Broken fuel tank/level sensor? Only holds 1/2 gallon?

[Shade Tree]

I have a bobcat 753. Actually I'm borrowing it from my landscaping neighbor. He advised that I have to fill it with fuel every 20 minutes or so. He was right! The problem is that it only holds a couple of quarts. I have to believe there is a bladder or something inside the tank that allows consistant fuel level operation on hillsides and slopes, that is expanded. I hope it is a matter of a loose wire or something like that but I cannot find a detailed drawing of the tank assembly or similar cases in this forum. I would like to fix the problem for my neighbor in return for borrowing the machine. Thanks

 

[Tazza]

I would bet the problem is your pickup line, with age the ruber hardens and just breaks off. I would suspect it has broken off and is not picking up from the bottom of the tank anymore.
I don't know how these tanks are setup, mine has 2 lines that join to the top. One is a return the other is the pickup. Have a look at the lines going into the tank. The other way to confirm this, is to run the loader till it stops, remove the fuel sender and look at the fuel level, if you can still see pleanty of fuel, its definatly the pickup tube.
Its a place to start, let me know how you go.
Good Luck!

 

[Luthor]

I would bet the problem is your pickup line, with age the ruber hardens and just breaks off. I would suspect it has broken off and is not picking up from the bottom of the tank anymore.
I don't know how these tanks are setup, mine has 2 lines that join to the top. One is a return the other is the pickup. Have a look at the lines going into the tank. The other way to confirm this, is to run the loader till it stops, remove the fuel sender and look at the fuel level, if you can still see pleanty of fuel, its definatly the pickup tube.
Its a place to start, let me know how you go.
Good Luck!

I had the same problem with my 743, although it ran for more than 20 minutes before topping up the tank, probably about an hour or so. I found the mesh screen on the end of the pick up hose was almost completely blocked and required a certain head of fuel above it to create enough pressure to allow the fuel to flow. You probably should take the opportunity to remove the tank and clean it completely and maybe replace the mesh screen.

 

[Shade Tree]

I had the same problem with my 743, although it ran for more than 20 minutes before topping up the tank, probably about an hour or so. I found the mesh screen on the end of the pick up hose was almost completely blocked and required a certain head of fuel above it to create enough pressure to allow the fuel to flow. You probably should take the opportunity to remove the tank and clean it completely and maybe replace the mesh screen.

Thanks to everyone for the advise. What I read makes sense and I should be able to correct the problem by checking the pick up system. I noticed that the model number is actually 773 (i first posted 753) but I assuem the advise still appllies. Thanks again!

 

[richard]

Thanks to everyone for the advise. What I read makes sense and I should be able to correct the problem by checking the pick up system. I noticed that the model number is actually 773 (i first posted 753) but I assuem the advise still appllies. Thanks again!

I have a 743B that did the same thing......it turned out to be what Taz says. The pickup tube had broken off and was lying in the bottom of the tank. If yours has done that....make sure you get a replacement tube material that can stay submerged in diesel without degrading. Good luck.