MEP 803a Fuel Drain?

[Surf]

I have recently purchased a trailer mounted MEP-803a. The fuel drain was not attached and looks to have been knocked off. It is still attached via the retention chain but the hole is not plugged with the drain. Looks like the "grommet" or "plug" was not installed straight just off the looks of it and it was probably knocked off easily. I did a lot of research, read all the manuals, including the parts manual and searched numerous threads here and on other forums.

I have not had much luck other than, this is indeed a weak spot and not an uncommon problem. I have also heard of fixes involving various mesh or fill type of "patchwork" on the hole. My questions are;

1 - Is the drain valve simply a press fit for retention in the gas tank drain hole? Cannot find a retaining nut on the inside of the tank. Parts manual does not appear to show one either, so perhaps the drain neck and petcock is a press fit assembly?

2 - To me the Tech manual is really unclear on the "grommet" or "plug", but rather shows what looks to be the corresponding part as part number 38 and lists it as a "nut". (38 XDOZZ XB XBOZZ 07707 A3816 .NUT 2 2) Part number is A3816. This looks to be the "grommet"?

3 - Searched for the part number replacement with no luck. Anyone can point me in the right direction, it would be much appreciated.

4 - Anyone have pics or advise on how to plug the hole? I have thought about tapping the hole and plugging it, maybe a petrol based thread sealant and washer? Even thought about a helicoil set up. Any thoughts?

I have attached a couple of photos and any and all advice on solving the issue is appreciated! Open to part for replacement / repair to just plugging the hole.

 

[Humpy]

If you get Marinetex Gray, I believe it will seal up just fine. It is designed for repairing hulls and fuel tanks at sea. I have used it on plastic and steel tanks and works fine.

 

[Surf]

If you get Marinetex Gray, I believe it will seal up just fine. It is designed for repairing hulls and fuel tanks at sea. I have used it on plastic and steel tanks and works fine.

Thanks Humpy, I appreciate the reply. I have considered this method and have not ruled it out.

 

[kloppk]

The A3816 appears to be a basic Well Nut.
http://www.bylerrivet.com/products/item-details.aspx?pid=633

You might be able to unscrew the old valve from old well nut. If it no too deformed you may be able to insert it back into the tank and then screw the valve back it expanding the well nut.
If the well nut is too distorted you can readily buy a new one.

 

[Surf]

The A316 appears to be a basic Well Nut.
http://www.bylerrivet.com/products/item-details.aspx?pid=633

You might be able to unscrew the old valve from old well nut. If it no too deformed you may be able to insert it back into the tank and then screw the valve back it expanding the well nut.
If the well nut is too distorted you can readily buy a new one.

Well nut! Thanks! Old nut is a no go, probably why it came off. Trying to locate a new one, awesome thanks!

 

[m-35tom]

yes it is a well nut. forget about using sealants etc, they are not the proper way to repair it. make sure the well nut is the correct material for diesel.

 

[Surf]

yes it is a well nut. forget about using sealants etc, they are not the proper way to repair it. make sure the well nut is the correct material for diesel.

Thanks Tom, I agree that a bonding material was not the way to go. I was able to locate the correct petrol well nut and it is buttoned up. Thanks for the help!

 

[Humpy]

Now that I have seen a pic of a well nut I agree the Marinetex would not be the option. Up until now I have survived 68 years without ever seeing a well nut haha

 

[khestee]

Anyone know what size machine screw will fit the well nut we're talking about here. I have the same issue, the petcock and nipple extension pipe is missing from my 803A fuel tank too.

 

[CBR Metalworks]

I bought a new wellnut yesterday for mine, actually bought 5 of them, not sure why I bought extras... 3/8-16 is the thread I think. You are best off replacing the wellnut before you put fuel in the tank.

 

[kloppk]

The thread size and pitch for the A3816 well nut is 3/8-16 thread size

 

[metalman50]

Just bought the correct wellnut for my gen with the same issue on eBay its listed in the military generator parts section and works perfect.

 

[Surf]

This is not uncommon that the entire part is off the genset. When they Demil these and drain the tanks, they just knock off the entire fixture. Mine was still connected to the unit via the retention chain. Many are just completely missing. When looking closely how these are attached it is readily apparent that this is not even close to the most durable design and a point of common failure, even when not intentionally knocked off the unit. If it is just sitting, probably not an issue, but if trailered and moved around often be aware of the potential. I can see how you can re-use the well nut but it isn't the worst idea to have spares. On the other hand, retro fitting a threaded drain plug with a petrol rated nylon washer wouldn't be a bad idea either.

 

[khestee]

Thanks for the info. I was hoping I didn't have to take the tank out, but gotta do what I gotta do.

 

[metalman50]

I took the filler neck off (it was a challenge with the top bolts, I cut a section of the side panel and slid my hand with a wrench and got the bolts off) and used a modified plier to hold the wellnut while my wife tightened the fitting. The original was in one of the
book compartments. I just cut enough for the tank cover to conceal the piece I cut out. Putting it on I tapped the nut to the wrench. I tested the tank and all is well, except the Generator wont crank, but I'm working on it with the of others on this site. Installing the nuts I taped them to the wrench, I also thought of removing the tank, this was done in about 45 minutes.

 

[khestee]

Just bought the correct wellnut for my gen with the same issue on eBay its listed in the military generator parts section and works perfect.

Thanks for the info. Still looking on ebay for one. No luck so far. How did you search for it?

 

[khestee]

I bought a new wellnut yesterday for mine, actually bought 5 of them, not sure why I bought extras... 3/8-16 is the thread I think. You are best off replacing the wellnut before you put fuel in the tank.

Thanks CBR, glad to see someone close by who can answer some of my questions.

 

[m-35tom]

the one i saw on eb was crazy expensive

 

[metalman50]

The one on Ebay is listed in the military generator parts section, I first went to MEP-803A and then saw the section in the top part of the page the found the wellnut. Its listed as a fuel pressure adapter for a 60K. The numbers match exactly. I offered a lower price and he took it. hope this helps.

 

[Greenoner]

I have recently purchased a trailer mounted MEP-803a. The fuel drain was not attached and looks to have been knocked off. It is still attached via the retention chain but the hole is not plugged with the drain. Looks like the "grommet" or "plug" was not installed straight just off the looks of it and it was probably knocked off easily. I did a lot of research, read all the manuals, including the parts manual and searched numerous threads here and on other forums.

I have not had much luck other than, this is indeed a weak spot and not an uncommon problem. I have also heard of fixes involving various mesh or fill type of "patchwork" on the hole. My questions are;

1 - Is the drain valve simply a press fit for retention in the gas tank drain hole? Cannot find a retaining nut on the inside of the tank. Parts manual does not appear to show one either, so perhaps the drain neck and petcock is a press fit assembly?

2 - To me the Tech manual is really unclear on the "grommet" or "plug", but rather shows what looks to be the corresponding part as part number 38 and lists it as a "nut". (38 XDOZZ XB XBOZZ 07707 A3816 .NUT 2 2) Part number is A3816. This looks to be the "grommet"?

3 - Searched for the part number replacement with no luck. Anyone can point me in the right direction, it would be much appreciated.

4 - Anyone have pics or advise on how to plug the hole? I have thought about tapping the hole and plugging it, maybe a petrol based thread sealant and washer? Even thought about a helicoil set up. Any thoughts?

I have attached a couple of photos and any and all advice on solving the issue is appreciated! Open to part for replacement / repair to just plugging the hole.

Surf,

Did you have any luck finding the correct part for your 803 fuel drain? I am in the same boat, everything I read said I had to order a well nut, but the one I was sent is way to big for the bottom drain. Plus I cant seem to find the petcock either. I need both the well nut/grommet and petcock. Thanks.