OK, so I got my new fuel pump, 3 blue hoses, 1 black hose, and banjo bolt washers in. Original issue was a significant fuel leak into the valley. Truck fired right up and runs fine, mileage seems to be up. I figured I might have been losing half a gallon an hour.

The good news... the valley is bone dry. Possible bad news- I have fluid on the ground. Dripping off the right side fender liner, from the back corner inside the engine bay. The insulation on the right side fender and liner is pretty much soaked. The fluid is way too clean for engine oil, but a little too viscous for fresh diesel. Consistency is like new-from-the-bottle engine oil. And I can't find any sign of a leak around the engine... valve cover, head gasket, front and rear fuel fittings to the head, oil pan. The dipstick tube shows signs of old, sticky seepage at the pan fitting but no fresh fluid, so I figure it's OK.

But I'm optimistic that I'm OK. I did spill quite a bit of fuel when I partially drained the fuel bowl from the water valve, and more when I pulled the lines and pump. So I'm figuring that some of that fuel ended up in the insulation- either running down the block or blown off the block/frame crossmember/running gear while driving, and is finally seeping out of the insulation. And since it's been hot, I figure the fuel is slowly evaporating and looking less like diesel.

Does this sound reasonable? Or should I be checking for a fresh leak other than the valley?

Changing the hoses, pump, and banjo bolt washers wasn't too bad. I'm really glad I finally got a top creeper- it's a major help when you're *** in the air and head down in the engine bay.

I did not pull the turbo for the banjo bolt. Mine is not a California truck, so I can get the box end of a 32 mm combo wrench on the banjo bolt with the turbo on. A ratcheting head would be nice, and flex would also help. The usual "Z"-shaped double-box-end wrenches have too much offset. I'm glad I have and thin long fingers- big hands or short fingers would be a problem getting the bolt, fitting, and washers stacked up and started without removing the turbo.

The fuel pump came out with no hassle once the banjo bolt was off. I did cut the hoses, then removed the pieces and clamps once everything was out of the truck. I had to cut one or two hose pieces off the fittings. The hoses were brittle, swelled, and a bit cracked, but I don' think those were my leak. Installation wasn't bad. However, do plan how you will orient the hose clamps so you can get at the heads to tighten them. And the bottom blue hose... you probably want to put that on the fuel bowl and tighten down the clamp while the bowl is loose. That one is the most awkward to get at.

For tools, the only non-standard items are the top creeper and 32 mm combo wrench (Harbor Freight has that size in a fairly cheap set). After that, common sockets, extensions, pickup tool, a U-joint, small prybar, kitty litter (fuel from lines, pump, bowl...), paper towels, and lots of hand cleaner.

 

The possibility that still is the residue of the fuel/oil leak is a good one, so take your time. Another possibility are the BIG bolts in the back part of the rails see pic.
This is a bump for you.

 

Good picture. Wish my engine were that bright, makes for much better visibility in the gloom of the engine bay.

I felt around the fuel line fitting on the rear of the block and only got dry grime, but I couldn't quite get my fingers under the fuel line fitting. I didn't see anything coming off the back of the block or the transmission. If the big black oil plug above the fuel line was leaking, I should have had oil on my fingers, but I'll check that area specifically.

 

You need a mirror from the upper part (under hood) and also you could check there for under the truck with some patience and a little difficulty.