uprated brakes... ABS too early

[karl.w]

last week i changed my front discs and pads to black diamond pads + drilled and grooved discs.

the brakes are now very very good but just 1 problem with them the ABS seems to cut in far too early.

Has anybody else had this problem and can fix it or change when the ABS cuts in somehow?

 

[Muttley]

The ABS can only cut in when it detects that your wheels are on the point of slipping. In other words, your brakes are now so good that you are almost provoking a skid much more often. The only way to get round that is to put better tyres on........

 

[F2 Stu]

Not quite, the Antliock Bracking System is simply kicking in earlier as its not used to better discs & pads which have far more bite.

Or your being too over zealous as you have 'yay, Ive got new brakes'.......

 

[karl.w]

Not quite, the Antliock Bracking System is simply kicking in earlier as its not used to better discs & pads which have far more bite.

Or your being too over zealous as you have 'yay, Ive got new brakes'.......

its not that im being over zealous

it dosent feel like the wheels are about to lock when the ABS cuts in.

Dose vag-com let you adjust the ABS settings?

 

[F2 Stu]

Pass.

When I fitted my 4 pots, I pulled out the ABS relay on mine.

 

[ibizacupra]

be very careful if you pull the fuse on the ABS oncars without mechanical bias valve to rears. you WILL spin.

Is ths car std suspension? are the rear locking up due to more braking effort on front and diving more, so less rear grip, hence rears locking and provoking ABS to come in.

ibiza abs system is crude and nasty.
removed from mine, down right dangerous IMHO - leons much better

 

[cupra_matt]

I see this fault quite abit on VAG cars and it is normally a incorrect air gap on one of the speed sensors.

 

[ibizacupra]

would'nt it show an ABS fault with a gap problem? intermittent sensor or something? as opposed coming in too early?
whats the symptums?

 

[karl.w]

i have to be breaking quite hard for this to happen but it still feels the ABS should not come on for a few more seconds as there is still loads of grip at the front wheels.

the back however dosent lock up but it dose go very very light and moves around alot.

dont no if i would fancy it on a trackday

 

[Muttley]

karl.w wrote

i have to be breaking quite hard for this to happen but it still feels the ABS should not come on for a few more seconds as there is still loads of grip at the front wheels.

You get the best braking effort just before the tyre begins to skid. ABS keeps the tyre on the edge of losing traction much more effectivly than you or I can. To improve your braking performance and push back the point where ABS cuts in, use better tyres

the back however dosent lock up but it dose go very very light and moves around alot.

The front and rear circuits are separate; ABS can be modulating the rears while still keeping full braking on the front. Each front wheel is separately modulated, too. You should find more braking is available if it is only the rears that are near to skidding - but you need a large empty space to check it out, certainly not on the open road. Big car park, after hours?

 

[ibizacupra]

The front and rear circuits are separate; ABS can be modulating the rears while still keeping full braking on the front. Each front wheel is separately modulated, too. You should find more braking is available if it is only the rears that are near to skidding - but you need a large empty space to check it out, certainly not on the open road. Big car park, after hours?

Not on a mk3 ibiza cupra

when ABS is in its in and you loose front brake efficiency massively...
happened to me many a time.

much more physical front grip remaining, ABS is premature in coming in because of rears going light, hence locking.... You would'nt know they were locking as its ABS'd innit Fix this and its a lot better.

Without ABS and with mechanical biasing to reduce rear pressure (which are too high) then you get significantly better braking effort.

Mk3 Ibiza ABS system is akins to an old Ford Granada apparently, and certainly not high tech or nice.

Rear stability can also be aided by spacers on the rear wheels to increase track width to match the fronts.

 

[cupra_matt]

would'nt it show an ABS fault with a gap problem? intermittent sensor or something? as opposed coming in too early?
whats the symptums?

Normally the ABS cuts in just before you stop, the problem being a slightly larger air gap on one sensor, so at low speeds the signal is very weak and the ECU thinks the wheel has locked hence the ABS cuts in,

This fault has never put a fault code in the memory that i have seen.

Another thing i have seen on certain models is a split sensor wheel causing an irregular signal.

Its worth checking and comparing the wave pattern from the sensors on an oscillascope, if poss.

 

[ibizacupra]

Normally the ABS cuts in just before you stop, the problem being a slightly larger air gap on one sensor, so at low speeds the signal is very weak and the ECU thinks the wheel has locked hence the ABS cuts in,

This fault has never put a fault code in the memory that i have seen.

Another thing i have seen on certain models is a split sensor wheel causing an irregular signal.

Its worth checking and comparing the wave pattern from the sensors on an oscillascope, if poss.

now thats damned interesting.

not sure mine had this fault but it had diabolical abs system.

I have logged wheel speed sensors off the abs and they always tracked. I would have thought a weak sensor signal would somehow provoke a logged code, but does'nt sound like it.
maybe its an ibiza "thing" - good info