First look at the inside of the master from the lever and check the boot to see if it is rotted out and has been letting grime into bore. If so then take it apart and clean it real good then either kit it or wet it with fresh fluid and reassemble. It may be good to do the same to the slave cyl. Then a real good bleed job to remove any and all air. This is common with the clutch and brake masters being in the wind.
make sure the holes inside of the master is clear and clean.
'97 VN1500 91 Cubes Of Custom CLASSIC
Vance & Hine 2to1
engine, forks, ignition & carb mod's
WebCam cam & rockers hard weld & grind
NEW TOP END, NO LOOKS ALL GO GO
Maxx intake manifold system & super G carb 44mm