Non Residue Brake Kleen, comes in a spray can, take it apart, clean them off, lubricate the equalizer and cables. If the brake line is leaking, you are more than likely going to have to replace the line, the flexible hose. In all honesty, it doesnt matter if your Dad released the brakes, every time you use the brakes, it activates the rear brakes a little bit at a time too. So they are going to grab again. Its not all that hard to fix, just get a hanes book or go to ALLDATAdiy.com Leading Source of Factory Automotive Repair Information
and get an online repair manual. It will give you all the specs and steps necessary for a proper repair job.