I'm about to change my fuel filer.The question is do I fill the filter up before I install it or install it empty and prime the heck out of it?

They prime easy

so ther is no need to fill it

No don't fill it. Just change the filter, pump the priming pump with the bleeder screw closed until you can't pump it any more, then open the screw and pump a little bit until fuel shoots out. Close the screw and start the truck. That is how I do it and it starts as usual without any problems.

If you fill it, you're putting unfiltered diesel into your engine.

Very easy to prime and is the way to go.

If you fill it, you're putting unfiltered diesel into your engine.

Very easy to prime and is the way to go.
X2 you don't want unfiltered diesel in the engine. Besides who wants to get diesel in a gas can so you can fill it up with unfiltered diesel?

Prime it, that is why you have a primer pump.
With new diesels you don't want unfiltered fuel going to the injectors.

:exactly:...

There is also a drain on the bottom of the filter to get the fuel out before you take the filter off. Helps to do this so your not spilling fuel all over the place.

There is also a drain on the bottom of the filter to get the fuel out before you take the filter off. Helps to do this so your not spilling fuel all over the place.

This "drain" is the Water in Filter (WIF) sensor. It's not intended to be removed until after the fuel filter is off the truck.

The fuel is about an inch or so from the top of the filter so you have a bit of leeway before any spillage. If you're concerned with spillage, just wrap a bag around the filter after you've cracked it loose with a filter wrench. Then carefully pour the diesel from the filter back into the tank (via a funnel).

"some"people fill their filter with injector cleaner