Draining sediment from the fuel filter (VW Passat B4)

Remove the holders of the check valve 1 (Fig. 3-49) of the fuel filter. Remove the valves from the filter without disconnecting the fuel lines from the valve. Remove the fuel filter from the bracket. Unscrew the drain plug (shown in the inset in the figure) and drain the water and sediment from the fuel filter, then tighten the drain plug. Replace the fuel filter and filter check valve. Remove air from the fuel system.