First want to thank DB staff and members for all the information here, has helped fix a few problems I have had. Now I have one that has not been directly addressed before, at least the symptoms. Over the months, it appears that my fuel sender in sticking further up it's traveling limits. Other posts indicate that others have issues with it just going to empty. I'll explain;
In July, I stupidly ignored the fuel gauge and idiot light saying I was out of fuel. I finnally decided I fuel up, pulled into the station, put $100 in and would not start when time to leave. WTF?? Other patrons were more than happy to push me out of the way. Got a tow home and thanks to DB, purged the fuel system and got it running again. I swore I'd never do that again. End of August, Cruising along on I-90, the pedal went dead and as did the engine, with 1/4 tank of fuel. WTF??? A tow home, purged air and 28 gals of fuel, I was up running again. Last month, I made a delivery, came out and darn thing would not start. Fuel gauge around 3/8. Tow home, Purge, and refill (28 gals). I had read that some were having problems at 1/4 tank so I put piece of tape at the 3/8 mark to remind me to fill up before then. This purging routine is getting old. Last week went all the way to Olympia for business and back the long way, watching gauge the whole time. When I get home, the gauge is reading around 3/4 and I think to myself, wow what great milage, but that can't be right. I go fill up, 23 gallons, a far cry from being 3/4 full.
So my question is what should I be looking at, the Sender, gauge or something else. Need to burn off a whole tank of fuel before I drop the tank.
Bill

 

I'm wonder about your sending unit&pick up also. Maybe draw tube has a hole in it? I would chec everything from the tank to the lift pump&beyond,hope fully injecter pump did not get messed up when the lift pump went bad.I've seen the floatstick to the inside of the fuel tank because the sending unit being turned wrong way upon reinstallation Hope this helps

 

I'm leaning towards sender, but will have to wait until I burn this tank of fuel up. Hopefully fuel price will go way down by then.
Don't think it's the draw tube as I still manage to empty the tank, the gauge just tell me that. Gonna be one of them people that use mileage to determine when to fill up.

 

Do you have a deck, or anything mounted in your box? If now, it is so much easier to pull your box off to access the fuel sender, compared to dropping the tank. 6 bolts, tail light wiring, and 3 screws for the fill neck. Once it is off, you can pull the sender out.

 

If you're lucky its just dirt in the pivot pin not allowing the float to move. Most likely the problem is that the plastic pivot arm is loose allowing the arm to wobble and bind. You can take the tank module out and modify it but that is no real guaruntee that it will fix it. Or you can get a vulcan modified module (Modified fuel module) Here is a couple pics of a modified float.

 

Aren't these 35 gallon tanks? so if your running out & putting in 28 gallons that leaves I'm thinking 3-4 inches of diesel in the bottom thats not getting picked up

 

Thanks all. Who would have thought it easier to remove the bed rather than dropping the tank. I'm still open for debate on that. I figure the float must be gummed up or being held in some fashion, why else would it not indicate or warn when down to 5 gals and then progressively "stick" further up. If I could bang on it I would. Thanks again.
Bill