How do I flush my hydraulic hoses?
You should flush the hydraulic hose by connecting one end to the high pressure side of the pump then the other end directly to the return hose bypassing the servo valves. Alternatively, you can temporarily replace the servo valves with a flushing valve and flush the system that way. In either case, never flush a hose while connected through the servo valves.
After you flush the hoses and reconnect the system with the servo valves in line, the remaining air will be purged shortly after you run it the first time. Air will be pushed through the system until it returns to the hydraulic fluid reservoir which is vented to atmosphere.