DIY Fuel Filter Drain And Replacement Mercedes-Benz Sprinter Oct 18, 2016Drain Fuel Filter DIY Quick Fix. Because this is a known problem with diesel engines, the fuel filter on the Sprinter can be drained using nothing more than a screwdriver, a pliers, and some patience. The fuel filter is located underneath the air filter cartridge, right on the top of the engine. You will have to remove all the clips to get it out. Online Owner's Manual [In depth | Practical advice | Engine] Draining the fuel filter. On vehicles with a diesel engine, it is necessary to drain the fuel filter if the indicator lamp lights up. When the indicator lamp lights up, drain the fuel filter with water separator immediately. Otherwise, the engine may be damaged. Close drain plug as soon as approximately 0.2 litres of liquid have been collected.