Does the primer have to also have the cam pin riding against it?

John, I've been going about things systematically, as best I can anyway. I'm going to push air into the feed line that goes to the pre-screen, if that free's something up I'll drop the tank and clean it out I guess. Otherwise, it looks like I'm dropping the tank and replacing the lines. Can I use like a -8 soft line to replumb? Or do I need to use hard lines? The only thing I'm questioning is how much vacuum this is going to be under. The metal filings were in the prescreen, so they must have come from the fuel tank, not the lift pump, what that tells me? I don't know.

I didn't bother to work on it last night, I was too frustrated, so I went to the bar instead, almost as productive... Tonight I'm going to dig into it more.

 

There's not enough vacuum in the feed line to cause any problem for hose.
Use diesel rated hose from the engine to tank and abandon the stock lines.

 

Thanks Bill, looks like thats what I'm going to be doing... I put the new lift pump in fully, and it did the same thing, ran for 5 minutes, then it died out.

So I'm now looking at some good fuel lines from Jegs, or Summit. Push lock stuff should work I think.

 

One more thing... What size hose should I go with, 3/8" or 1/2"?

 

Don't overthink it, 5/16" for return, 3/8" for supply. The bigger the line is, the harder the pump has to pull....

 

I figured 5/16 for the return, but wasn't sure if 3/8" was enough for the truck to run at high RPM's. I mean, the last Cummins I worked on was a 903 V-8, and I replumbed that whole system with -10AN Lines, because -08AN wasn't big enough.

 

No need for fancy push-locs, keep it simple, hose clamps work just fine.

 

Well I dropped the tank last night, and pulled all the old soft lines, nothing looks horrible, but it could be a crack in the hard line. I replaced everything with Marine Grade B1 hose, and drained the fuel that was in the tank, which had a blue tint to it... and lately I've been running Off-Road which is red since I haven't been driving the truck around, and to try to get it running its a whole lot cheaper than $4.29 a gallon for On-Road fuel.

The "Quick-Disconnects" are anything BUT quick, I had to use a hack saw to cut them open and split them to get them off. Those 90* elbows coming out of the pickup were pretty rotted too, but I gave them a good dose of urethane paint, which should seal up any cracks if there are any. Tonight I just have to connect the hoses, and put the tank back into place, then button everything else up. So about 1-2 hours worth of work.

For you guys who replace lines in the future, either drop the tank (which takes all of 20 minutes. Or lift the bed up, its ridiculous how tight it is working on it from inside the quarter panel.

 

Need, I would probably just connect the tank while it is still on the ground. It would make it much easier to find any problem if there still is one.

Your outlets from the tank were steel? Mine were a still plastic line. Somewhere I have heard there is an updated module, perhaps this is the difference?

In any case, Personally I would get it running before I put that stupid tank back up.........

 

Yeah, thats what I was planning on doing, I just need to go get more fuel since I poured all my old stuff into the waste oil furnace. Ten gallons should do the trick.

Yeah, my outlets were definitely steel, and they were corroded beyond all belief, unlike everything else on my truck, which has zero rust. There was however one 5/16" capped plastic line, that went to the bottom of the pickup, and ended right next to the top of the tank screen. The screen was dirty, but nothing major, I just blew it out with air.

 

Alright, well here's the story:

I did drop the tank to get to everything, as the quick disconnects were not so quick, I had to cut them open with a hacksaw to get them off.

After replacing the lift pump, nothing changed. I went out, bought all new soft fuel hose and ran it from the pre-strainer to the tank pickup. There were 2 steel 90* barbs coming off the pickup, which the "Quick Disconnects" were attatched too, those were incredibly corroded, so I sanded them down best I could, and painted them with some urethane equipment paint I had kicking around, just to make sure they were air tight.

I pulled the screen on the bottom of the pickup assembly, and blew it out with air as there was a little junk in it. Re-assembled that, and connected the fuel hose to the barbs. Then, I put about 2 gallons of fuel in a 5 gallon bucket, and put the pickup in the bucket, just enough fuel to cover the bottom of the pickup assembly. I primed the system, and fired up the truck, it ran perfectly for 20 minutes, so I knew it wasn't the pickup tubes (which are plastic).

I put everything back together and threw it up into the truck, its been running great ever since, so which one of the possible problems it was I have no idea, but I figured while I was in there replace everything since it was out, and it works.

One more thing, the float on the sending unit looked like it had corroded on one side, a good part of it was missing, so I pulled an old brass float out of a Tecumseh carburetor and stuck in on the float arm, works like a charm.

Thanks again for the help fella's.