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Dumb, easy question on fuel system

Amazon-1

Active Member
I assume that the fuel boost pump is cooled by the fuel flowing through it, right?

During testing, I want to check that when the fuel selector valve is off that no fuel leaks by. Will it hurt the pump if it briefly runs with no fuel running through it?

Similarly, I need to calculate how much unusable fuel is in each tank. I planned to do that by running the boost pump with the tanks near empty. When it stops outputting fuel, I will then drain the tanks to see how much unusable fuel is in there.

Will running the pump until "dry" hurt the boost pump?

Thanks!
 
You're describing the way most of us did it, fuel pumps survived :D

From memory and a previous conversation, it's okay for short periods of time just don't run it dry for extended periods of time.
 
I recently installed the fuel pump. Cover plate on top of my pump says "Max Run Dry Time = 60 secs".
 
I assume that the fuel boost pump is cooled by the fuel flowing through it, right?

During testing, I want to check that when the fuel selector valve is off that no fuel leaks by. Will it hurt the pump if it briefly runs with no fuel running through it?

Similarly, I need to calculate how much unusable fuel is in each tank. I planned to do that by running the boost pump with the tanks near empty. When it stops outputting fuel, I will then drain the tanks to see how much unusable fuel is in there.

Will running the pump until "dry" hurt the boost pump?

Thanks!

I have done this and did not hurt my pump. You can expect to get about a half of cup of unused fuel in each tank, this is what I got in both RV but it is a very good thing to do to know for sure.
 
Another way is to run the tank dry with the diaphragm pump and record what it takes to refill. Then you know the usable fuel. I found the tanks aren’t exactly what Van’s say’s they are although I’ve only built one. YMMV. Bob
 
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