What was found
AFTER CREW LOWERED MAIN LANDING GEAR, POWER BRAKE ANNUNCIATION LIGHTS ILLUMINATED. CREW REQUESTED A GO AROUND TO CHECK ISSUE AND RUN CHECKLIST. CREW REQUESTED LONGER RUNWAY AND LANDED WITH LOW BRAKE PRESSURE. CREW USED REVERSE THRUSTER TO SLOW AIRCRAFT AND EXITED RUNWAY AND STOPPED ON TAXIWAY. FBO TOWED AIRCRAFT IN. TECH IN KOMA WAS CONTACTED TO TROUBLESHOOT ISSUE. FLUID WAS FOUND IN LEFT GEARWELL AND BRAKE RESERVOIR EMPTY. BRAKE RESERVOIR WAS SERVICED AND BRAKE SYSTEM OPS CHECKED. MAINTENANCE FOUND A LEAKING LEFT BRAKE LINE DUE TO SWEDGING FAILURE AT COUPLING NUT. NEW BRAKE LINE WAS ORDERED FROM AND LINE WAS REPLACED THE FOLLOWING DAY. BRAKE SYSTEM WAS CLEANED OUT, SERVICED, AND BLED. AIRCRAFT RETURNED TO SERVICE.