ABS fault

[Wadders]

Just brought a 2000/X 1.7 lux with 53k miles. Car has new mot and had a wheel sensor replaced to pass. Car drives well, brakes ok, but abs pulsates thru pedal as you coast to a low speed stop. No warning lamps on, they come on with ignition and go off after a couple of secs. Abs self checks at 12 mph. Ford dealer says it needs a new modulator??

 

[Wild E. Coyote]

check the gap between sensor and the tone ring. If they are not the same, it will behave as you say. The proper gap is 0,6 mm (tolaerance range is 0,2 - 0,8 mm)

 

[Wadders]

Thanks for the advice, would that be on the front brakes or all four please?

 

[748]

check the gap between sensor and the tone ring. If they are not the same, it will behave as you say. The proper gap is 0,6 mm (tolaerance range is 0,2 - 0,8 mm)

This is most likely the problem, the system is thinking it's a genuine wheel lock up at slow speed so ABS kicks in. One of the sensors is low signal at low speed, more likely at the rear.
Ford dealer would say it needs a new modulator, 'about £800 please sir' :lol:
Paul

 

[Wadders]

Thanks Paul, thats exactly what they said... Ford want over two grand for a modulator!

 

[red]

Did you tell them you can buy 2 reasonable condition Pumas for that and probably have change?

 

[Wadders]

Yes I did funny enough! The chap was quite apologetic actually and said he wished that Ford still made Pumas! "we's sell every one we could get".

 

[Wild E. Coyote]

Thanks for the advice, would that be on the front brakes or all four please?

Most probably at rear. Maybe one of the tone rings is covered in brake dust which has baked it self over time in nice crust and that is fooling ABS.
Take the drums off and clean it, probably that will be enough :wink:

 

[Glenn_]

I would also say the gap is wrong or there Is muck on the sensor or pick up ring.

 

[Wadders]

Massive thank you for the advice regarding the sensor to ring gap. Finally had a chance to look and sort it out - the gap on the sensor fitted by the MOT garage was miles out. Had to remove sensor, clean rust from hole and base plate and refit. Best gap we could get was 0.8, but now works perfectly, no issues.


This fault was really grating on my nerves, but now its cure I'm back in love again

Thanks again, couldn't have fixed this without your advice. Pah to Ford deal

 

[Wadders]

....pah! to Ford main dealer who said it needed a new modulator for £2,000. Total cost of repair = nothing! Diy job.

 

[Glenn_]

Glad you got it sorted matey. Its good when you fix an annoying problem.

 

[Wadders]

Cheers Glenn...