I bought a "Not operationally checked" MEP-803A what can I expect?

[Ray70]

Don't be fooled into thinking the leak is coming from the seal between the metering pump and the block. There is nothing there but motor oil. Your leak is likely a return line that is leaking down from up top and pooling up around the metering pumps and governor / throttle linkage.
Clean it up good and take the top cover off as LITD suggested, so you can get a good look at the injector area. Then with it clean and dry turn S1 to prime / run and watch for leaks while the machine is priming. Look especially at the 3.5mm return lines and all the T-fittings in the return line.
Also look at the rubber lines feeding the metering pumps, as well as the spring clamps where these hoses attach to the pumps.
If no leaks are found start the machine and do the same thing, looking closely at the metering pumps and injector lines.
Often times the wind from the fan and the vibration of the machine make things look different than they really are.

 

[rtrask]

Thats a good leak... only while running or when the set is priming? Have you taken the roof off the set for full access and view?

I did not know there was such a thing as a "good" leak in this situation. I first noticed that there was a bit of a leak before I actually started it while it was in prime mode. And yes following your recommendation I ordered some Viton tubing to replace what is there and pulled the roof off.

Don't be fooled into thinking the leak is coming from the seal between the metering pump and the block. There is nothing there but motor oil. Your leak is likely a return line that is leaking down from up top and pooling up around the metering pumps and governor / throttle linkage.
Clean it up good and take the top cover off as LITD suggested, so you can get a good look at the injector area. Then with it clean and dry turn S1 to prime / run and watch for leaks while the machine is priming. Look especially at the 3.5mm return lines and all the T-fittings in the return line.
Also look at the rubber lines feeding the metering pumps, as well as the spring clamps where these hoses attach to the pumps.
If no leaks are found start the machine and do the same thing, looking closely at the metering pumps and injector lines.
Often times the wind from the fan and the vibration of the machine make things look different than they really are.

My friend who works for Cummins on generators took a look at the video and said essentially the same thing. He said that he thinks it is coming from around the red hoses that connect the pump to the return manifold. From the video you can see that the factory clamps have been replaced with screw type hose clamps. Those clamps seem to be a bit large, and I wonder if the radius of the part with the screw is too large and is allowing the leak. It looks to me like it is leaking from both of the pumps on the front two cylinders. I have tried to source factory clamps, but the prices are ridiculous. One place is selling them at $7 a piece, and $15 shipping, another is selling them at $2 a piece with $30 shipping.

My plan at this point is to remove the return line manifold and inspect those rubber ends for damage. The best case (and I believe most likely) scenario is that all the red hoses are in good shape. If not and the banjo fitting will allow a slight rotation, I will try to trim the same small amount rubber off each hose to get to good rubber. If that proves to be impossible, a new return manifold seems to be in the $400 range. After I have the return manifold sorted out, I will try some more appropriately sized hose clamps to connect to the injector pumps, and connect the rest up with new Viton tubing. When I get the fuel return line back in working order, I will follow the procedure you outlined above.

Look especially at the 3.5mm return lines

I have read in other places in this forum that it is 3.5 mm hose, but I have not found such a thing. I cut out a small chunk of the return line and as best I can tell it is 1/8" or 3.175 MM inside diameter hose, and that is what I ordered. I am pretty confident that it will stretch, but do you have a link to 3.5 mm tubing? The OEM military hose does not specify the actual dimensions.

 

[Zed254]

Stick with the screw hose clamps: they are WAY better than the OEM clamp. My 802 had a weeping leak so I pulled the manifold and installed new hose with the OEM type clamps. Still had a small leak. Drove me nuts with the fan blowing stuff all around. I finally changed out the OEM clamp to the correct sized screw hose clamp and that corrected the leak.....until the 2nd one started leaking, too. Changed that out and all has been good. My problem was the tight space at the engine and the needle nose pliers I was using. I think I sprung the clamps. I used the OEM clamp on the manifold and those 2 are still holding fine.

 

[Ray70]

So yes, if you go on ebay you can find tons of 3.5mm diesel fuel line. It's very common on Mercedes Benz etc. mostly made by Continental. rubber hose with a braided cloth covering. That said, you can also use plain rubber vacuum hose from the parts store. You want 5/32" . However, Viton is a much better material as the vacuum hose will also break down over time.
For your fuel rail, don't buy a new one! take a dremel tool with a cut off wheel and slit the side of the metal crimp ferrules and pry them off. Underneath is a hose barb. Just get 1/4" rubber fuel hose and replace the rubber lines. You can use either hose clamps , spring clamps or even zip ties to hold the hose on. The 1/4" line fits good and snug and won't leak even with no clamps.... not that I would suggest doing that....

 

[Daybreak]

Howdy,

MEP-80x Fuel Return Line

Howdy, The MEP-8xx series of generator all use diesel fuel return lines. After sometimes sitting with no fuel, or heat cold, no-use etc... they start to fail. The main issue is the lines start weeping fuel. NSN 4720-01-483-6467 part N20353.5 HOSE, NONMETALLIC Name Value...

www.steelsoldiers.com

 

[Guyfang]

If you want peace of mind. Just change all the fuel lines, A lot of these set have had not just diesel run through them, but JP4. JP4 is a good fuel, and running it makes sense for the Army, but it will do nasty things to fuel systems.

 

[rtrask]

[/QUOTE]

So yes, if you go on ebay you can find tons of 3.5mm diesel fuel line. It's very common on Mercedes Benz etc. mostly made by Continental. rubber hose with a braided cloth covering. That said, you can also use plain rubber vacuum hose from the parts store. You want 5/32" . However, Viton is a much better material as the vacuum hose will also break down over time.

My search was specifically for Viton 3.5 mm which did not yield good results. I was perhaps a bit to broad in my statement that I had not found such a thing. A better question to have asked is since I have already ordered the 1/8" Viton will I run into any issues in using it, or should I return it?

For your fuel rail, don't buy a new one! take a dremel tool with a cut off wheel and slit the side of the metal crimp ferrules and pry them off. Underneath is a hose barb. Just get 1/4" rubber fuel hose and replace the rubber lines. You can use either hose clamps , spring clamps or even zip ties to hold the hose on. The 1/4" line fits good and snug and won't leak even with no clamps.... not that I would suggest doing that....

Thanks this is good advice. I pulled the return manifold off yesterday, and found that the clamps that on the 1/4 inch lines were not installed correctly. First the screw clamps were too big for the radius of the hose which deformed the hose and probably was the main cause of the leak. (see picture) Second the clamps were put on on top of the barb, which is not recommended for a single barb fitting. I replaced the clamps with thinner smaller diameter clamps and placed then behind the barb on the fitting. I need to clean up the mess from previous runs to do a better job of verifying that there are no leaks, but it currently looks good.

One of the hoses that was not previously leaking showed weather checking on the end of the inner section of the hose. I expect that someday I will need to follow the procedure that Ray70 described above, but I will probably leave it until it becomes an issue.

 

[Ray70]

My only thoughts on the 1/8" line is that it may be too small to fit over the plastic barbed fittings. You might be ok if the hose id soft and flexible enough, but if it's too small you may split the hose down the side trying to force it on. I've never tried anything that small, but you won't know until you try it.

For the weather checked hose on the metering pump, probably should at least have the parts on hand to fix it because you know when it's gonna start leaking right? It probably won't be on a nice warm sunny day while the power is on!

 

[maniatopoulosg]

Looking back at the inspection pictures now, I think pic 21 & 38 show the pintle pin exposed, sorry we didn't catch that.
I purchased an LTT with 2- 802s back in October from Chambersburg, Zed254's keen eyesight spotted the pin exposed in the inspection pictures of mine . I had it shipped to me, loading it at the yard, they busted off the landing jack mount with their forklift. It's only riveted on the bottom of linette. I found the rivets above align with below so I cut them off and ran bolts all the way through the tongue to the jack mount. View attachment 791261

I need one of those


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[rtrask]

I need one of those


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you need one of what?

 

[rtrask]

I pulled the old return line off, and built a new one from the Viton hose I bought. I replaced it, cleaned all the diesel from the engine and inside the cover. When I fired it up it I could see no leaks. I think that the problems with the leaks are resolved. In the course of installing the return line I discovered that I have the well nut problem. After that is resolved, and the issue with the oil pressure gauge I think it will be ready to put into service. So all in all I think my not operationally checked generator was a good purchase.