What was found
AFTER NORMAL PREFLIGHT, STARTUP AND TAXI, ALL ITEMS CHECKED GOOD. HYDRAULIC PRESSURE AND VOLUME CHECKED NORMAL OPS. AFTER TAKEOFF UPON GEAR RETRACTION, CAS MESSAGE INDICATED LOW HYDRAULIC PRESSURE L-R MESSAGE. GEAR WOULD NOT RETRACT. CONTACTED ATC ABOUT POSSIBLE ISSUE AND LEVELED AT 3000 FT. INSTRUCTED SIC TO GET QRH AND ASKED FOR ATC FOR VECTORS TO RUN CHECKLIST. PER CAS MESSAGE, REFERENCED AMBER P1 HYDRAULIC PRESSURE LOW L-R IN QRH. FOLLOWED CHECKLIST WHICH INSTRUCTED US TO USE THE BLOWDOWN BOTTLE TO GET GEAR IN LOCKED POSITION. AFTER THE GEAR WAS DOWN AND LOCKED RECEIVED VECTORS TO BURN FUEL UNTIL BELOW LANDING WEIGHT. DIVERTED TO CVG FOR THE LONG RUNWAY. UPON LANDING EMERGENCY BRAKING WAS USED TO SLOW AIRCRAFT WHICH RESULTED IN A FLAT OUTBOARD LEFT TIRE. FBO TOWED AIRCRAFT TO THE RAMP. CONTACTED COMPANY AND MAINTENANCE TO FOLLOW UP.