I am in the process of designing a homemade FEL for my MF1528. To simplify connecting to existing hydraulics of tractor I plan on ordering the piping outlet option AGCO part # 6243908M92 from MF. My question is that there appears to be three lines coming off this block. AGCO parts diagram for the 1520 loader shows three hoses hooking to valve. Most valve schematics show a inlet and a outlet. What is the purpose of the third hose?