The thing to think about is what else is gone.
If you are presented a plane with duff brakes, and they know about it and expect you to fly it, do you think it's had gold plated maintenance on everything (or anything) else?
The chances are it is owned by a total cowboy outfit which gets maintenance done "on the nod" i.e. just enough to function but obviously with all the boxes ticked and all the papers stamped as always.
Unfortunately, you don't need to read many accident reports, literally or between the lines, to realise that in aviation crap attitudes to risk go hand in hand with a whole lot of other dodgy stuff. So e.g. the plane might not be insured...
If youa re not happy, take a walk somewhere else. There are schools out there with decent planes and decent attitudes. Not many but there are some. I walked out of a school over dodgy maintenance practices during my PPL training, too.
Maintenance is no rocket science. You don't need to even read or write to be able to fix brakes on a common type of aircraft.