Bobcat T870 main fuel tank connection leaking which leads to aux tank (happened twice)

[SkidTracks]

Any other owners of Bobcats had to replace main fuel tank because metal insert into plastic of tank started dripping fuel?
Metal insert (has pipe threads) and connects main tank under engine, to auxiliary fuel tank at front of machine.

The leak is hard to locate because you can't see around metal insert of main tank, until engine is removed and tank is removed. Chassis bulkheads block viewing, even with a small bore-scope camera.

Once tank is out and filled with water, small dribble(s) of water will flow out between plastic of tank and metal insert. Over a decade, I have had two tanks fail in exact same area, plastic around metal insert.

Over years, have read about engine compartment fires. Leading to me wondering if subtle leakage could be contributing to fires. Dirt acting like a sponge to hold diesel fuel, and dried leaves, grass, and sticks being low-temperature ignition sources. Even with forestry package, aforementioned debris still gets in, and has to be power-washed out, flood-flushed out, scooped out, and vacuumed out.

 

[brdgbldr]

I was just curious, so I looked at the parts catalog to see what you were talking about.

That looks like a design/engineering flaw. Having that metal tube, inserted in plastic, with a fuel hose attached to it is eventually going to fail. The vibrations from the machine and the weight of the fuel hose are going to work that metal against the plastic until the plastic fails.

You might want to contact Bobcat and see if they came up with a fix for it. I doubt that they did but it might be worth a try.

 

[SkidTracks]

I was just curious, so I looked at the parts catalog to see what you were talking about.

That looks like a design/engineering flaw. Having that metal tube, inserted in plastic, with a fuel hose attached to it is eventually going to fail. The vibrations from the machine and the weight of the fuel hose are going to work that metal against the plastic until the plastic fails.

You might want to contact Bobcat and see if they came up with a fix for it. I doubt that they did but it might be worth a try.

Two pictures might help others to see what is going on with main tank and pipe.


Large rubber fuel line coming from auxiliary tank, going thru bulkhead to main fuel tank located under motor.

Clear tube with metal pipe screws into main tank's metal insert.
Black pipe end would have large rubber fuel tube (pictured above) leading to auxiliary tank.
(Ignore metal insert next to pipe, it goes to different connection)

 

[SkidTracks]

Any other owners of Bobcats had to replace main fuel tank because metal insert into plastic of tank started dripping fuel?
Metal insert (has pipe threads) and connects main tank under engine, to auxiliary fuel tank at front of machine.

The leak is hard to locate because you can't see around metal insert of main tank, until engine is removed and tank is removed. Chassis bulkheads block viewing, even with a small bore-scope camera.

Once tank is out and filled with water, small dribble(s) of water will flow out between plastic of tank and metal insert. Over a decade, I have had two tanks fail in exact same area, plastic around metal insert.

Over years, have read about engine compartment fires. Leading to me wondering if subtle leakage could be contributing to fires. Dirt acting like a sponge to hold diesel fuel, and dried leaves, grass, and sticks being low-temperature ignition sources. Even with forestry package, aforementioned debris still gets in, and has to be power-washed out, flood-flushed out, scooped out, and vacuumed out.

Pictures showing 1st tank leaking water and it's replacement recently leaking water.

Shop put a new O-ring on pipe plug to make sure water wasn't leaking between metal insert and metal plugs threads.