ABS question

duke of hazzard · 30-05-2007, 16:18

hi guys, just a quick question to all the octy owners who've had ABS kick in on them... when it kicks in i think that my brake pedal is actually rising an inch from where it was depressed to cause it to kick in. is this normal? having never had it before its quite disconserting to try emergency brake to have the pedal "lift off" of its own accord. whilst the abs is working it also appears to be impossible to depress the pedal further, is this supposed to be the case?

i hope someone understands me out there?

TeflonTom · 30-05-2007, 16:19

air trapped in the abs hydraulic unit???

duke of hazzard · 30-05-2007, 16:22

i dunno if anything is wrong or (and its probably this) im unfamiliar with the sensation of abs, i mean it stops like nobodys business anyway just curious inquirey.

micndiesel · 30-05-2007, 16:25

Never done a really hard break in my vrs but in a seat v5 i had a couple of years ago the abs used to make the pedal vibrate to calm you down, not sure if your car uses the same idea
when it did it the first time after thinking i dmamged something i looked it up in the manual and it explained it and the reason behind it etc

scotlad · 31-05-2007, 09:23

Quote:

Originally Posted by micndiesel

Never done a really hard break in my vrs but in a seat v5 i had a couple of years ago the abs used to make the pedal vibrate to calm you down, not sure if your car uses the same idea
when it did it the first time after thinking i dmamged something i looked it up in the manual and it explained it and the reason behind it etc

Calm you down? You're having a giraffe surely??? Its nothing to do with the modulation of the brakes going on and off and you're feeling it back through the pedal then???

Ha ha best laff i've had for ages!!!!!!!!!!!

mattbeef · 31-05-2007, 10:31

yea i didnt calm me down when i had it happen to me in the snow

ap0gee · 31-05-2007, 10:39

I seem to remember that when ABS first came out, it lead to an INCREASE in accidents, as people jammed on the brakes, felt the pedal vibrating, thought, "What the hell's that!?!", took their foot OFF the brake pedal, and drove merrily into whatever it was they were trying to avoid!

One of the few occasions where 'consumer education' might have actually been worthwhile (thinking about these off-road courses Land Rover drivers get offered when their new purchases won't ever go near a muddy field, let alone a pile of logs or a giant see-saw

)

KenONeill · 31-05-2007, 12:47

Having tested the ABS "properly" (with a genuine emergency on snow), you're going some to set it off in the first place, but it does kick back a touch when it does. It's a vibration from the valves cycling, not any form of "pedal pusher" though.

Morley · 31-05-2007, 13:59

Quote:

Originally Posted by mattbeef

yea i didnt calm me down when i had it happen to me in the snow

I think its probably better to turn off your abs in the snow, drive smothly and try to avoid the brakes altoghether.

Lady Elanore · 31-05-2007, 14:19

My ABS is always going off when braking firmly in the damp and driving over manhole covers or other slippery objects. I find it comforting that when one wheel has slipped slightly, in the space of a couple of feet the car has recognised this action and already correct the skidding wheel by modulating the bake line pressure to the offending wheel. It is a marvellous invention.

Most new cars (a la Octy II) have Brake Assist anyway, which detects panic breaking and applies maximum pressure almost instantaneously. I think it’s because many people when hitting the brakes (oh how often have most of us done this on a motorway when the car in front suddenly stops) hesitate slightly as to whether to give it 100% or not and by the time you realise that you should be giving it full effort its too late. The car recognises this dilemma and gives it 100%, after all it’s easier to lift off the brake than to reach full brake pressure. Some cars like Peugeots do this and put the hazard lights on too, once the brake pressure has reached 85% (or something like that)

With regard to ABS and snow. I remember driving my Clio 16V one Christmas day, up the A1 and a car pulled over and nearly hit me. I swerved towards the central reservation where there was still a lot of uncleared snow from the previous day. My Clio’s front offside wheel was dragged further into the snow as the extra drag of the snow pulled the steering in that direction. I was doing about 80mph and couldn’t fight the wheel turning. I slammed on the brakes and waited for the graunching metal sounds as I hit the barrier……………..nothing happened, except the lovely modulation of the brake pedal. The car had 2 wheels on bone dry tarmac, 2 wheels in deepish snow all at 80mph and it was slowing down in a straight line!!!! I regained control pulled over to the hard shoulder and clipped the plastic lip under the front spoiler back into place. BL00DY marvellous thing ABS.

TeflonTom · 31-05-2007, 17:44

Quote:

Originally Posted by Morley

I think its probably better to turn off your abs.

you cant! hth

unless you take the fuse out

mattbeef · 31-05-2007, 17:49

i though that they had got rid of the fuse trick??
Just for errrrr diagnostics what number fuse would it be?

TeflonTom · 31-05-2007, 17:53

andyrew · 31-05-2007, 23:06

Quote:

Originally Posted by Morley

I think its probably better to turn off your abs in the snow, drive smothly and try to avoid the brakes altoghether.

completely agree with that. when it snowed not so long ago, i just turned the traction control off and took it very carefully. just as i turned the corner into work the front lost all traction so i yanked up the hand brake in a sort of panic but it kicked out to the side, i took it off again and proceeded round the corner quite normally. i was well shocked to say the least. but it worked!!!

back on subject though, the judder through the brake pedal is the pressure changing via the modulators. its perfectly normal for an emergency stop/ skid.

Jules59 · 31-05-2007, 23:47

Personal comment. I just find it worrying but not surprising that when people get a car they dont take it out and practise an emergency stop to get to feel how it behaves when you do this. ABS can save yours and others lives but only if the driver knows what to do with it when it becomes active. Its no good thinking whats that funny vibration in my right foot as you crash into the object directly in front. ABS does have limitations based mainly on tyres, the vehicle dynamics and road conditions, but too many people think it will somehow save them by magic and when it starts vibrating they panic and release pedal pressure. Thats why newer cars have emergency brake assist to keep the pressure on and use the ABS to its max advantage. My daughter is 17 next week, shes been driving my old V8 90 around fields for a few years now but she will be practising emergency stops in car very soon until I'm confident about her abilities. Also ABS keeps your tyres round.
Jules

mattbeef · 01-06-2007, 08:22

Quote:

Originally Posted by TeflonTom

And i thought that you were going to come up with the goods then Tom

30-05-2007, 16:18	#1
duke of hazzard Briskodian Join Date: Oct 2006 Location: leeds Posts: 325 Thanks: 10 Thanked 13 Times in 11 Posts	ABS question hi guys, just a quick question to all the octy owners who've had ABS kick in on them... when it kicks in i think that my brake pedal is actually rising an inch from where it was depressed to cause it to kick in. is this normal? having never had it before its quite disconserting to try emergency brake to have the pedal "lift off" of its own accord. whilst the abs is working it also appears to be impossible to depress the pedal further, is this supposed to be the case? i hope someone understands me out there? __________________ Mods, Colour coded grille, DVD player, Fancy headlights, Whooshy thing, One of them brillo pad filters where the car sucks air in, and windows upgrade on the cpu from ME to Vista!

30-05-2007, 16:19	#2
TeflonTom Briskodiodion Join Date: May 2006 Location: Hayling Island, Hampshire Posts: 7,980 Thanks: 43 Thanked 209 Times in 181 Posts	Re: ABS question air trapped in the abs hydraulic unit??? __________________ vorsprung durch czechnik

30-05-2007, 16:22	#3
duke of hazzard Briskodian Join Date: Oct 2006 Location: leeds Posts: 325 Thanks: 10 Thanked 13 Times in 11 Posts	Re: ABS question i dunno if anything is wrong or (and its probably this) im unfamiliar with the sensation of abs, i mean it stops like nobodys business anyway just curious inquirey. __________________ Mods, Colour coded grille, DVD player, Fancy headlights, Whooshy thing, One of them brillo pad filters where the car sucks air in, and windows upgrade on the cpu from ME to Vista!

30-05-2007, 16:25	#4
micndiesel Briskodian Join Date: Apr 2006 Location: nottingham Posts: 121 Thanks: 0 Thanked 5 Times in 5 Posts	Re: ABS question Never done a really hard break in my vrs but in a seat v5 i had a couple of years ago the abs used to make the pedal vibrate to calm you down, not sure if your car uses the same idea when it did it the first time after thinking i dmamged something i looked it up in the manual and it explained it and the reason behind it etc __________________ 360 gamertag:micndiesel psn gamertag :micndiesel

31-05-2007, 10:31	#6
mattbeef Briskodian Join Date: Apr 2006 Location: Sheffield Posts: 3,353 Thanks: 38 Thanked 116 Times in 115 Posts	Re: ABS question yea i didnt calm me down when i had it happen to me in the snow __________________ I few bits here and there but im happy to Performance Torque Go on click me you know you want to

31-05-2007, 10:39	#7
ap0gee ASZ Eternal Join Date: Aug 2004 Location: Leafy Chesh-shire Posts: 6,516 Thanks: 322 Thanked 315 Times in 271 Posts	Re: ABS question I seem to remember that when ABS first came out, it lead to an INCREASE in accidents, as people jammed on the brakes, felt the pedal vibrating, thought, "What the hell's that!?!", took their foot OFF the brake pedal, and drove merrily into whatever it was they were trying to avoid! One of the few occasions where 'consumer education' might have actually been worthwhile (thinking about these off-road courses Land Rover drivers get offered when their new purchases won't ever go near a muddy field, let alone a pile of logs or a giant see-saw ) __________________

31-05-2007, 12:47	#8
KenONeill Briskodian Join Date: May 2006 Location: Normally somewhere in Scotland! Posts: 10,381 Thanks: 56 Thanked 491 Times in 482 Posts	Re: ABS question Having tested the ABS "properly" (with a genuine emergency on snow), you're going some to set it off in the first place, but it does kick back a touch when it does. It's a vibration from the valves cycling, not any form of "pedal pusher" though.

31-05-2007, 14:19	#10
Lady Elanore Geordie Lass Join Date: Oct 2005 Location: in the ceiling watching you..... Posts: 10,241 Thanks: 214 Thanked 205 Times in 115 Posts	Re: ABS question My ABS is always going off when braking firmly in the damp and driving over manhole covers or other slippery objects. I find it comforting that when one wheel has slipped slightly, in the space of a couple of feet the car has recognised this action and already correct the skidding wheel by modulating the bake line pressure to the offending wheel. It is a marvellous invention. Most new cars (a la Octy II) have Brake Assist anyway, which detects panic breaking and applies maximum pressure almost instantaneously. I think it’s because many people when hitting the brakes (oh how often have most of us done this on a motorway when the car in front suddenly stops) hesitate slightly as to whether to give it 100% or not and by the time you realise that you should be giving it full effort its too late. The car recognises this dilemma and gives it 100%, after all it’s easier to lift off the brake than to reach full brake pressure. Some cars like Peugeots do this and put the hazard lights on too, once the brake pressure has reached 85% (or something like that) With regard to ABS and snow. I remember driving my Clio 16V one Christmas day, up the A1 and a car pulled over and nearly hit me. I swerved towards the central reservation where there was still a lot of uncleared snow from the previous day. My Clio’s front offside wheel was dragged further into the snow as the extra drag of the snow pulled the steering in that direction. I was doing about 80mph and couldn’t fight the wheel turning. I slammed on the brakes and waited for the graunching metal sounds as I hit the barrier……………..nothing happened, except the lovely modulation of the brake pedal. The car had 2 wheels on bone dry tarmac, 2 wheels in deepish snow all at 80mph and it was slowing down in a straight line!!!! I regained control pulled over to the hard shoulder and clipped the plastic lip under the front spoiler back into place. BL00DY marvellous thing ABS. __________________ . Amanda

31-05-2007, 17:49	#12
mattbeef Briskodian Join Date: Apr 2006 Location: Sheffield Posts: 3,353 Thanks: 38 Thanked 116 Times in 115 Posts	Re: ABS question i though that they had got rid of the fuse trick?? Just for errrrr diagnostics what number fuse would it be? __________________ I few bits here and there but im happy to Performance Torque Go on click me you know you want to

31-05-2007, 17:53	#13
TeflonTom Briskodiodion Join Date: May 2006 Location: Hayling Island, Hampshire Posts: 7,980 Thanks: 43 Thanked 209 Times in 181 Posts	Re: ABS question __________________ vorsprung durch czechnik

31-05-2007, 23:47	#15
Jules59 Briskodian Join Date: Oct 2005 Location: West Midlands, UK Posts: 319 Thanks: 7 Thanked 10 Times in 9 Posts	Re: ABS question Personal comment. I just find it worrying but not surprising that when people get a car they dont take it out and practise an emergency stop to get to feel how it behaves when you do this. ABS can save yours and others lives but only if the driver knows what to do with it when it becomes active. Its no good thinking whats that funny vibration in my right foot as you crash into the object directly in front. ABS does have limitations based mainly on tyres, the vehicle dynamics and road conditions, but too many people think it will somehow save them by magic and when it starts vibrating they panic and release pedal pressure. Thats why newer cars have emergency brake assist to keep the pressure on and use the ABS to its max advantage. My daughter is 17 next week, shes been driving my old V8 90 around fields for a few years now but she will be practising emergency stops in car very soon until I'm confident about her abilities. Also ABS keeps your tyres round. Jules

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