ABS screwing around!

[Ferret]

Okay so it seems everything is coming together in one lump, it rained here for the first time the other day, and doing some "mild" braking while some idiot with an IQ of 10 pulled out on me, the front left wheel locked, and stayed locked.

On startup, the ABS light comes on, but goes off again - I didnt see whether the abs lamp was flashing while trying to avoid the oncoming car, but is this a common fault?

The ABS system doesnt seem to think it's got a fault, I guess I need to get it on wet grass and find out if the lamp flashes under heavy braking...

[Tiger]

It depends on the speed and intensity that you slammed on the brake. Test it on quiet street and on a dry day to see if it is working properly.

[whiskychaser]

In my experience ignition on gives ABS light. Fire up and it goes out. ABS doesnt start to monitor until you reach 10 kmph. If it comes on at that I'd guess sensor. You can check the resistances easily with a DMM. This doesnt take into account idiots with an IQ of 10. They come under 'i' for idiots in the manual which includes those who dont know how to join/leave a motorway

[BennyM]

The ABS light doesn't blink like the ASC light when it's doing its magic.

When you say the wheel locked up, do you mean, it locked up while your foot was on the brake or that it stayed locked until you restarted the car?

[Ferret]

The ABS light doesn't blink like the ASC light when it's doing its magic.

When you say the wheel locked up, do you mean, it locked up while your foot was on the brake or that it stayed locked until you restarted the car?

It locked up under braking, resumed normal service with foot off the brake :)

[philbyil]

Pull the wheel and check your toothed ABS ring. Make sure it doesn't have any crud in it ;)

[whiskychaser]

For the MOT you need the bulb to come on with ignition on then go out when you fire it up. The abs light doesnt flash when the abs comes in so you might not need to go grass cutting. Well unless you want to? :D If you were doing, say 30 and it locked up at that, you have a fault. As I said above, up to 10kmph and I'd say thats 'normal'

Some different ways to check sensors:
http://www.topbuzz.co.uk/maintenance/testing_abs/testing_abs.htm

[tim eh?]

I'm not sure I understand why this is an abs fault, couldn't it be something wrong with the caliper or something else in the brake?

[mzarifkar]

I would make sure that the toothed ring is clean as well, and make sure your ABS sensor, (essentially a magnet) is not covered in metallic waste. The sensor reads the ups and downs of the toothed ring, as a way to assure the wheel is still rotating, interference here might cause your problem.

also, even with abs braking, you will still hear tires screech and you may still leave rubber on the pavement

[Ferret]

Found out today (much to my embarrasment) that the calipers are sticking on the front - if you try and emergency stop the front right wont brake at all, then suddenly the front left will lock with a horrific squealing noise.

Need to take 'em apart next weekend and get new pads fitted as the ones currently there are quite low, I think the calipers have reached the extent of their travel...