What was found
WHILE TAXIING, THE PILOT ATTEMPTED TO EXECUTE A RT TURN. THE RT BRAKE PEDAL WENT SOFT & THE ACFT STOPPED TURNING & TAXIED STRAIGHT FWD. THE PILOT CLOSED THE THROTTLE & STOPPED, BUT THE ACFTS NOSE & LT TIRE WENT INTO THE GRASS. THE ACFT COULD NOT BE MOVED WITH DIFFERENTIAL POWER SO THE PASSENGERS WERE OFF LOADED & TRANSPORTED BACK TO THE TERMINAL. MX INSPECTED ALL COMPONENTS & FOUND THE RT CYLINDER FLUID LEVEL LOW. THE RT CYLINDER WAS SERVICED IAW MM CHAPTER 12-10-05. THE ACFT WAS FUNCTIONALLY TESTED & NO DEFECTS WERE NOTED.