Fuel line repair

[RnMAdventures]

We are planning to leave for our trip in less than a week and I noticed a fuel leak from under the engine. After further investigation it is on a fitting on what I think is the return line to the fuel tank. There are two lines running in tandum, one enters the primary fuel filter, the other one is coming from another location (I assume reurin from injectors). The one that is returning from the injectors is the line that is leaking. The location of the leak is between the engine and the bulkhead in that open space.

I assume this line is low pressure if it is the return line. If I can fit up in that space, I plan to try and tighten the tubing (which I doubt will work), or unscrewing the fitting and installing a fitting with a quick connect and patching a rubber hose between the two. The long term solution will be to replace the hose (fuel line rated), but do you think the temp repair will work for our trip? (600 miles).

[thomasinnv]

if you do patch in a piece of hose make sure you use diesel rated fuel hose, not just any old fuel hose.

[Scott & Heather]

Mike,

Nice of you to post a photo. Wish everyone did that. Ditto what thomasinnv said. If using a non-diesel hose, it can literally start to drop pieces of the hose into your fuel system. That being said, some fuel hose is rated for both gas and diesel and biodiesel. Where are you located? Can you get to a Pirtek hose store? They would help you in a heartbeat.

[rv_safetyman]

I have to show my ignorance about a product that I spent 34 years working with at Gates.  In the "old days", diesel was much easier to deal with from a chemical resistance standpoint.  Gasoline had high levels of "aromatic hydrocarbons" and they were rather difficult to develop rubber compounds for (and still be competitive).

Now, everything has changed in terms of the gasoline and diesel chemistry. 

I did some poking around on the Gates website, and the fuel hoses that I saw made no distinction between compatibility with gasoline and diesel.

That said, there must be something in diesel today that is hard to deal with.  I recently bought an electric fuel pump for my '56 Chevy and the parts store had different pumps for diesel and gasoline. 

Any of you chemical folks out there that can help us to understand?

For sure, when you buy fuel hose, work with a reputable supplier and buy a name brand.  There is a lot of really terrible  belts and hose coming to the US from off-shore.  If in doubt, I go to NAPA.

Jim

[bevans6]

You can assemble that kind of hose easily at home, I use a couple of wrenches and a vise, but the vise is optional  The ends just screw together and trap the hose.  I cut the hose either with a bench shear or a hacksaw.  Maybe you can find the supplies and replace the hose properly, fairly easily?  When i was doing my engine install I just bought 15 - 20 feet of hose in various sizes, lots of ends, and just made up new hoses for about everything that looked a little old.  If it is the return line and it's after the restriction fitting, it should be quite low pressure.

if you do try this, a top tip:  The outer ferrule that fits over the OD of the hose has a very coarse reverse thread inside it, and to fit it over the hose you simple screw it on counter-clockwise.  Screw it all the way on, back off a quarter inch, get the insert started barely on it's thread, screw the outer all the way back on, then just thread the insert down into the ferrule and done, perfect every time.  Use WD-40 or soapy water for lube.

Brian

[Scott & Heather]

Jim, I have to say I know very little about the subject, but I do know that some diesel fuel additives can be an issue with some hoses. I tried to search around to find some evidence I could share, but I only came up with this PDF from Gates that clearly indicates "some diesel additives cause deterioration".
http://www.gates.com/common/downloads/files/gates/brochure/techtipsform.pdf

It must be hard for the hose manufacturers to keep up with the constant government mandated fuel chemistry changes...plus all the additives in the market. Yikeso...those hose engineers earn their wage.

[RnMAdventures]

Mike,

Nice of you to post a photo. Wish everyone did that. Ditto what thomasinnv said. If using a non-diesel hose, it can literally start to drop pieces of the hose into your fuel system. That being said, some fuel hose is rated for both gas and diesel and biodiesel. Where are you located? Can you get to a Pirtek hose store? They would help you in a heartbeat.

The closest pirtek is in Dallas. I am about to ramp it and see what I can do. The repair doesn't bother me as much as the cramped space and being able to work.

[RnMAdventures]

  If it is the return line and it's after the restriction fitting, it should be quite low pressure.

Thanks for the tip, one question. Does anyone know where the restriction fitting is on a PD4106. I assume it would be in the rear at the engine, but I am not sure.

[rv_safetyman]

Scott, great find!  That begins to give definition as to why hose choice is pretty critical.  Gates has some additional technical bulletins here:

http://www.gates.com/index.cfm?location_id=3080

The bulletin on 4219D is interesting and has the following statement:

4219D also exceeds the proposed SAE 30R 13 Bio Diesel Standard. Gates
Technical testing states Fuel Line 4219D meets the proposed SAE J30R13
Standard for BioDiesel @ Temperature range -34°C (-29°F) to 135°C
(275°F), with intermittent use up to 150°C (302°F).
 
Gates customers can use 4219G or 4219XL (SAE 30R7) Fuel Lines for Bio
Diesel applications at temperatures up to 65°C (150°F) in addition to its
normal SAE 30R7 fuel applications.

That is about clear as mud to me.  Kind of sounds like standard 30R7 would work for most diesel applications? 

The 4219D document mentions SAE 30R13.   That opens up a whole new can of worms.  Here is Gates take on that:

www.gates.com/oreilly/tech_tips/InstallCorrectFuelLineHose.pdf

Both 30R9 and 30R13 have a Viton inner liner.  Certainly that is the safest way to go.  Would bet that it will cost an arm and leg.

I used Aeroquip AQP hose with the stainless wire reinforcement.  When I was involved, it was always "king of the hill" and we tried to duplicate it without success (too costly).  I looked at the Aeroquip site and it does not describe the tube stock, but I am reasonably certain that it will handle anything we can present to since it is designed for racing fuel.  They have a non-stainless version:

http://www.summitracing.com/search/Brand/Aeroquip/Product-Line/Aeroquip-AQP-Socketless-Hose/?autoview=SKU

Lots of folks use inexpensive DOT air brake tubing.  I think some OEMs use DOT tubing for the non-flexible fuel lines.  I used the DOT tubing from the tank to a location close to the filter and then connected with AQP to the filter and from the remote filter to the pump on the supply line.  Can't recall what I did on the return line.

Fuel hose has certainly got complicated since I retired in '99

Jim

[challenger440]

Once you get the fuel  line off and clean up the fitting, you should be able to see what size it is.  It should be stamped on the fitting.  dash 6 most likely.  Take your fitting to a truck repair shop and they should have the correct hose.  The hose's are sized by dash8, -6, etc.  Screw the ends back on and good to go.   Worked on my MCI anyway.   

As far as if the fuel will eat the new diesel fuel line, I have no idea.  j m

[RnMAdventures]

Well it went from bad to worse pretty quick. While I was putting it up on ramps the tubing blew apart, and made a mess. I got it up on the ramps ok. Well the tubing is copper and I tried to cut it and put another fitting on it, but the tubing is real thin there. I traced it back through the bulk head and found a spot where it looks better. I did some test with it compared to a new piece of tubing and it doesn't have the strength the new tubing has, but it seems acceptable for now. (On a side note one of the copper air lines started hissing at me when was under there... when the fuel line is fixed then its the air line. )

The line it bolts to also formed a leak when I was testing my first attemped repair. Right now the game plan is to overlay about 6-8 inches of high pressure fuel injector hose (rated for diesel) over the good section of tubing and run it back to the engine compartment. I am going to overlay the fuel line with heater hose to protect it from the bulk head.

One of my fears was having fuel line issues. I am glad it happened in my driveway rather than on the road. I am gaining a lot of experience from this. One interesting thing I noticed was the fitting appeard to be brass, but the tubing it copper. I got a copper fitting from home depot and was going to use it until the line it was attached to developed a leak. Right now I see that I am going to have to repair my fuel lines this summer. This particular line appears in worse shape than the rest.

[eagle19952]

I am glad it happened in my driveway rather than on the road. I am gaining a lot of experience from this......

Read what you wrote.
And then FIX it properly.

[RnMAdventures]

I am glad it happened in my driveway rather than on the road. I am gaining a lot of experience from this......

Read what you wrote.
And then FIX it properly.

Just so I save face here.... my intention is NOT to do a halfass repair. There are two sides of this coin. One is having the ability to move it back to storage before the HOA goons come after me with pitch-forks (road fix)... the other is repairing the line properly (replacing the bad line). I started the repair trying to think inside my box... now I am way outside of it. Which is fine... just not comfortable.

When I repair something I tend to try to go back original if possible. Going back to original in this case does not look like an option, so I have to figure out another long term option. I have read on here where one person used air line hose to make a repair. I would have never thought of it, but it worked for their situation. Up until last night I though I was going to have to access the service channel topside. Which would be a MUCH bigger job than taking the few screws off the bottom side. I didnt' know how to access it. You don't know what you don't know.

There is a place up the road that makes custom lines for all applications. I am considering getting them to make up a line long enough to go from the fuel tank connection all the way back to the bulk head connector by the engine. I think I will have to drop out of the service channel before the fuel tank bay and run the line through the wall of the bay. In my opinion, that is the best fix.

For the record, I will fix this properly.

[rv_safetyman]

Mike, when you do the final fuel line repair, consider the DOT tubing for the lines that do not flex.  It is cheap and made for truck and bus applications.

Along the same line, when you replace your air lines, I would use the DOT tubing.  That is the standard today for all commercial vehicles with air brakes.

An excellent source for DOT tubing is:

http://www.mcmaster.com/#d.o.t.-tubing/=gk79wt

After I went to the McMaster page, I looked and the tubing is rated for air only.  I am pretty sure that my Eagle came with DOT tubing for the fuel system (non-flexible part of the system).  I will do some more checking to see if I can find a definitive "approval" for DOT tubing and diesel.

Jim

[bevans6]

First, I have to apologize, I did not notice that the line in question was a hard line so I went on about how to make a soft line...  kind of silly.  My second reason for posting that just to say that the soft line that I have been using is fabric covered, has a mesh steel inner liner and is rated for both air and fuel or even oil applications, universal hose so to speak.  It's probably the most expensive hose option, but since I use it for everything and buy it in bulk it works for me. 

Cheers, Brian OUT!