Fuel filter change - Please help

[Thunder]

Hi all, possible noob question so please bear with me.

I am going to be changing my fuel filters on a 96 DT466. I know I need to fill them with diesel before installing the new filters. And also that they need priming. I have located the priming pumps without issue (they are pretty obvious). But have been trying to locate the valves to release the air as I have seen in many videos.

I have attached images of both fuel filters here. 2 angles of the water separator and 1 of the other filter.





The only thing I can find on the separator is this bolt that I circled. Should it be loosened to remove air during the priming process?




The only thing I can find on this one is the potential valve circled here. I have already tried pressing it as it is with no movement. So I am guessing I need to loosen it up before being able to press it? If this is the valve?

[s2mikon]

Go up to the injection pump and look for a bleeder screw there. DO NOT pour fuel down the center of the fuel filter. Plug the center hole and pour around it filling the outside of the element.

[Booyah45828]

If you have priming pump(s), don't fill the filters, It's not needed and pre-filling them will only introduce contaminants into the fuel system. OEM's have found that most people prefilling filters do it wrong and introduce contaminants, and none of them recommend it be done anymore.

Your water separator is a pretty generic head. The bolt you circled is the one you remove. It should have an o-ring seal underneath, so make sure that isn't disintegrated before re-installing.

The 2nd filter head you've got the air port circled as well, I believe it's a needle and seat type unit, so it only needs loosed, not removed.

Remove both filters. Install new water separator and remove plug on head. Pump until fuel is present at plug and then reinstall plug. Pump some more until fuel appears at 2nd filter head, then install 2nd filter, loosen 2nd screw, and pump 2nd priming bulb until fuel appears at screw. Tighten screw, start bus, and hold at high idle. Shut bus down, look for/clean leaks, clean hands, job done

[Thunder]

Thank you both lots for the very helpful info!