I've previously mentioned having problems with the rear tank on my truck.

This is the sort of thing it does-

Yesterday I got in the truck and started it, and switched to the rear tank. I drove it down to my dad's house (not far, maybe half a mile) and did some stuff down there for a bit. Started it up, drove back up the road a little ways, let it sit and idle for a few minutes while I did something at my grandma's. While I was leaving there, I noticed it was idling a little rough, but otherwise ran fine. I drove it up to our house and shut it off.

Came back out a little later to drive back down to my grandma's garage (was gonna work on swapping out the leaky front tank). Started the truck, it ran for 2 seconds, and shut off. I cranked and cranked it it sounded like it had no fuel whatsoever. I switched it back to the front tank and spent the next 15-20 minutes purging air from the system and getting fuel back into the engine

I finally got it restarted and drove down there. While I was working on swapping out the rear tank, I checked out the rear fuel lines. I noticed the hardlines are REALLY corroded where they run along the frame- I wonder if air is getting in there somehow and causing these issues?

 

Air can leak in where fuel won't leak out when not under pressure. I'd replace the lines if they look really bad.

If you have less that about 1/3 tank, the pickup tube or return line inside the tank is probably messed up. On mine, it will run fine until it runes out at about 1/4 tank on the gauge. However, if I park it facing even slightly uphill on the rear tank for a few hours with less than 1/3 tank, it will suck air...

 

Well, I'll probably just run it off the front tank anyway....being that it's 19 gallons, with the price of diesel, I won't want to fill both tanks. And I just realized I'd have to drop the front tank again to reaplace the hardlines running to the rear...ugh.

The rear tank has a little over 1/4 tank in it, by the way. Front tank had about 3 gallons in it when I dropped it. Runs fine off the front tank, but very finnicky on the rear tank.

 

My vote would be for the broken pickup tube in the rear tank.

 

I have had the rust letting air in problem. Found my rust under hold down clip . Cut that section out and replaced with fuel hose. Haven't had problems in 5 years.

 

I vote for rusty fuel lines.---besides you can do the work without droping the tank!

 

ghunt, That is one of those things you "fix it all". Look over everything and replace all the lines if you need to. It is like a busted brake hose or tube. If one goes replace them all while you are at it.

 

The lines to the rear tank should be plastic.

Since you had about 1/4 tank, my dollar is on the pickup tube being cracked or the bottom dropped off.

 

Dave, on mine they are definitely steel where they run along the frame.

PO told me he had the fuel lines replaced at one point (when he had the rear tank replaced) but who knows how long ago that was.