Tank Draw Issue/Question
 

Last night (running from Savannah to Houston) - i decided it was safe to run my tanks to the Texas Line (825 miles), even if i was only getting 8mpg (which ive never seen), I'd have plenty of range (2 x 60g tanks).

Feeling comfortable w/ our coach now (over 12k miles since last year).

Interestingly enough one tank (driver side) took close to 55 gallons, while the passenger side tank barely took 36 gallons (of 60).

the generator ran about 2 hours (1gph maximum, and the generator was NOT loaded).

MY QUESTION:

what happens if i were to run ONE tank Dry....would i be sucking air, will the truck DIE ?

If the tank the truck engine is pulling fuel from runs dry, yes it will die. "Usually" the truck will be pulling out of the passenger side tank (low side of the road). The engine return line "should" be in the tank that it is pulling from. The same goes for the generator. If the return lines are plumbed to the right side and the engine/generator are pulling frome the left tank,you could get the situation you described or the line running between the tanks (equalizer line) is either to small or has some blockage. You really don't want to run it out of fuel as they can sometimes be a real pain to get restarted. MMM

UNDERSTOOD & Agreed !
i have / use 2 other diesels - one mechanical ('84 300cd), the other "electronic" ('04 f350 6.0L)

Yes, tanks should readily equalize.

The other answer is to have a selector to run out of one or the other, gauges on both, and then manage the use.

Don't the tanks always equalize when the engine is running? I thought that was how they work anyhow. I'm pretty sure my tanks keep about the same level judging by when I'm filling up anyhow. I don't think there is a crossover line at the low point on my tanks though. I think there is some way they circulate the fuel between the two to keep them equal.

My FLD 120 has at least a 1" line between tanks. They should equalized pretty fast.

newer trucks have a suction and return line through both tanks about a 1/4 way up from bottom of tanks. a pickup tube goes down inside tank to about 1" off bottom. returning fuel goes through a valve with a ball in it. ball rolls back and forth depending on which return line has the most pressure. about like blowing through a straw. if ball sticks or freezes it will return all the fuel to one tank. that tank will over flow and other will run out of fuel killing engine. so your generator could lower that tank but when you start driving it should equalize again. if one tank is mounted higher it can cause a problem also.