What was found
MAIN HYD QTY LOW CAS ILLUMINATED IN FLIGHT. FLIGHT CREW REQUESTED TO DIVERT FOR THE LONGER RUNWAY. AN EMER WAS DECLARED. EXPERIENCED NORMAL BRAKING ON TAXI & LANDING. UPON PARKING FOUND HYD FLUID LEAKING FROM BELLY OF ACFT. FOUND THE MAIN HYD BOWL LEAKING. THE PACKING WAS CUT IN 2 PLACES. THE PACKING, BACK UP RING & FILTER ELEMENT WERE REPLACED. SYS WERE CYCLED DURING GND RUNS. LEAK & OPERATIONS CHECKS WERE GOOD & THE ACFT RETURNED TO SERVICE