Toyota Repair: toyota 1996 corrolla brake cylinder/drum leakage, toyota corolla, drive belts

Question
I have a Toyota corolla 1996 model with 111000 miles on it.No failure with this car till now.I have two questions
1.I get a "squeaking" sound near the belts while reversing.I showed it to Toyota dealer , they repaired it by tightening the pulleys, but the noise has started comning again.
2.While getting a tire change , the mechanic showed me a very minor leak from the break cylinder (The cylinder is 3" long and is visible after removing the rear tire)He said that the breaks will function in normal way for 4-5 months .How serious is the problem.What all is to be changed to repair this leak.Should it be done immediately.

Answer
Replace all the drive belts to eliminate the squeeking noise.
If the wheel cylinders are starting to leak they will need to be replaced, I advise you to get another opinion about the cylinder leak from a Toyota dealer. I don't trust most of the tire places.