Incorrect fuel reading tank shows empty, but can only pump 50 gal

hi guys, my truck has 2 tanks. It says 120 gallons on one and 100 gallons on the other. If my fuel gauge shows near empty, when i fuel up i am only able to put about 50-60 gallons on each side. This sounds crazy right. When i drive i go about 750 mile and it would go back to empty. Has anyone had this issue? Shouldnt i be getting like 1400 miles with both tanks full? Truck is a 2012 cascadia, dd15 engine.

 

What's the make of your truck

 

i have never known or driven any truck made to have accurate fuel gauges.

i would "stick" the tanks, and using a chart get a value of what the fuel levels were in each tank. after that, i'd not bother no more, and fuel up accordingly.

you could bring this up to the shop, they may be able to remove the sending unit (float) and make an adjustment, or they may replace them.

 

If it’s a Freightliner it is typical! I’ve had 2 freightliners and the fuel gauge does exactly what you describe from time to time.

 

Find someone with a texa computer you can change the fuel tanks buy plugging into the 9 pin

 

Both my trucks did the same thing, show the yellow/red near empty light on the gauge but only took 100 gallons to fill up (200 gallon capacity).

 

Thats a bit of good news for me, ive always thought that the tanks still had fuel in it but was too afraid to keep going. Its possible that one of the sensors on 1 tank is broken? I will definitely have it looked into further.

 

Most (all?) trucks only have one fuel level sensor. As long as both tanks stay level it doesn't matter.

What I've seen a lot of is shops don't ever replace with the correct sensor. They will put one for a 100 gallin tank in a 120 for example.

 

So what did u do? Just watch ur miles? Did u keep driving even with the light on and the gauge on E? That just feels scary going down a grade.

 

Yes I just reset my GPS mileage to zero when I fill up and I know the max distance I can go before MT.