S4 Brake Assembly an ABS sensor - Description?

[SonicDeathMonkey3]

My ABS light is off, but I am gettin the occasionl shudder though the brake pedal. I hve been told this could be a sensor needs cleaning.

Not that I am going to do this myself, but does anyone have any pictures of the assembly so I can understand the problem?

And what the hell are all those smilies??? Not noticed them before.

 

[aragorn]

the sensors are hall effect sensors and are mounted in the hub assy on the front and read off a toothed wheel on the CV joint, they can build up random bits of metal crap and this can effect their readings

you should be able to pull the sensor out of the hub, clean the sensor and the hole with solvent (brake cleaner or similar) and put it back, but they can be damn tight to get out

the rear ones on a fwd sit in the backing plate and read from a pickup wheel on the back of the disk. not sure about the quattro bit i'd imagine it'd be more like the fronts.