R3039 Fuel Tank Leak

[Gary Fowler]

My new tank arrived UPS today. I'm impressed with the support from my dealer and LS. The new tank is shaped just like the old one so that same corner is still molded in. There is one difference from the old to the new. The front wall on my old tank (next to the seat) had caved in a bit so that it was kind of convex shaped. The new one is nice and straight. And it goes without saying, the corner isn't cracked on the new tank.

Gary, thanks for the advice. I'm going to run the fuel out of my old one then switch. After the switch, I'll look at patching the old one.

It will work, just rough it as much as you can so the JBWeld has something rough to hold on to and acetone it till it is oil free and dry

 

[Harleydog]

I know this is an old thread but my R3039 is in the shop now for the same thing, tank leaking.

 

[bruceatlam]

My replacement tank is still doing just fine ---- but, I'm still a little nervous about it. I'm really interested in what your dealer may have to say about just "why this leak develops"??? Is yours leaking at that same seam????

I'm bothered by what happens to my plastic tank as I operate the tractor. The tank runs under a slight vacuum. As a result, as I use fuel, the front side of the tank caves in toward the back of the tank. It's not just a little bit --- it's really dramatic. Doesn't seem right to me. I've developed the habit of opening the fuel cap every 1/2 hour or so to equalize the pressure in the tank. After I finish using the tractor, I fill up the tank and close up the cap. As it sits there, the front side of the tank expands back out to where it originally started and I top off the tank ------

I'm really curious to see what your dealer might say --------------

 

[Gary Fowler]

Sounds like you have something stopped up, either a vented fuel cap is not working or the vent line has dirt dauber plugged up the line. There shouldn't be a vacuum on the tank at all.

 

[bruceatlam]

As I've been told, most/all diesel fuel systems operate under a small vacuum to minimize foaming. The cap on the R3039 has a little spring loaded poppet in it to relieve an over pressure ---- nothing about it does anything to prevent an "over vacuum" ---- if such a thing exists.

And, yes, it's definitely a vacuum ---- you can hear the vacuum release as you open the cap and you can see the front wall of the fuel tank relax a little.

I do not know if it's true that all systems operate under a small vacuum??? I don't know if this system is operating under a higher vacuum than it should???? If there's a device in the system to relieve the vacuum at some point, I don't know where/what it is????

 

[Gary Fowler]

I have 3 diesel tractors (JD, LS and Kubota) and not a one of them has a vacuum on the tank. Brother in law has a NH and no vacuum on that either. You need to check out what is causing the tank to suck in and fix it. Likely not the cause of the factory defect that caused the seam to leak though.
I would hope that LS replaces your tank like they did mine when the embedded nuts that held on a weed shield cause the tank to leak at all four nuts. They not only replaced the tank but redesigned it to remove the nuts and made a new support for the shield. I had fixed mine with JB weld and made a solid steel brush guard for the whole tank before I got the replacement about 2 years ago and the big box with the tank and guards is still in my shop waiting on the JB weld repair to start leaking.

 

[Harleydog]

Not sure where its leaking yet but they are going to do the JB weld fix and return it back to me for a spare. I will let you know more when I find out. I only have about 57 hours on it but this is the only real issue I have had. It's been a great tractor.

 

[bruceatlam]

Thanks --- the JB weld "fix" does work.

Let me know what they say about "why" it happened in the first place?? Ask them the question about vacuum ---- does the system operate at a small vacuum or not?? If not, how does air enter the system to replace the fuel that gets burned??? That little poppet in the fuel cap only relieves an over pressure as far as I can figure.

 

[clan de boye]

I'm bothered by what happens to my plastic tank as I operate the tractor. The tank runs under a slight vacuum. As a result, as I use fuel, the front side of the tank caves in toward the back of the tank. It's not just a little bit --- it's really dramatic. Doesn't seem right to me. I've developed the habit of opening the fuel cap every 1/2 hour or so to equalize the pressure in the tank. After I finish using the tractor, I fill up the tank and close up the cap. As it sits there, the front side of the tank expands back out to where it originally started and I top off the tank ------

I'm really curious to see what your dealer might say --------------

I have that exact issue with mine also. It has caused the tractor to stall from fuel starvation and would only start again after the vacum was broken by removing the fuel cap. I also open the cap to remove the vacum while working and would like a solution to the issue. If you find the answer I'd appreciate it if you would post the solution. thanks

 

[bruceatlam]

I have that exact issue with mine also. It has caused the tractor to stall from fuel starvation and would only start again after the vacum was broken by removing the fuel cap. I also open the cap to remove the vacum while working and would like a solution to the issue. If you find the answer I'd appreciate it if you would post the solution. thanks

I'll post anything that I learn here ---

I think that I'm convinced that these tractor fuel systems should operate at atmospheric pressure --- neither under pressure or vacuum. So, that said, the device in our fuel system that allows the pressure to equalize to atmospheric is the fuel cap. There is a plastic disk inside the fuel cap with a little spring loaded rubber poppet in the middle of it. The poppet is solid ---. I can see how mine would relieve pressure from inside the tank but I can't see how it lets air into the tank to relieve the vacuum. In the "olden days" fuel caps had a little bleed hole in them. That makes sense to me.

So, entirely on my own at no one's direction, I've drilled a small bleed hole in the middle of that rubber poppet. Unfortunately, I don't have any extended run time on the horizon until mid October/early November. So I won't be able to observe any success or failure until then. Hopefully, I haven't created a new problem. But, if I have ---- I'll just buy a new cap assembly.