What was found
(CAN) 'A' SYSTEM LOW LEVEL LIGHT ILLUMINATED, 'A' SYSTEM QUANTITY DOWN TO 2 GALLONS AFTER GEAR RETRACTION. CREW RETURNED TO DEPARTURE WITHOUT FURTHER INCIDENT. MAINTENANCE ARRIVED AND INSPECTED AIRCRAFT AND FOUND 3 GALLONS INDICATING. FOUND SMALL LEAK ON B-NUT ON TAIL SKID ACTUATOR. ALSO FOUND HYDRAULIC QUANTITY TRANSMITTER STICKING ON 'A' SYSTEM RESERVOIR, INDICATION FLUCTUATED +/- 1.5 GALLONS BY TAPPING ON TRANSMITTER. TRANSMITTER REPLACED ENGINE RUNS CARRIED OUT WITH NO FURTHER LEAKS FOUND AND INDICATION WORKING CORRECTLY.