brakes question

Hello,

I just changed the front pads today as they were really low. mot is tuesday *crosses fingers*. my question is, the pads i removed were 2-3ml lower 1cm in width all across the outer edge on the friction material. i dont know if that makes sense, basically they were worn more on the outer bit. as a consequence the disk had a lip that must have worn the pad this way. it was only on the inner pad, but it was the same both sides.

what would cause this?

corrosion, sounds like you should have replaced discs as well.

it was standing for a while before i brought it come to think about it... I didnt know the disks were like this with it being on the reverse side. Nobody had the disks in stock today, and what with my mot tuesday i just ground off the lip on the disks and fitted the new pads.