What was found
PARK BRAKE ON AMBER CAS: IN FLIGHT, AFTER LANDING GEAR WAS EXTENDED, THE AMBER PARK BRAKE ON CAS ILLUMINATED. RAN QRH, AND YES, PARKING BRAKE HANDLE WAS STOWED. LANDED NORMALLY. PARKING BRAKE FUNCTIONS, EXCEPT WHEN YOU PRESS HANDLE DOWN, PARK BRAKE LOW PRESS CAS DISPLAYS.// SIGN OFF // REMOVED AND REPLACED PARKING BRAKE SWITCH WITH A NEW CUSTOMER SUPPLIED SWITCH WITH REF TO CE680A MM CHPT 32-44-15. OPERATIONAL CHECKS SATISFACTORY.