Help replacing fuel check valve on 3406e

If it is the valve I believe you are looking for, it is on the bottom of the fuel block mounted behind the air compressor. If I remember correctly a 15/15 or 1 inch wrench will remove it. Ensure you have a new oring on the new check valve. Do not reuse the old oring.

 

what problems would a bad check valve cause

 

Hard starting after it sits for a period, fuel bleeds back to the tank.

 

thanks for the info just checking to see if this was part of my problem but mine has no power and runs like its starving for fuel change injectors , fuel pump and filters it runs like filters are blocked after 15 minutes of drive time with low boost

 

How old is the truck? Old fuel lines can/will collapse starving engine for fuel.

 

its a 2000 model w900 with 2ws 3406e

 

Yes- fuel lines will collapse. The inner lining separates and pinches off the fuel flow. Good fuel lines have three layers. The inner layer separates when it gets old- and, collapses from suction.

Sometimes the fuel line connections loosen and they suck air. The most common problem is fuel cutoff valves leaking air. If you have valves that cutoff the fuel from each tank, they leak after a few years. The material used to seal the valve dries up and shrinks, letting air in under a vacuum.

If you have those fuel cutoff valves and never use them you can just replace them with fittings that have no cutoff valve in them. Easiest way to solve that problem. Fuel lines are easy to replace, and if you don't like cutoff valves or don't want them, just replace the whole length of fuel line and leave the cutoff valves out.

There's a small chance it's the fuel tank vent tubes that's causing the problem, in high dust situations the vent tubes can clog- just remove the fuel tank caps and blow the vent tubes out with compressed air.