Fuel Leak

[ncsawyer]

One thing that drives me crazy about my new mill is the leaking fuel cap.  Every time I tow it somewhere it blows diesel fuel out all over everything.  I've even tried cutting my own piece of cork gasket to fit in the fuel cap, thinking that the original rubber one wasn't making a good seal.  Even with the new gasket, it still leaks fuel out of the cap.  My old mill didn't have this problem.   Has anyone else experienced the same problem?

[Jim_Rogers]

On my gas tank cap there is a vent knob in the middle. We were told to screw it in while driving around and sometimes people forget to unscrew it when they start sawing. This can end up making a vacuum in the tank.
Does your cap have a vent screw/knob?

Jim Rogers

[Ox]

Sounds like the wind blowing past is siphoning the fuel out of the vent in the cap as it's sloshing around in the tank.  An empty tank (not advised on a diesel because of possible loss of prime problems) would be one cure.  Another would be a piece of inner tube, heavy plastic or cork gasket material cut to fit the tank neck perfectly and then screw the cap down tight to give a perfect seal all the way across the filler hole.  Heck, wax paper folded over a couple times to make it thick would probably work fine.  Diesel will probably deteriorate the rubber after a while.  Just don't forget to take it off before starting or you might collapse your tank a little!  Either that or the engine won't run for long.  Careful taking the cap off if it gets warm after you put the seal in, it'll give a nice puff I imagine from expansion. 

[boscojmb]

The first time I towed my mill I had a diesel mess.
Now I just run it down below 1/2 tank before I move it.

[ncsawyer]

I wish my cap had the little screw in vent knob.  That's how my old one was and I never had any problem.  I may search around and see if I can find one with a screw in vent knob.  I like the idea of using something to seal off the entire opening, but the inside of the cap is not flat at all.  It's got a big peak in the middle for the vent that would make sealing off the entire opening difficult.

[Ox]

It would be sealed around the lip of the filler neck.  Just instead of using a flat gasket or flat sealing ring it like is probably what's on it now it would be one continuous "washer" of sorts.  It would make no difference if you had a flat or domed cap.  I hope I explained that OK...  Basically it would seal off the whole neck with the cap twisted on and pushing down all around the lip of the threaded neck and the the solid piece of round "whatever you use" keeps it air and liquid tight like a splash guard of sorts.

[Brucer]

The cap on my (relatively) new gas tank is different from the old vented style. The cap screws down tight but there appears to be some kind of internal bypass to let the tank vent around the seal at the neck of the filler spout.

The cap also has a plastic cord that runs down into the tank, which prevents you from losing or dropping the cap. It also interferes with a complete gasket that would seal the entire filler spout.

[terrifictimbersllc]

Right, my older green tank has a cap with a screw on it, and the newer yellow one has a cap with no screw.  The newer one vents somehow out of the cap and this can allow diesel to get out too.

[Nomad]

     How about sticking a plastic sandwich bag over it and holding it there with a big rubber band?

[kelLOGg]

I don't have a diesel engine but I do have a diesel lube tank with a cast iron cap to cover the fill port. I drilled a hole in the cap for ventilation and stuffed it with felt to keep dust out. Diesel has never sloshed out and it flows freely via gravity when sawing. Just my $0.02 idea.
Bob

[willmyers0169]

like nomad said, simply lay the sandwich bag over the hole and screw the cap down, works just fine.  I would also think a cork gasket would easily be dissolved when in contact with diesel fuel, not sure on that one.

[ncsawyer]

Wood-Mizer seemed to think that I had a defective fuel cap so they sent me a new one just like the old one.  Hopefully it won't leak like the old one.

[Ox]

I like the ziplock bag idea.  Same principle as what I was trying to say but much simpler and quicker!  Bags are cheap and replaceable.  But hopefully the new cap will be the solution.