I just got through with changing my fuel pump today. THe Bosch replacement is a godsend - that turbine pump is *quiet* and certainly develops the right pressure and flow rates. In a nutshell:
WHen you drop the tank, try to get it as dry as possible. I did this with a limping fuel pump by using the pressure relief valve on the fuel pressure gage and bypassing fuel flow as the engine was idling to a huge gas tank.
When you drop all of the body armor off, you may have to use WD-40 or some other penetrating lube to free up the long 15mm bolt that holds the rear strap to the truck. I had to hit both that one, and the 15mm nut for the front strap.
Loosening and removing your filler neck bolts just inside the gas flap will give you more play room to line up and take off/reinstall the filler and vent lines at the back of the tank.
USE a set of flare nut wrenches and a back-wrench on the crimped fuel lines to remove the main fuel line and return to the tank. Feel atround on the top of the tank closer to the outside of the truck around where the sending unit's retaining collar is. You'll fine a fuel vapor relief valve with a pressed on fuel tube. Remove this tube in addition to the grounding strap and disconnect the wire harness for the sending unit before you completely remove the 15mm bolt to drop the rear of the tank.
Loosen, but do not completely remove the front 15mm nut to drop the tank down a good 1.5-2 inches and reach around the front of it through the plastic body armor wrapped around it. Near the front, outside area you're going to find another vapor purge valve. Remove the tube from the valve or the metal riser tube that meets up here. I broke the front one, not knowing it was there and had to go to the dealer to get the replacement valve. Thew new valve went in easy, but breaking the crud and grit around the old one was a PITA.
*CLEAN* the top of your tank once it is down. For some god awful reason there was like 10 pounds of kitty-litter like gravel, rocks and compacted mud and road grit solidified like terra cotta clay all atop of my tank. I could not even see the collar from the retainer that holds the sending unit in the tank through the grime. WD-40, brushes and plenty of towels are your friend.
I do not know if they ship from the factory like this, but some yo-yo gooped the top of the sending unit shut with what looked like JB Weld. Took me *HOURS* of clean-up and chipping at this crap to get all shiny looking metal and finally get the ring to rotate after pounding the lock tabs flat with a screwdriver tip and taps with a hammer.
Remove the retaining ring carefully out from around the sending unit's pipes and wire harness. Once free, the sending unit simply comes up and out of the tank. As you withdraw it from the tank, be mindful of the bends in the pipes and the sending unit float. Mine came out with a nice, gentle, up, to the side, and 180 degree twist in one fluid motion to get the works out of the tank in one go.
The old fuel pump literally pops out of place. Use the fresh grommet for the pump base in the Bosh kit to replace the bayonet-fitted OEM pad. Remove the pulsator unit, it's not needed with a turbine pump. Replace the pulsator unit with the small length of rubber fuel line in the Bosch kit. Insert the new motor into it's rubber sleeve until the base metal of the body projects slightly from the bottom of the pump from under that sleeve. Use the new pressure clamps that came in the kit to secure the pump and fuel line that replaces the pulsator to the sending unit assembly. Once tight, give them a good squeeze with horizontal pliers. THis crimps them *solid* into place. Use the upgraded wire harness in the kit to complete the electrical conection from the pump motor to the old wire harness' clip where the old motor hooked up. It will look a little long and gangly when done, but nylon ties will tidy things up. Double check that the sending unit's pipes are true and straight, and that the pump sits SQUARELY in the grommet bore, the grommet itself pressed snugly against the lower metal clamp that retains it to the sender. Pop your new strainer sock onto the end of the pump in the same manner that the old one was oriented. It will press onto the end of the pump with a firm pressure and a small click. My replacement was slightly oversized from the stock, OEM part. But it is still more than manageable to set properly back into the tank if you angle it in, and reverse the motions I described above.... in this case, one side of the filter goes in after letting the float into the tank first. Rotate to the other side gently to poke the other side of the filter into the thank. Rotate 180 degrees as you lower it, watching the angle of the tubes. The tangs at the tp of the sending Unit will not let you put it in any other way. Now about that tank gasket - which you do before you drop the sending unit...
Clean, clean, and clean again the lip of the tank where the sending unit goes. DIscard the old tank seal and use the new one in your kit. If you get the same kit I did, posted earlier; you will find two gaskets. The smaller one is what you want. I lubed the gasket with a thin layer of plain old oil to aid assembly and assure that it would not be pinched/displaced when I tap the locking collar's ring in the opposite direction to seal the tank again. Once the locking collar rotates back into place, pry up on the ears of the tabs you tapped flat earlier to lock it securely into place.
The rest of the job is pretty much the reversal of dragging the tank down. However, you'll have to be either a midget or have vice-grips for hands to finesse the filler neck tube and vent line back together. It took me a few tries and the gentle persuation with the tip of a very thin phillips screwdriver, but I got them back into place. Once the tank was bolted snug, but not totally tight within the straps, the tubes mated with the hoses perfectly. I then re-installed the the three 7mm bolts inside the filler neck to help hold that just where I wanted everything and finished tightening up the straps.
Good luck, and I hope that you all glean something from my paltry contribution. I unfortunately did not take photographs...I was not about to go and get my expensive digital cam get all covered in grease and grit.
The real thrill now:
On a truck that was sitting on a battery for two weeks (It was disconnected before I began work), I hooked up my fuel pressure gage. I dumped about 10 gallons of gas in the tank for a little over half a tank. I hooked that battery up, and turned the key to "RUN" but didn't start it. THe fuel pressure gague *immediately* jumped up to 62 PSI. I took the key out, and it dropped....too quickly. I thought I goofed something up. So I am looking for pooling gas, sniffing for it, nothing. Must have just been a ton of air in the system rushing past the fuel regulator. I repeated the KOEO two more times. At the third time I turned the key, she held at 64 PSI, and maintained that pressure unassisted for at least 30 minutes as I picked up, counted tools and got everything out from under the truck and dropped it off the jackstands.
I merely touched the key and she lit up hard and strong, not even half a crank. I was getting used to having to wiggle the key back and forth a few times only to get a weak and sputtering start and a surging, bumpy idle. *ROCK SOLID* smooth idle and instant, lunging starts are the norm again.
Cleaned up and went for a test drive.... I came back home before I was cited for exhibitionism or a speeding ticket. She's got power like I never felt before, I guess fuel flow is where it belongs again. She does not struggle to make power, and can easily navigate the hills on the highway without dropping out of overdrive like she was doing in the weeks leading up to the pump failure. My baby's BACK!