There are two types of filter, Siemens have all fixed in a Plastic cylinder , Bocsh use exchange filters made of paper.
Look for a black round box with same pipes conected to.
There ars 2 bolts to move on this box, 3 inch below, screw of the Topp and clean the box ( pull out the fuel in a tin, juse some to clean, and pull back the rest through a Coffee filter )
This is for Siemens system
Handyman, April 2008
