Can a clean looking filter still be restricting fuel?

[Conflict]

• Truck died while driving. No fuel pressure. Changed filter. Fuel shooting out of the schrader valve and truck runs fine. I can blow air through the filter easily. Open the filter and it looks clean. Could it still have been restricting totally? Every time I turned the key the pump was humming. Suggestions? Change the pump just in case? Look in the tank for crud? Tank seems plastic. Were they all plastic for 2wd manual 2001 B2500's? I'm tempted to remove everything and put in 2 smaller tanks with their own pumps? I don't like not knowing the cause.

 

[cbxer55]

Guess it's just like a fuse looking good, but being bad. Or a spark plug.

I recently changed my fuel filter, hadn't done so in probably 10 years. Could not blow through it.

What gets me is why they even need the secondary filter. There is a sock on the pump to keep it from getting plugged up. Despite that, the inline filter still gets plugged up. My three motorcycles have the pump filter only, no inline filter to be found.

Things That Make You Go Hmmmm.................................

At the same time as the filter, had a really dirty MAF. Spray wouldn't remove the brown stuff that was on the upwind side of the wires. Had to use a q-tip and alcohol to get whatever it was off. Felt kind of sticky. Don't know how that got there. New filter and clean MAF fixed it right up. Previously, the MAF was not working. If you pull the plug while the engine is warm and running, and it keeps running, the MAF is not working. Cleaned it and it works now.

 

[pjtoledo]

so it's running now?
just looking for why it died?
try looking at the connector and wires attached to the inertia cut-off-switch.
if your pump is 25 years old I wouldn't feel bad about replacing it.

 

[JoshT]

What gets me is why they even need the secondary filter. There is a sock on the pump to keep it from getting plugged up. Despite that, the inline filter still gets plugged up. My three motorcycles have the pump filter only, no inline filter to be found.

Fuel pumps work better at pushing fuel than at pulling it, you want as little restriction as possible before the pump. Large micron sock filter in the tank stops large debris that would damage the pump, but still permits a large amount of flow with little restriction. Small micron filter inline stops contamints that may clog or damage the injectors, but would pass by the pump harmlessly. Some modern vehicles only have a single filter in the tank and it's never intended to last the life of the vehicle, of course we all know how those intentions go.

For the motorcycles, I would assume that it has a lot to do with size. Due to the small engines and small size of the fuel system, they probably require a lot less fuel flow. They probably do fine pulling through a much finer filter. Smaller fuel batches, typically much more involved owners with more careful maintenance, easier to access the filters for replacement. All speculation.