ABS Bypass ?

Author
Discussion

Tony V8

Original Poster:

54 posts

121 months

Sunday 19th April 2015
quotequote all
Is it illegal to bypass the abs system on your car and revert to a conventional braking system?
I am not asking if it is wise, just legal or not.

Zoobeef

6,004 posts

159 months

Sunday 19th April 2015
quotequote all
For an MOT if it's there it must work. If it has been removed then that is ok as long as it's not just disabled and test lights on etc.

Insurance would need informing if it's removed though.

I know a fair few that fit a switch and turn it off when then don't want it. Mine is disabled on my track car and my road car doesn't have any from new so it's not always a good thing to have it and also not always a bad thing.

With these feet

5,728 posts

216 months

Sunday 19th April 2015
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Tony V8 said:
Is it illegal to bypass the abs system on your car and revert to a conventional braking system?
I am not asking if it is wise, just legal or not.
Would say its not advisable, seeing as it makes the car unroadworthy from an MOT point of view.

In real world terms I cant remember the last time I had it kick in, but it is a safety issue and if there was an accident Id guess the insurers wouldnt be too chuffed.

Retroman

969 posts

134 months

Sunday 19th April 2015
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With these feet said:
Would say its not advisable, seeing as it makes the car unroadworthy from an MOT point of view.
Nope.

If the ABS pump has been removed and the wiring / sensors then it would be a pass and advise.
It's ok to still have the ABS rings on the drive shafts / discs

TooMany2cvs

29,008 posts

127 months

Sunday 19th April 2015
quotequote all
Tony V8 said:
Is it illegal to bypass the abs system on your car and revert to a conventional braking system?
I am not asking if it is wise, just legal or not.
Illegal under C&U? Probably not.

But http://www.motinfo.gov.uk/htdocs/m4s03000401.htm

Tony V8

Original Poster:

54 posts

121 months

Sunday 19th April 2015
quotequote all
How would it be unroadworthy as long as the brakes were upto required level and in balance on the rollers it should pass, my vehicle is available without abs, and on my insurance docs it says its not fitted anyway, (I have tried to change this detail twice but it keeps coming back as non abs).

mcford

819 posts

175 months

Sunday 19th April 2015
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Non ABS usually have a way of limiting the braking effort to the rear brakes so as to avoid rear wheel lock up. A car with the ABS removed, won't have this.

Tony V8

Original Poster:

54 posts

121 months

Sunday 19th April 2015
quotequote all
mcford said:
Non ABS usually have a way of limiting the braking effort to the rear brakes so as to avoid rear wheel lock up. A car with the ABS removed, won't have this.
True mcford, my vehicle is fitted with a mechanical load sensing valve to the rear axle for this purpose.

With these feet

5,728 posts

216 months

Sunday 19th April 2015
quotequote all
That is IMO quite bizarre with it being acceptable to remove it. Seems crazy that the abs system is there to help in an emergency where a standard system could possibly lock and/or cause an incident.
Some cars have all the systems linked, abs, tc and sc, so would lose the lot. Would you feel comfortable in an old A class with the electronics removed?

Could it however affect your premium with insurers down to the potential differences in braking distances etc?


TooMany2cvs

29,008 posts

127 months

Sunday 19th April 2015
quotequote all
With these feet said:
That is IMO quite bizarre with it being acceptable to remove it. Seems crazy that the abs system is there to help in an emergency where a standard system could possibly lock and/or cause an incident.
Some cars have all the systems linked, abs, tc and sc, so would lose the lot. Would you feel comfortable in an old A class with the electronics removed?
You seem to forget that not every car on the road was designed with electronic bottom-wipers being necessary to save the day. Some were designed without them, and some modern ones might not require them in order to work around abysmal failures in dynamics.

Even then, if you drive within the dynamic envelope of the car, you'll probably not die fourteen times before breakfast. Remember, ABS does nothing until you lock the brakes. TC does nothing until you spin the wheels. ESP does nothing until you start to exceed cornering grip.

Not every pre-recall A-class or TT landed on the roof.

I possess exactly two vehicles with anti-lock brakes. Both are firmly designed in. However, both of them are down to inadequate brakes, rather than electronics... I haven't died yet. Today.

With these feet said:
Could it however affect your premium with insurers down to the potential differences in braking distances etc?
In a world where insurers can ramp premiums or refuse to quote because of far less major changes...? Ooh, lemme think...

Retroman

969 posts

134 months

Sunday 19th April 2015
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Tony V8 said:
True mcford, my vehicle is fitted with a mechanical load sensing valve to the rear axle for this purpose.
As far as i'm aware, if you remove the ABS then that valve still works.
When more weight is on the rear, it changes position of the valve so more weight is distributed towards the rear.
It's found on vehicles with ABS, but as far as i'm aware (on older vehicles at least) it still works with the ABS removed

TooMany2cvs

29,008 posts

127 months

Sunday 19th April 2015
quotequote all
Retroman said:
As far as i'm aware, if you remove the ABS then that valve still works.
When more weight is on the rear, it changes position of the valve so more weight is distributed towards the rear.
It's found on vehicles with ABS, but as far as i'm aware (on older vehicles at least) it still works with the ABS removed
And it isn't on all vehicles without ABS. Quite often, estates would have it (plus larger rear brakes), and saloons/hatches wouldn't.

anonymous-user

55 months

Sunday 19th April 2015
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TooMany2cvs said:
I possess exactly two vehicles with anti-lock brakes. Both are firmly designed in. However, both of them are down to inadequate brakes, rather than electronics... I haven't died yet. Today.
Don't understand. The brakes are working well enough to lock the wheels, so once you're at that point the brakes have no relevance whatsoever as long as they can still apply that level of braking force. The limiting factor is your tyre grip. ABS allows you to have steering control, without ABS you have to cadence brake to be able to steer and frankly when the st's hitting the fan I'd rather trust the ABS pump to do that than my foot.

TooMany2cvs

29,008 posts

127 months

Sunday 19th April 2015
quotequote all
charltjr said:
Don't understand. The brakes are working well enough to lock the wheels
Exactly... That bit - not.

We're talking about an old Landy and a VeloSlowlex, though, so at least the brakes are commensurate with the performance.

Retroman

969 posts

134 months

Sunday 19th April 2015
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That's similar to my experience with my 1999 Corsa B.
ABS fitted as standard but when i fitted 15" alloys with nice sticky tyres the brakes were never good enough to lock up the wheels so ABS was a bit redundant unless it was snow / ice.

anonymous-user

55 months

Sunday 19th April 2015
quotequote all
Ah! Now I get what you were saying, thanks for explaining.

Mr2Mike

20,143 posts

256 months

Monday 20th April 2015
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charltjr said:
Don't understand. The brakes are working well enough to lock the wheels, so once you're at that point the brakes have no relevance whatsoever
An incorrect, but fairly common assumption.

With these feet

5,728 posts

216 months

Monday 20th April 2015
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As Ive said, we run Vantages that had the road car ABS which also run on slicks.
The drivers did not know just how much they relied on the system when braking until a number of wheel speed sensor failures brought it to light. If one fails, the fail-safe is ABS of and a light appears on the dash. OK in a road car but youre not really looking that hard at the dash when concentrating on the track.
Subsequently, the driver didnt notice the light and hit the brakes as usual - hot 10" slicks on a dry circuit. The result of which was all 4 wheels locked and 120 yrds of black lines into the gravel. The driver declared the brakes had failed when in fact they had simply locked. Before the problem, the drivers never once said they felt the ABS cutting in or working, it was there in the background preventing issues. Im not so up to date with ABS systems across the board, but obviously the days of massive pedal kickback showing its working are gone?

jbsportstech

5,069 posts

180 months

Monday 20th April 2015
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I think your on dodgy grounds using it on public highway/car insurance as you have disabled a safety feature. Also as someone has said I believe vosa want mot tester to fail for warning lights on dashes and if you abs/brake warning light comes on that could be an issue.

If for track use up to you I suppose not sure other than race use why would you want to disable it on a road car.

Retroman

969 posts

134 months

Monday 20th April 2015
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jbsportstech said:
I think your on dodgy grounds using it on public highway/car insurance as you have disabled a safety feature. Also as someone has said I believe vosa want mot tester to fail for warning lights on dashes and if you abs/brake warning light comes on that could be an issue.

If for track use up to you I suppose not sure other than race use why would you want to disable it on a road car.
All you need to do insurance wise is declare the ABS as being removed from the vehicle.
It's a modification and they can adjust or cancel the policy (some don't like mods)

In terms of MOT, as long as the ABS pump and sensors have been removed and the light doesn't come on, all is fine (remove bulb if need be but normally ECU for ABS is on pump so when pump removed, no light)

In terms of legality, it's not illegal to drive or own a car without ABS so should be fine.