How Does MEP Aux Fuel System Work?

[CT-Mike]

Now that I have my -803 up and running, I am looking at wiring it up and installing an aux fuel tank. My unit did not come with the aux fuel hose, so I am looking for information on fitting type, etc.

Additionally, do I need a return from the unit to the aux tank, or does the return just go back to the skid mounted tank?

Thanks,

Mike

 

[jimbo913]

Here is the reply I received when I inquired about the fitting.

"

Correct, the adapter is an AN-5 size fitting. I believe you can also use JIC #5 and SAE 5/16" flare tube since AN-5 is an oddball size that is difficult to source."​

in regards to a return fuel line there is none needed. The aux hose just draws from the aux source tank to fill the main tank when needed. There is a float gauge inside the main tank which turns on the auxillary pump.

 

[Korgoth1]

You only need one line, keep the tank higher than your genset fueltank, and remember to place the switch in aux/run position. Lowes or your local hose house will have the fitting you need, Napa with have the fuel line.

 

[jimbo913]

Are you sure the aux tank needs to be higher? I would think that they would be smarter than having a system like that, especially considering trailer mounted gensets.

 

[DieselAddict]

It doesnt need to higher. I ordered the fitting on Amazon and use long fridge icemaker hose for the fuel line. Works like a champ and the materials are diesel safe. And inexpensive.

 

[CT-Mike]

Thanks for the quick replies folks, I greatly appreciate it.

Mike

 

[CT-Mike]

One more question, what type of algaecide/additive to prevent biofouling?

Thanks again.

 

[Korgoth1]

Are you sure the aux tank needs to be higher? I would think that they would be smarter than having a system like that, especially considering trailer mounted gensets.

If it is higher than the tank(on my 004) you do not need the fuel pump, it gravity feeds when the solenoid opens. It just keeps you running when a pump goes down, which has happened to me, when I needed the set most of course.

 

[Korgoth1]

One more question, what type of algaecide/additive to prevent biofouling?

Thanks again.

I have used Bio Kleen, I have also used gasoline when desperate to clean the tanks out. The biggest thing is to watch where you get you fuel from and keep it dry, once you start plugging filters, it's like it never stops, even when you get fresh fuel it's like it stirs up the mess in the bottom of the tanks...

 

[rustystud]

If it is higher than the tank(on my 004) you do not need the fuel pump, it gravity feeds when the solenoid opens. It just keeps you running when a pump goes down, which has happened to me, when I needed the set most of course.

On the MEP-003A you need the pump to work as it will not gravity feed itself. I know, been there bought the "T" shirt.

 

[Korgoth1]

I see, gonna have to keep a spare pump around. Well it would still fill your set tank, keeping you from having to carry diesel should the auxiliary pump go down, but youre sol should the main pump fail, unless you swap the main with aux, theyre the same pump i assume?

 

[rustystud]

I see, gonna have to keep a spare pump around. Well it would still fill your set tank, keeping you from having to carry diesel should the auxiliary pump go down, but youre sol should the main pump fail, unless you swap the main with aux, theyre the same pump i assume?

There are 3 pumps, all identical. Two are the main pumps (one is a back-up) and the third is for the auxiliary fill. You can always use the spare pump in place of the auxiliary pump. I actually took out all my back-up pumps. No need to wear them out. That way when I do need a pump I will have one. You could also just unplug the back-up pump and plug it back in when needed. I just wanted a cleaner look without all the extra fuel hoses.

 

[kloppk]

I believe Korgoth1's MEP-803A only has 2 pumps, the primary fuel transfer pump and the Aux fill pump.

 

[CT-Mike]

Thanks for the info on the fitting jimbo913, I'm talking to the fine folks at Napa now.

 

[CT-Mike]

Anyone out there by chance have a spare aux fuel hose they'd like to sell?

 

[DieselAddict]

The hose linked below is a little smaller than a normal AUX fuel hose. It fits down the filler neck of my F350 a LOT easier. Its also cheap. PVC is no problem with diesel fuel. If you want to spend $2 more you can get the braided SS one. I like seeing the fuel inside the regular one. A NPT to flare fitting is all you need to join them together.

http://www.lowes.com/pd_247025-59288-98514_1z0vil1__?productId=3190913&pl=1&Ntt=ice+maker+supply

 

[rustystud]

I believe Korgoth1's MEP-803A only has 2 pumps, the primary fuel transfer pump and the Aux fill pump.

My bad ! It thought for some reason we where talking about a MEP-003A not a MEP-803A . That's what I get for posting so late at night.

 

[DieselAddict]

Here is what the two hoses look like compared to each other.

 

[TooMuchWork]

Here is what the two hoses look like compared to each other.

Does the ice maker hose have the proper fittings to connect to the Aux fuel inlet or did you have to adapt them?

 

[DieselAddict]

You have to adapt them. I used a 5/16 JIC to 1/4 NPTF then a 1/4 NPTM to 1/4 flare.

The hose in the photo was the first one I made and mistakenly I bought a 3/8 NPTM to 1/4 flare which was wrong but I made it work with a bit of epoxy. The hoses I've made since use the correct fittings with no gluing required.