Either way the fuel filter of your Citroen C4 Cactus will be on the fuel system. So it will be located between the tank and the carburetor. You can distinguish it thanks to its cylindrical shape with two rods and it is connected by two hoses. Finally, depending on the year, the fuel filter will sometimes be located between the two rear wheels BOSCH Fuel pump. BOSCH Alternator. BOSCH Brake shoe fitting kit. BOSCH Headlight bulb. We offer only high-quality, brand-name car parts at fair prices, such as from the category Fuel filter for CITROËN C4. Car parts from leading manufacturers in OEM quality. It's easy and cheap to order spare parts for CITROËN C4 in our online shop. Citroen C4 and DS4 Online Support with user help forums, FAQ's and Technical guides. 2007 C4 Picasso VTR+ 1.8 Petrol - Fuel filter location Please Quote: Fuel Filter. The fuel filter is contained in the fuel sender assembly inside the left fuel tank. The paper filter element of the fuel filter traps particles in the fuel that may damage the fuel injection system. The fuel filter housing is made to withstand maximum fuel system pressure, exposure to fuel additives, and changes in temperature. Re: C4 Picasso II 1.6 HDi fuel filter drain change. by RichardW » Thu Apr 26, 2018 11:18 am. The filter change is probably every 2-3 years. Draining the water every service - or you could do it more frequently. There should be a drain 'tap' on the top of the filter and a drain pipe underneath somewhere - open the tap and then pump the primer a CrGj.