753C Fuel Fill problem

[Irocrcr]

I have an older 753C series with around 2000hrs on it. About the last year or so I have started having troubles when filling the machine with fuel, either out of a pump at the gas station when I have it on the trailer, or out of a 5 gallon can when on a job site. As you start to fuel it, after putting in a gallon or so it acts like it is full and the fuel starts pouring out of the fill neck, even though it still should be able to take another 10-12 gallons. If you stop and wait a minute you can put in another gallon or so. Takes up to 20 minutes sometimes to fill the tank with 12 gallons of fuel. I have it in the garage now with the cab up and I see two lines going to the fuel filler. The large one has to be for fuel and then there is a smaller one that I am guessing is a vent of some sort, but I can't see where the smaller hose goes to. Is there a possibility that the smaller hose got plugged somehow and thats why it won't take fuel? Any suggestions on how to fix it? Thanks in advance..

 

[Irocrcr]

Just a thought, would it be advisable to blow compressed air down the vent tube to clear it of any obsructions, or would I risk wrecking something if I did that?

 

[Tazza]

Just a thought, would it be advisable to blow compressed air down the vent tube to clear it of any obsructions, or would I risk wrecking something if I did that?

I would look at the filling neck under the cab. There should be a large hose, that's for the fuel to the tank, there should also be a smaller nipple with a hose that links from the tank to the filling neck, this is a breather, it could be blocked or crushed.
Now, the next possibility is a filter. If you remove the lower end of the filling tube where it connects to the fuel tank, there should be a filter screen that sits inside the tank. If it's plugged, it will back up.