lack of brake hydraulic pressure after park brake usage

[Greg Sbroglia]

I lost toe brake operation on the right side after use of the park brake system. There are no signs of leakage and the pedal will pump up after many pumpings but will not hold. Any ideas.[/list]

[Andrew Foster]

I would favor a guess at air in the line. Time to bleed the brakes

[Zach Grant L1011jock]

The integral parking brake valves are leaking on your master cylds. They need to be removed and the master cyl and valves need to be rebuilt (the directions and parts are outlined in the appropriate parts and maint. manual for your particular airplane.
-Zach