G
Guest
Guest
Chas
| I have had a slight problem with my brakes too, When coming to a halt
after
| slow moving (in a traffic jam), at the last moment, just as the
Cruiser
| comes to a halt I get a very slight pulse, just one, from the pedal
and the
| brakes pull to the right, this ONLY happens after slow movement NEVER
when
| driving faster.
| I assume it is something to do with the ABS but why does it only seem
to
| effect one wheel, I would have thought it would effect the whole
braking
| system?
This is absolutely normal for an ABS problem, and I had very nearly
identical symptoms.
What is happening is that a sensor has either failed, or is getting a
poor signal, and it thinks that its wheel has stopped turning when in
fact it is still moving. It occurs just before a halt because that is
when the signal to noise ratio is worst. I found that the symptoms were
provoked when coming to a gradual halt, as you describe, or when
trickling v. slowly downhill on the brakes.
The fact that you get a pull to one side suggests that it is a front
sensor, and it will be on the opposite side to the pull. (Since the
failed side will be pulsing and giving less braking effort.)
First check the wiring at the sensors, looking for dislocation or
damage. It's worth checking the wiring all the way up to the ABS
actuator (LHS of engine compartment next to windscreen washer bottle if
you have a diesel).
However it's more likely either that the sensor has failed or - quite
common - that it has a build up of gunge and iron filings on its tip
that is reducing the magnetic field at that wheel.
If the wiring looks OK then - carefully - remove the sensor, clear any
gunge out of the hole & the toothed ring, and make sure it is screwed
fully back in when replaced to give the correct gap between sensor tip
and toothed wheel.
If none of this works, or it breaks when you remove it (according to the
Toyota mechanic who did mine this can happen if the old sensor has got
corroded into the hole) then you need new front sensors. Unfortunately
you can't buy separate ones and you have to get the front pair plus
wiring harness from Toyota - not cheap. If you get to this point I
suggest taking it to a Toyota agent and getting them to plug their
computer thingy into the ABS diagnostic port to check the system.
In my case I got the pulsing you describe, but no pull to one side. It
was a back sensor that had been pushed away from its toothed ring by a
build-up of crud. However yours sounds like a front one.
Finally I'm afraid that while I can describe the problem and the
solution I can't give you a blow by blow mechanic's account of how to
fix it, since I paid Mr Toyota to do it for me. However it took a year
and repeated attempts to get to the bottom of it all, and I ended up
understanding far more about ABS than I really wanted to!
I hope this helps
Christopher Bell
____________________________________________________________
Electronic mail messages entering and leaving Arup business
systems are scanned for acceptability of content and viruses
| I have had a slight problem with my brakes too, When coming to a halt
after
| slow moving (in a traffic jam), at the last moment, just as the
Cruiser
| comes to a halt I get a very slight pulse, just one, from the pedal
and the
| brakes pull to the right, this ONLY happens after slow movement NEVER
when
| driving faster.
| I assume it is something to do with the ABS but why does it only seem
to
| effect one wheel, I would have thought it would effect the whole
braking
| system?
This is absolutely normal for an ABS problem, and I had very nearly
identical symptoms.
What is happening is that a sensor has either failed, or is getting a
poor signal, and it thinks that its wheel has stopped turning when in
fact it is still moving. It occurs just before a halt because that is
when the signal to noise ratio is worst. I found that the symptoms were
provoked when coming to a gradual halt, as you describe, or when
trickling v. slowly downhill on the brakes.
The fact that you get a pull to one side suggests that it is a front
sensor, and it will be on the opposite side to the pull. (Since the
failed side will be pulsing and giving less braking effort.)
First check the wiring at the sensors, looking for dislocation or
damage. It's worth checking the wiring all the way up to the ABS
actuator (LHS of engine compartment next to windscreen washer bottle if
you have a diesel).
However it's more likely either that the sensor has failed or - quite
common - that it has a build up of gunge and iron filings on its tip
that is reducing the magnetic field at that wheel.
If the wiring looks OK then - carefully - remove the sensor, clear any
gunge out of the hole & the toothed ring, and make sure it is screwed
fully back in when replaced to give the correct gap between sensor tip
and toothed wheel.
If none of this works, or it breaks when you remove it (according to the
Toyota mechanic who did mine this can happen if the old sensor has got
corroded into the hole) then you need new front sensors. Unfortunately
you can't buy separate ones and you have to get the front pair plus
wiring harness from Toyota - not cheap. If you get to this point I
suggest taking it to a Toyota agent and getting them to plug their
computer thingy into the ABS diagnostic port to check the system.
In my case I got the pulsing you describe, but no pull to one side. It
was a back sensor that had been pushed away from its toothed ring by a
build-up of crud. However yours sounds like a front one.
Finally I'm afraid that while I can describe the problem and the
solution I can't give you a blow by blow mechanic's account of how to
fix it, since I paid Mr Toyota to do it for me. However it took a year
and repeated attempts to get to the bottom of it all, and I ended up
understanding far more about ABS than I really wanted to!
I hope this helps
Christopher Bell
____________________________________________________________
Electronic mail messages entering and leaving Arup business
systems are scanned for acceptability of content and viruses