All solenoid valves and other electronic controls are in a control box, mounted out of the way under the edge of the spreader in a heavy duty weather tight box. Mounted in front of the control box is a full flow oil filter. All oil entering the hydraulic pumps is filtered.The entire system has been designed with the thought of eliminating as many problems as possible. From the control panel in the cab to the control box, the components that make up the brain of an FSI EzSpred Fp are protected from the dirt and acids the can cause a system to fail. No control cables are used, so you don't have to worry about cables becoming rusty and failing.