MEP-802/803 fuel return improvements

[DieselAddict]

For the 802 you can't replace the fuel nipple on the injectors. Its soft tubing or nothing. Nylon isn't an option for the truly pain in the ass part of the fuel system. For other parts, sure. Not for the area around the injectors though which is the most fun to replace part.

I'm in the middle of replacing all the tubing on one right now. I'm putting in tygon and we will see how it holds up.

 

[Daybreak]

Just so you all understand, rubber based hoses will ALL fail after time. If you go to the DOT nylon hoses you will never have to worry again.

Howdy,
What product? from where?

The CRP N203535-5 CONTITECH Diesel Hose is the new bio-diesel capable hose. In the VW, Mercedes world, it is also known as the yellow stripe diesel fuel return hose. Yes, rubber fails over time. But, non-use hurts rubber also.

Either way, I now have all new fuel return lines on my units. I guess I won't be worrying about that for a long time now.

 

[rustystud]

Howdy,
What product? from where?

The CRP N203535-5 CONTITECH Diesel Hose is the new bio-diesel capable hose. In the VW, Mercedes world, it is also known as the yellow stripe diesel fuel return hose. Yes, rubber fails over time. But, non-use hurts rubber also.

Either way, I now have all new fuel return lines on my units. I guess I won't be worrying about that for a long time now.

The thing about DOT nylon hose is it can run any fuel. Gasoline, diesel, bio-diesel, kerosene, it doesn't matter. My one IHC (gas engine) truck has been running DOT hose for over 35 years now and no problems. We run this hose on all of our busses, have as long as I have been there which is 23 years now. When I worked at IHC trucks in the 1970's all the trucks ran DOT nylon hose. All the semi-trucks I have seen still run this hose. It is an industry standard.

 

[Daybreak]

Howdy,
I am talking about the fuel return line.
Very low pressure braided fuel return line. The 3.5mm hose fits nicely on the tees and connectors and stays tight.

 

[m-35tom]

i don't know how you get 3.5mm hose on, i use 4mm and it is a very tight fit. the units i replace it on already had 4mm hose from new, obviously never replaced. also the tees are the same size as drip irrigation hose parts which are 4mm so replacements are as close as walmart.

 

[AOR]

I found this thread searching for MEP-803a fuel lines. I have been doing some research and my 1995 model that had a tier 2 reset in 2010 has the older style fuel line on it that has braised on and crimped to the 1/4 SAE fuel hoses that run from each injector to the metal return line.
It's a really bad design. My hoses are dated 2009 and are very dry rotted. I looked in the parts manual and the line and hoses are sold together as an assembly and I have not been able to locate one. So I am hoping that there is a barbed fitting under the crimped on sheath. Has anyone had any experience with this? I already know it's going to open up a can of worms and I have thought of several ways to reengineer it but I was hoping to be able to use existing barbs and add clamps if possible.

 

[m-35tom]

it is very low pressure, i doubt you even need clamps with the correct size hose

 

[AOR]

I am concerned with what is under the sheath that is either brazed or welded to the metal fuel line. Hopefully there is something there to attach the hose to and not made into the sheath

 

[m-35tom]

hose is never clamped from the outside, it always has an internal pipe

 

[AOR]

I have replaced the rubber fuel hoses and posting this so if others are in the same situation they will have the answer. The reason I was worried was because someone I know is still currently in the military and has been working on these for 17 years. He said the newer design they had to make flares on the ends of the pipe after they cut off the sheathing

Here is what I found. The 1/4" fuel hose is rated for 400 psi and has woven material under the dry rotted outer rubber portion of the hose. I do not think it was going to leak anytime soon but the outer portion of the hose peeled of with my fingers. The pressures here are very low
The sheath is not brazed or welded to the steel portion of the fuel line. The paint made it look as if it were. I used a dremel tool with a small cutting wheel to slit the brass sheath on 2 sides then they easily peeled off. I slipped off the rubber hose and put on standard 1/4" fuel hose along with new pinch hose clamps
I also sanded the steel line to bare metal to inspect for pitting and repainted it and the end result looks as if it came this way and it's very easy to service now. Why they used 400 psi rated hose with the crimped on sheathing is a mystery to me. I guess overkill for possible life and death situations is the answer.

 

[rustystud]

I have replaced the rubber fuel hoses and posting this so if others are in the same situation they will have the answer. The reason I was worried was because someone I know is still currently in the military and has been working on these for 17 years. He said the newer design they had to make flares on the ends of the pipe after they cut off the sheathing

Here is what I found. The 1/4" fuel hose is rated for 400 psi and has woven material under the dry rotted outer rubber portion of the hose. I do not think it was going to leak anytime soon but the outer portion of the hose peeled of with my fingers. The pressures here are very low
The sheath is not brazed or welded to the steel portion of the fuel line. The paint made it look as if it were. I used a dremel tool with a small cutting wheel to slit the brass sheath on 2 sides then they easily peeled off. I slipped off the rubber hose and out on standard 1/4" fuel hose along with new pinch hose clamps
I also sanded the steel line to bare metal to inspect for pitting and repainted it and the end result looks as if it came this way and it's very easy to service now. Why they used 400 psi rated hose with the crimped on sheathing is a mystery to me. I guess overkill for possible life and death situations is the answer.

Good job !

 

[Daybreak]

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
CROSS-SECTIONAL SHAPE STYLE	ROUND
INSIDE DIAMETER	3.5 MILLIMETERS NOMINAL
LAYER COMPOSITION AND LOCATION	OUTER LAYER BRAIDED COTTON CORD
INSIDE SURFACE CONDITION	SMOOTH
SPECIAL FEATURES	COMES IN A 20 METER ROLL (66 FT.)
MATERIAL	RUBBER BUTADIENE-ACRYLONITRILE CLASS NBR TUBE
MEDIA FOR WHICH DESIGNED	FUEL/OIL, HYDROCARBON SINGLE RESPONSE AND WATER SINGLE RESPONSE AND AIR SINGLE RESPONSE

The fuel return line is 3.5mm ID. As you can see by the above posting the details of this line. Some have used other sizes and hose clamps. But purchasing the correct 3.5mm ID fuel hose makes it stay tight on all the hose barbs without issue.

I found the proper product at autoplicity. It is a 3.5mm ID fuel hose made by CRP CONTITECH. This is a roll which is 5 meters long which will give you enough to replace all your lines and have some in reserve. You can search for below

CRP N203535-5 CONTITECH Diesel Hose

 

[Daybreak]

Howdy,
It seems to be one of the reasons to see fuel on and around the engine compartment. The fuel return line is simple to change out.

 

[sandmanxx]

Howdy,
It seems to be one of the reasons to see fuel on and around the engine compartment. The fuel return line is simple to change out.

I love your way of restating a point.

On a side note I remember when I was missing with my 2004.5 / 5.9 Dodge HPCR diesel fuel lines. I put in a FASS electric inline pump. Bottom line
just get the fuel to the injection pump clean, good flow rate, keep it simple, easy to service, with your favorite flavor of hose / fittings that work for you~

But having said that. See next post.

 

[sandmanxx]

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
CROSS-SECTIONAL SHAPE STYLE	ROUND
INSIDE DIAMETER	3.5 MILLIMETERS NOMINAL
LAYER COMPOSITION AND LOCATION	OUTER LAYER BRAIDED COTTON CORD
INSIDE SURFACE CONDITION	SMOOTH
SPECIAL FEATURES	COMES IN A 20 METER ROLL (66 FT.)
MATERIAL	RUBBER BUTADIENE-ACRYLONITRILE CLASS NBR TUBE
MEDIA FOR WHICH DESIGNED	FUEL/OIL, HYDROCARBON SINGLE RESPONSE AND WATER SINGLE RESPONSE AND AIR SINGLE RESPONSE

The fuel return line is 3.5mm ID. As you can see by the above posting the details of this line. Some have used other sizes and hose clamps. But purchasing the correct 3.5mm ID fuel hose makes it stay tight on all the hose barbs without issue.

I found the proper product at autoplicity. It is a 3.5mm ID fuel hose made by CRP CONTITECH. This is a roll which is 5 meters long which will give you enough to replace all your lines and have some in reserve. You can search for below

CRP N203535-5 CONTITECH Diesel Hose

A word form above

 

[sandmanxx]

Question.. Anyone know the inside diameter of the pump to injector "pipe" / line / metal.....

Also the hard/metal line from tank area to spin filter ??

Thanks

 

[Daybreak]

Howdy,
MEP-8xx generators have fuel return lines. When you see the hoses weeping, you will want to replace the lines. This is the proper 3.5mm ID which pushes on the hose barbs and does not leak.

I repeat = fuel return line... very low pressure line which goes back to the fuel tank.

 

[THENICK]

Howdy,
MEP-8xx generators have fuel return lines. When you see the hoses weeping, you will want to replace the lines. This is the proper 3.5mm ID which pushes on the hose barbs and does not leak.

I repeat = fuel return line... very low pressure line which goes back to the fuel tank.

So I spent all afternoon, going around town, looking for this 3.50 mm braided fuel line. All the auto parts stores. All the small engine repair shops. I found myself at the foreign motorcycle shop. The BMW store. He was the only place in town that had the braided fuel line made in Germany. He didn't have the 3.5 size in stock. Only the 5.0mm. So he will "call me in a bit". When he called, he told me that he can order it out of California. After picking myself up off the floor, I agreed to pay the 160 dollars. (Because I needed it). I gave him my cc. At the last minute, he mentions WURTH FUEL LINES. I told him to hold off on the order. And that I needed to check on something.
YEP. YOU GUESSED IT. I found it on line for 12 bucks. It's also a VW product.
SMILES ALL AROUND

 

[csheath]

K.I.S.S.

Gates 27000 = 1/8" / 3.2mm ID

Gates 27002 = 1/4" / 6.3mm ID

Multi-purpose hose for use on fuel lines, PCV and EEC systems, and for fuel return hose connections on diesel fuel injection systems. Approved for use with leaded and unleaded gasoline, diesel and gasoline blends of ethanol (E85), methanol and ethers (up to the legal limits allowed by the EPA).

Works fine and available at local O'Reilly parts stores around here.

 

[robson1015]

Csheath - That's what I used after seeing your earlier post on fuel lines-thanx