Air bubbles in fuel line

[sshier]

I have a problem thats got me pulling my hair out. Air bubbles are coming out of the fuel tank on my hood loader. I have pulled up the fuel tank pickup and resealed all the joints and inspected it for holes and cracks. And im still getting air bubbles. Im thinking that the fuel is sloshing around and aerorating my question is what can i do to prevent- fix this it never started happening until i started using a fuel stabilizer same maker as diesel 911 in white bottle. Tank vent is clear tell me what you think thanks for the help

[lumberjack48]

I had this happen on my S8, i put a new fuel line from the tank to the pump, same thing. I was also pulling my hair out, i took the line off, but this time i took the elbow fitting out of the fuel tank. I looked in it, there it was, a little stick caught in the elbow causing the fuel to gravitate. Put it back together, it ran better then ever, that  stick cost me about 5,000.00, in lost  time.

[thenorthman]

I know its not the same machine, but on my skidder the pickup tube comes in from the top of the tank, the tube itself was rusted and rotted inside the tank, so with an absolutely full tank it would run fine, get 1 gallon low and she'd start sucking air.  Ended up moving the pick up line to the drain plug.  Other then getting crud stuck in an elbow once its worked pretty good so far, I get water in the filter pretty easily now, but that's why they made water seperators...

But to find this problem I went through the whole God's danged fuel line 3 or 4 times checking every fitting and replacing every hose, finally I ran it off a jerry can for a few hours, the problem went away, thats how I decided it was the tube inside the tank.  By the way if you try the jerry can thing remember to plumb in the return line...

I also replaced the supply pump, which came in handy 2 weeks ago cause the old one saved my bacon when the new one went out...

[lumberjack48]

When i had this problem i took 3/8 fuel line, put a nipple on the pump so i could hook the fuel line up. Then a coke can cut in two, this fit over the filler spout on the tank. Then i made a hole in the bottom of the coke can so that the 3/8 fuel line just if though it. The skidder ran perfect with this set up, so i new there was something wrong with the main fuel line.

[sshier]

Thanks for some ideas im thinking ill drop a hose in the tank
and rebuild pickup and see if that helps has anyone had problems with that fuel additive by diesel 911 in the white bottle what about off road fuel vs ultra low sulfer fuel as far as cavitating

[mikeb1079]

good to hear from ya lj 48!!!   8) 8)

sorry to hijack thread   

[Bobus2003]

Thanks for some ideas im thinking ill drop a hose in the tank
and rebuild pickup and see if that helps has anyone had problems with that fuel additive by diesel 911 in the white bottle what about off road fuel vs ultra low sulfer fuel as far as cavitating

Power Service is a pretty good brand, I've personally never had any problems with it. I run cetane boost (silver bottle) year round in my rigs.

[hardtailjohn]

I run Power Service most the time too, in my trucks, pickup and equipment.  The one thing we did have happen that sounds just about like what you've got going on, is a couple years ago, all the rubber lined fuel lines on our crusher started to deteriorate on the inside lining. It wasn't easy to see or find, but we were getting air in the lines just like you're talking, and once I changed to Nylon lines, everything was back to good. Maybe something to check. 
John

[snowstorm]

air brake tubing works good for fuel lines. it is tuff stuff

[sshier]

Well i pulled the return line fitting and put a piece of
5/16 fuel line to get the return into the fuel instead of aerorating the fuel .
It was sort of like a fish tank aerorater and since the pickup and return lines are very close it was just circulating the air bubbles.

[barbender]

Power Service is good stuff, and it sho' 'nuff don't make air bubbles ;D

[marcusthgault]

I once had air bubbles showing in the bit of clear pipe that feeds the injector pump.
After changing the fuel filter, i.e fitting a brand new out of the box good brand name item.
Checked absolutly everything, cut the ends back on the various suspect "rubber" hoses, removed the rear seats to access the fuel tank and pickup and dismantled and reassembled it.
Smeared grease on every joint I could find, etc etc.
All to no avail.
Until I, in desperation, it must be said, I simply changed the fuel filter for another new one.
Problem solved.
Obviously a minute crack or leak in an upper seam or spigot on the new fuel filter, and I could not find where despite pressuring the removed filter with compressed air.