything anyway. And don't forget that ABS isn't some magical driving device that means you always avoid the crash, it is only there to aid and supplement the skills of the person behind the wheel.
Help! 306 ABS not working after MOT? - autumnboy
Are you sure you've got ABS, cause if you did.

You would not skid wet or dry and you would feel a pulsating in the pedal and steering wheel when the ABS is working.

If as you say your girlfriend skidded some 20/30 mtrs and you skidded around one near miss on one morning, it sounds if you dont have ABS. Especially as you've not noticed any warning lights showing the system charging or not, when you switch the ignition on.


Help! 306 ABS not working after MOT? - autumnboy
As regards to the MOT testing, its only any good at the time of the test not sometime after.
Help! 306 ABS not working after MOT? - rtj70
Don't forget ABS lengthens stopping distance (slightly) but because you can steer helps avoid accidents.

Maximum breaking force only available when wheels locked and your are skidding - max friction. But you cannot steer. And skidding when it's wet means lengthy stopping times and why you need to significantly increase distance between cars.
Help! 306 ABS not working after MOT? - Statistical outlier
Sorry rtj70, but that's wrong, at least in part.

Maximum friction is the point right before a slide starts. The coefficient of static friction is always higher than the coefficient of sliding friction. Microscopic variations in the two surfaces lock into each other when there is no relative movement, providing more grip. That's why older trains used to have play in the couplings - so that each carriage was jerked forward, breaking the 'stiction', and that's why air suspension systems suffer at low speeds. Stiction is a difficult engineering problem to overcome.

Whether a car with ABS takes longer to stop than one without I don't know. Perhaps, but I would think only because the system is set overly cautiously, but I'd be surprised. If a car has 'dynamic brake distribution thingy', or whatever it's called, I'd expect it to stop more quickly, as I've not yet seen a car with four brake pedals. Or a driver with four feet. Although it would be hte logical progression from heel and toeing.

Gord.
Help! 306 ABS not working after MOT? - Number_Cruncher
Gordon,

Tyre to road friction is a bit more complex than that.

On a dry road, you get maximum longitudinal force when the tyre is slipping by about 20% - i.e. you have gone way beyond static friction before you get to the friction peak. On a wet road, this percentage is lower, but not zero.

Part of the reason behind this is that the rubber conforms to the road surface, and doesn't behave in a classical solid friction manner. For example, F = mu x N doesn't really apply, because for rubber, there *is* an area dependance.

The difficulty faced by ABS is that it can't tell the true speed of the vehicle (because all systems rely on measuring wheel speed, which, depending on slip conditions can be less than accurate!)

So, the ABS has to attack the problem pragmatically, by cycling the brake pressure up until it senses a rapid deceleration of the wheel, and then releasing until it senses the wheel is rotating again. By doing this cycle rapidly, the wheel passes through the region of maximum friction once per cycle. i.e., the ABS homes in on the maximum friction area of the slip curve, but can't actually position itself there.

If an ABS system is in cycling mode on all four wheels, then you are getting the equivalent of the dynamic brake distribution, via the iterative technique of the ABS controller (assuming the ABS controller does control all 4 wheels independantly, and isn't one of the older "select low" systems).

Among the problems with ABS is that people tend not to prod the brake pedal hard enough, and get worried when the ABS starts cycling, and let off.

Incidentally, with rail wheels, you are unlikely to see a friction peak,the characteristic is much more insidious, which is one of the (many!) reasons why wheel slip protection is difficult to implement on trains, and that leaves on the line are still problematic.

Number_Cruncher
Help! 306 ABS not working after MOT? - yorkiebar
All very informative, but I still think we are at the point of identifying if the car has got abs or not and if so was the light indicating it was ok or faulty.
Help! 306 ABS not working after MOT? - bell boy
yawn-----------------

www.highwaycode.gov.uk/09.htm

think this answers any question to be honest----------
ive heard it all before -----------------
Help! 306 ABS not working after MOT? - pug will
Thanks for all the replies. I'm not claiming that it wasn't my girlfriend's fault - it was.

That said, I was under the impression that "for a majority of drivers, in most conditions, in typical states of alertness, ABS will reduce their chances of crashing, and/or the severity of impact." (en.wikipedia.org/wiki/Anti-lock_brakes ).

Therefore, if my car has got ABS, I think a bit of investigation can't hurt.
Help! 306 ABS not working after MOT? - Adam {P}
I don't think it has ABS mate.
Help! 306 ABS not working after MOT? - adverse camber
Dont believe everything you read in wikipidia - half of it is tosh. Ive seen people alter it then quote it in arguments.
Help! 306 ABS not working after MOT? - jc2
Only half????
Help! 306 ABS not working after MOT? - SteVee
The work was on the rear of the car - and it's the front brakes that contribute the (vast) majority of the braking effort, and we can conclude that the front brakes worked just fine.
If the car had ABS then it would either have worked on the front wheels, or displayed a fault light on the dashboard - at least after the MoT work was done.
The idea that the bulb was OK during the MoT and blew immediately after the bushes were replaced is a very long shot.
I'd guess that the car doesn't have ABS.

I hope your girlfriend's OK after the crash.
Help! 306 ABS not working after MOT? - LeighB
I have rear ended someone in a 306 with ABS (entirely my fault I hasten to add!) When I hit the brake on a slightly damp road, but too close to the car in front, I was very aware of the pedal throbbing as the ABS did its best to help. The ability to steer clear would not have made any difference in this situation.
Given what has been said above, I suppose it is just possible that without ABS I might just have stopped fractionally sooner?
It sounds as if the car in question was not ABS equipped.
Help! 306 ABS not working after MOT? - Statistical outlier
Interesting, I stand corrected. :-)
Help! 306 ABS not working after MOT? - jc2
An ABS equipped car will outbrake a non-ABS car in the hands of most drivers-you would have to be very,very,very expert to beat the system.
Help! 306 ABS not working after MOT? - yorkiebar
probably very technically correct but I have to disagree.

In most lesser experienced drivers hands (or feet?) they will release the brake pedal when the abs is activated and even possibly panic causing the braking to take longer than under conventional system.

Most people with abs have never activated the system and do not know what to expect or experience and as such abs imo is over rated and possibly more likely to contribute to an accident. these same people treat it a s a magic stopping aid and drive faster and closer than they would if they didnt have it.

I do agree that experienced people with it are probably safer with it though. perhaps driver education is needed.

I think this is likely to be contested, and discussed, but its my opinion after talking to lots of people about abs.
 

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