Strange problem with breaks on A4.

[Matt K1064]

Hello All,

Any views, opinions on the following gratefully received.

Strange problem with the wives car - 2001 Audi 1.8 A4 estate (older shape) 85,000 miles.

Strange noise coming from the brakes, a kind of thud / drone that lasts for about 1-2 seconds and appears to be emanating from the ABS pump. You also feel a slight change in resistance from the pedal. This typically happens under light breaking when the car has nearly stopped, maybe 5mph.

I'm guessing the ABS pump has died. If you disconnect the pump and run the system as non ABS it behaves normally. I'll probably replace the pump but am concerned that maybe a duff wheel sensor could also cause this?

Any ideas?

Cheers,

Matt