This is why it's a good idea to replace the fuel lines in a vintage vehicle. This filter plugged with rust and sediment after we replaced the gas tank in the wife's '50s car. The inside of fuel lines will rust just like any other steel component exposed to air and moisture. If your car has ever sat and the fuel lines drained, the inside of the lines could rust. You'd think this would eventually clear itself out, but consider the surface area of the inside of a fuel line that's 20 feet long-that's a lot of area covered by rust as fine as talcum powder. This filter has been cleaned and replaced numerous times.