Chevy Truck Question

[PA_MIKE]

I picked up a 2002 Chevy 3500HD dump at a municipal auction this weekend. It has dual tanks ..... but I can not find the tank switch. I checked the manual and there was nothing in the manual. Any suggestions on this one.

Any opinion on the 8.1 Liter engine?

[agmantoo]

Many big trucks do not have a tank switch. Instead both tanks feed at the same time. There will be a line, metal or hose, connecting the tanks from the bottom outside of the tanks in this design.

[PA_MIKE]

someone else mentioned that but I noticed that if I fill only one tank that it shows full

[Wis Bang]

Originally Posted by PA_MIKE

someone else mentioned that but I noticed that if I fill only one tank that it shows full

Tanks that feed at the same time only have one gauge as the level in each remains relatively the same. Big rigs used to have 'crossover' lines at the bottoms [b/4 regulated away due to road impact fuel spills] and they would equalize the two tanks. Fuel injection pumps more and returns the excess fuel than the old carb systems. Big rigs w/ the old crossover line drew from one tank and returned to the other but since the regulatory changes the draw and return to both, so should your truck so the only put a gauge float in one tank, U just picked the right one to fill...

[agmantoo]

My large truck, an International 4900 series, will exhibit one tank running empty and the other remaining full and will run out of fuel. The cause of this was a mud dobber insect building a mud nest in the rubber vent line on one tank. The fuel tank fill caps do not vent on this vehicle. Yours may not exhibit this problem but if it does then you know where to check now.

[fixer1958]

I worked on one awhile back (GM 1 ton) that had a transfer pump between the two tanks with no tank switch/one guage. It looked like a GM fuel filter/on the left frame rail, with two wires hanging out of it.
I don't recall if it had a filler neck on the back tank or not.

[cfabe]

Not sure about the dual tanks, but a friend has a 2500 suburban with the 8.1L. Very thirsty, gets about 13mpg empty and 9-10 towing his huge travel trailer. Has pretty bad piston slap on cold mornings. But it does do a heck of a job pulling that 40 foot trailer. Uses a fair ammount of oil particularly when towing, GM dealer measures oil consumption in qts/gal of fuel, so a quart per 1000 miles is considered normal.