I changed the oil and fuel filter in my 91 12v a few weeks back. This maintenance is performed every 6 months due to speedometer not working and miles don't register. Noticed the top of my old fuel filter looked rusty. Cut the filter in half and there seems to be a fair amount of rust inside.
The filter is obviously doing its job. The rust feels like old foam that instantly crumbles when you touch it. Truck runs fine.
What has me puzzled is the truck has a plastic fuel tank, yet lots of rust has been trapped in the filter. I fill up at the same station, same pump, same everything, about 95% of the time. Same for when I had my TDI Jetta and for my 05
CR. Neither of those vehicles ever showed rust in the fuel filter.
Only thing I can conclude is the truck had rusty fuel pumped into the tank in its previous life. Which was usually red off-road diesel from a gravity fed tank with spin on filter inline, from what I know.