Fuel tanks on a peterbilt

Hello everyone,

I just signed up to this forum even though I been sucking information from here for over 10 years. I recently started having an inconvenience that I can’t put my head around. I bought a new truck(to me) a 2006 Peterbilt 379 with a c15. Now everything on the truck works as I like it to be, but a couple of weeks ago my passenger side tank went empty while my driver side wall 90% full. The truck came with a tank that sucks fuel from the top and one that sucks fuel from the bottom(I figured someone crushed a tank and replaced one of them before me) the driver side only has a return valve to and no valve on the pick up line. My passenger side side has a valve in each line. So I had to get a manual pump and lift some fuel into the other one to make it to a fuel isle(I was literally in sigh of the truck stop when it died). I cleaned the breathers on both tanks and I figured that would be the end of it. Well, a week later it sucked the driver side empty and filled up the passenger side. So I having valves on that tank just closed it off and finished the week. Then I was sent to a crappy job site and a pile of dirt slightly opened the valve I closed. And it sucked air again and I was on the side of the road pumping and priming again. So what I’m doing in checking the fuel levels every 100 miles if so and playing with the return valves of the driver side to sort of manually equalizing the fuel levels. Because it’ll either suck empty one tank or just force fuel out of the caps. Any help on how to control this without having to check fuel levels every other hour? Thanks.

PS it doesn’t equalize the tanks after I shut the truck off over night. Someone told me it should do that by gravity, but it doesn’t.

 

I go off roads daily. Someone already suggested this but if I was going to put a line on the bottom of the top draw tank, I would already make it draw from the bottom as well. I had a 1987 Pete that had a line down there and it would break almost monthly going off the road. I’m just going to replace that tank with a bottom draw and see if that fixes it.

my stepfather was telling me to put a tube on the return line that would go to the bottom of the tanks and that way the weight of the tank with the most fuel would make the returning fuel go to the most empty tank. I don’t know if that will work. But I might give it a try, I just just looking if someone had similar issues in the past and found a solution. Thanks you anyways

 

@FLHT i didn’t see your reply. The truck is “new to me”, the line are old but the they seem to be fine. The fuel block is just there. I didn’t take it apart and it look like just a T to me

 

I’ll probably do that. Just one more item to the long list of stuff.

I’m driving locally right now because I want to see what leg she limps from.

fuel lines were already in the back of the list. Sounds like I’ll bump them up in the priority list.

 

I think the passenger side tank go crushed and replaced with a bottom draw one, my guess, the driver side has a huge patch on the back. I’m eventually going to replace it. It runs good now, but I want to have more funds before I start looking into cosmetics.