rear brakes gone

[Decsi Miklos <MDecsi@pgsm.hu>]

Hi!

Today my rear brakes stoped to work. The brake pedal can be pressed to the
2/3 of it's way and no brakes at all. At the last 1/3 there is brake and it
is very hard, nearly blocking.

 Tha car is a '83 80q. There are disc brakes at the rear. Break "insertion"?
(not sure how you call it, the small things that frets and has to be changed
regurally) has been changed just two weeks before by the previous owner. It
worked perfectly until now. There is enough brake fluid, so that is not the
problem. 

 Because of the special brakes the only place where I could take the car is
the audi dealer, but they work extremely expensive. Chanses that I would pay
50% of the price I bougth tha car for the repair at a dealer so I really
don't want to do that. 

 Can you recommend me something to check what could be the problem? Or maybe
a fix?

 DM

Ps: If you don't understand something just ask, english is not my strong
side.