Oil & Fuel Fuel Leak

Climber · Oct 28, 2003

Two weekends ago, I changed the transmission oil on my B7300HSD. When everything was put back together, the hydraulics did not work. Kubota suspected an air lock and referred me to my dealer. My dealer suggested I blow compressed air into the case to force the oil up to the pump. That did not work. It was an air lock, and I cleared it after trying the suggestion of another forum member. You can read all the details here:
http://www.tractorbynet.com/forums/showflat.php?Cat=&Board=genoperating&Number=332894&page=0&view=collapsed&sb=5&o=186&fpart=1&vc=1&PHPSESSID=

Unfortunatly, when I woke up the following morning, there was a puddle of diesel fuel on the garage floor. The leak appears to be coming from the underside of the fuel tank, but it's an area I can't seem to reach, or even see very well. It's buried behind the dash. I'm suspecting the compressed air trick blew out one or more gaskets or lines. My questions are:

1) What's the best way to access that compartment? Do I have to remove the dash? How hard is that?

2) Do you have any more concrete ideas as to what might have happened?

I am really dejected, as a seemingly simple Preventive maintenance service has turned into a nightmare.

Thanks for any and all suggestions.

--Chris

Bird · Oct 28, 2003

( puddle of diesel fuel on the garage floor )

I had that happen once (or was it twice? /forums/images/graemlins/confused.gif). Anyway, I had filled the fuel tank when it was cool, then the warmer weather caused expansion and it had run out the overflow/vent tube. Is that a possibility with yours?

And on my B7100, the "plastic" fuel tank was held on with two metal straps around it. There were strips of rubber between the metal and plastic to prevent chaffing, but my fuel tank developed a very small crack in the bottom right under one of those straps and I had a little leak there. Another possibility?

Personally, I don't see how applying air pressure to the hydraulic reservoir would put pressure into the fuel tank. /forums/images/graemlins/confused.gif

Junkman · Oct 28, 2003

Are you sure that the machine is a Kubota?????? not some machine that has a lot of yellow on it like a lemon that someone painted orange and passed off as a Kubota?????? LOL.....

Climber · Oct 28, 2003

Bird,

Overflow is a distinct possibility. I did fill the tractor up, last thing before I put it away. However, the overflow pipe would be an open-ended tube pointed down to the floor, right? My leak appears to be coming from the underside of the fueld tank, pretty high up. It's definitely not coming from anything that looks like an overflow tube.

 ( Personally, I don't see how applying air pressure to the hydraulic reservoir would put pressure into the fuel tank ) 

Me neither, but I thought the 2 events might be related.

I will draw down the fuel level tonight, and see if it still leaks.

--Chris

skent · Oct 28, 2003

Chris, seems you are finding the same stuff I found with my B7300. If you remove the insulation blanket from the tank. you will see a place on the tank where the injector return line sends excess fuel back to the tank. It goes through the side of the tank wall close to the top and is sealed with a rubber gromet. If you fill your tank to the brim, you will get some seepage of fuel around this gromet. I went so far as to replace the gromet, but the next year it would seep again. It's best to fill the tank only to the point that you see it's about 5 or 6 inches from the top. I suspect that when you tried raising the rear of your tractor, you got some seepage and the insulation blanket soaked it and will continue to drip for a while.

Climber · Oct 28, 2003

Oh, it's a Kubota alright. It always worked great until I tried to maintain it. This is the last time I EVER do any maintenance on the thing! /forums/images/graemlins/wink.gif

art · Oct 28, 2003

Your air pressure didn't have anything to do with the problem you are talking about now. They are two totally seperate systems.

RichNJKubota · Oct 28, 2003

Don't give up!!
Just learn from your mistakes.
Rich

Climber · Oct 29, 2003

Steve,

I'm guessing you hit the nail right on the head. I used up some of the fuel last night, and the leaking seemed much less this morning. I'll be sure not to fill it quite so high in the future.

Thanks for the help. I really appreciate it!

--Chris