Engine Tier-3 710655- Ch 1 page 13 Fuel system Schematic diagram of the fuel system 1 Feed pump 2 Hand pump 3 EMS control unit 4 Fuel filter 5 Cylinders 6 Fuel tank 7 Return line for excess fuel A Check valve B Gear pump (feed pump) C Safety valve D Pressure relief valve E Drain nipple Overflow valve The purpose of the overflow valve is to limit the pressure in the fuel system and continuously vent it. The overflow valve ensures that the fuel circulates round the system and that there is always fuel in the injection pump for cooling, lubrication and injection. Opening pressure is 0.6 - 0.8 bar . Working pressure is approx. 1 bar .
3 1 Fuel rail 2 Pressure relief valv 3 Fuel filter 4 Feed pump / hand pump 5 Shut-off cock 6 Oil hose water filter - feedpump 7 Water separating prefilter 8 Retur line 9 Drain valve 6 4 8 7 5 9 Supply from tank Retur to tank SHOP MANUAL MT26-31 - 06.2005