MEP-804A Fuel Fill Neck

[loosegravel]

Good morning. I'm learning more about these wonderful machines all of the time. In the past 4 years or so I've had a variety of the 8XX series of generators go through my hands now. I recently brought home (2) of the MEP-804A units on trailers from Hermiston, Oregon. With these (2) units I've now had about (6) of the 15kw units. I always appreciate the help and support that I get on this forum.

I have always replaced the fuel well nuts on these generators when I get them home. It's an easy upgrade using the 3/4" bulkhead fittings with 1/4" NPT threads, backed up with steel washers and neoprene washers. But much to my dismay I've had fuel leaks on a couple of these 15kw machines even after the fuel well nut upgrades. I discovered that the fuel leaks only occur when I'm pouring fuel into the main on-board tanks. Ultimately, I removed the fill neck assemblies and discovered that the angled rubber sleave which connects the upper fill neck to the tank is rotten. In looking at TM 9-6115-343-24P, page #98, figure #13, item #15, I can see NSN 4720-01-392-0319, part #88-22068.

Oshkosh Equipment seems to be out of them. I could run a parts request quote through WB Parts, but I was first wondering if any of you have been able to source them a different way or come up with a sufficient substitute like you did for the fuel well nuts?

Thanks as always!
Jeff

 

[Evvy Fesler]

I can’t measure mine or look it up at the moment, but thought something like this of the correct inside diameter.

Gates 23924 Fuel Fill Hose-3' Length, Inner Diameter 1 1/2" https://a.co/d/dNxNeve

 

[loosegravel]

I can’t measure mine or look it up at the moment, but thought something like this of the correct inside diameter.

Gates 23924 Fuel Fill Hose-3' Length, Inner Diameter 1 1/2" https://a.co/d/dNxNeve

Thanks, I guess I should have provided pictures and dimensions. I’m not at home right now, but it’s more like 3” diameter on the bottom where it connects to the tank and about 4” diameter where it connects to the fuel fill neck above. It also has about a 30 degree angle on it. I’ll shoot some pictures later!

 

[Evvy Fesler]

Thanks, I guess I should have provided pictures and dimensions. I’m not at home right now, but it’s more like 3” diameter on the bottom where it connects to the tank and about 4” diameter where it connects to the fuel fill neck above. It also has about a 30 degree angle on it. I’ll shoot some pictures later!

Yes, I know it’s quite large, as is mine. It was just an idea to get people thinking. Someone here will either have one or another idea.

 

[Daybreak]

Since they all use the same fuel cap. Someone figured out for the MEP-803A a while back.
803 fuel filler rubber gasket | SteelSoldiers

 

[loosegravel]

Since they all use the same fuel cap. Someone figured out for the MEP-803A a while back.
803 fuel filler rubber gasket | SteelSoldiers

Good thread from a couple of years ago. Thanks for sharing it!

 

[loosegravel]

I found one on eBay for $85. A little steep for a hose, but it is a pre-formed hose. A wire wound hose like was previously suggested is out of the question. It measures 4.250” ID at the top and 3.00” ID at the bottom and about a 30 degree bend.

 

[loosegravel]

I found a place on-line a few years ago that will custom make hoses with a different inlet and outlet size. But, as Daybreak pointed out, material is everything. The one on the right was one that I had made for an LS swap project I was working on. And it’s silicone. Not good for this application

 

[loosegravel]

I got the exact part from eBay on Friday. Installed it and that unit is good to go. I sure wish these fuel fill necks were specked with captured nuts. They're called "riv-nuts" in the trucking industry. They're installed with a rivet-like tool and now there's no more fuss when taking something apart or putting it back together again. I usually buy the 10-32 size riv-nuts from Fastenal by the 100's. I'm out so I had to suffer on this unit by using a piece of tape to hold the nut in an open end 3/8" wrench and then hold it up under the whole, then screw in the 10-32 machine screw.