Anyone got ABS knowledge ?

[Carol Anne]

ABS light on Rover 825 was lit for a few months til I had a diagnostic done at the dealer, where the FNS sensor showed faulty. Got it fixed and within a day or so the light is on again. Took back and diagnostic apparently says that FOS sensor has now gone. What a coincidence I thought, but garage say that this is normal, and that they usually fail in sequence. Is that right? If so then if one goes then you would be looking at replacing all 4 within a very short time. It all sound like a bit of flannel to me. Ive seen of these things and I would have thought that only physical damage or corrosion would cause it to fail. Any informed comment would be most welcome. Thanks

[qapmoc]

I agree that your opinion is correct but there is another thing which makes them stop working but which is easily fixed, the sensors are magnetic and if there are particles of metal or rust around they will attract them and get coated on the tip and then they won't work. remove them and look at the tip, if it is coated with little particles just remove them and put them back in place and see if it works OK.
The next thing is to wonder where the metal particles came from????