AGCO | Pressure Relief Valve - Acw108829AAGCO Parts Genuine pressure relief valves are designed and manufactured to the very highest standards. An essential component used to protect the hydraulic circuit from excessive pressures building up, they will regulate the amount of hydraulic fluid ensuring maximum output whilst keeping the system functioning safely. Fits Fendt Models 938 Vario MT, 940 Vario MT, 943 Vario MT Fits Massey Ferguson Models MF 5709 S Dyna 4, MF 5709 S Dyna 6, MF 5709 SL