Tthe left brake pedal in my 231 lost all hydraulic fluid. There was evidence that fluid had leaked past the piston o-ring in the brake assy. I am replacing the o-ring and I am back bleeding the brake system through wheel cylinder bleeder valves using pressure pot. Using this method is there a need for pumping the brake pedals? Service manual states that the brake pedal should be "pulled back" (section 12-20-05). Any helpful suggestions out there from folks that have experience with brake bleeding mooneys. Does raising nose wheel off the ground help? What will be indication that the master cylinder needs servicing? Thanking you in advance for your help. peter lamberty N322DB