What was found
(CAN) DURING A FLIGHT, THE TRANSITION LIGHT CAME ON AND THE LIGHT INDICATING THAT THE HYDRAULIC PUMP IS WORKING WAS OFF. EMERGENCY GEAR EXTENSION CUTOUT. IT WAS LATER FOUND AT THE HANGAR THAT SOLENOID VALVE, PN 25400 WAS DIRTY AND WAS NOT CLOSING PROPERLY ALLOWING THE PUMP TO RUN FOR A LONG TIME. THE PUMP BREAKER FINALLY OPEN SHUTTING DOWN THE PUMP. SOLENOID VALVE WAS CLEANED AND REINSTALLED RETRACTION CUTOUT WITHOUT ANY OTHER PROBLEM. INSPECTION OF ALL THE HYDRAULIC LANDING SYS CUTOUT. THIS ACFT IS EQUIPED WITH LANDING GEAR SYSTEM, STC SA 4013 WE.