Plastic injector fuel return line specifications?

[Carl_in_NH]

Was running both trucks the other night to keep things charged and flowing freely during the cold, and one truck sprung a leak at a Tee fitting for the injector fuel return line.

Is there anything special about this fuel line in terms of specifications? I suspect it's a simple low pressure oil resistant plastic line, but before replacing it I figured I'd check. Is there a i.d. / o.d. specification for what I need to get? I could remove a piece and take it with me to the store, but it's cold out there.

Doesn't take much of a breach in that return line to make a heck of a mess. On the plus side, nothing on the left side of the motor is going to rust soon.

 

[scooter01922]

I hit the hardware store and got new hose, brass fittings, the ferrules and the metal inserts to be used with compression fittings on plastic lines. I think it was 30 bucks for the works. Now i have new lines and fittings all the way to the IP. FWIW if one went the others may not be far behind.

 

[doghead]

DOT airline works fine.

 

[Blood_of_Tyrants]

I think that it is standard 1/4" polyethylene tubing.

 

[gringeltaube]

1/4" polyamide (= Nylon) tubing

G.

 

[jatonka]

I have a roll of NOS clear plastic return line for the multifuel engine. PM if you need any.

 

[Carl_in_NH]

Thanks, guys - much obliged.

jatonka - PM on the way (besides, I need to order a set of spin-on oil filters & adapters).

 

[anthony3478]

I used DOT airhose from NAPA works fine

 

[doghead]

I think that it is standard 1/4" polyethylene tubing.

Polyethylene tubing will not work for a long term fix(emergency only). It will soften and deform over a short period of time.



Also, as many good topics, this has been discussed well before. DOT air line, Fuel line Nylon tube, all good search terms.

 

[acesneights1]

Mine are all brittle and breaking. The question not answered here is where to get the ferules. I went to a few truck parts places and no one has stepped ferules .

 

[gringeltaube]

.....The question not answered here is where to get the ferules.....

Was that question ever asked before, here...?

I just googled for "1/4" Brass Compression Sleeves Ferrules, For 1/4" O.D. Tube, online" ....

One possible source would be this place... They have the inserts, too.


G.

 

[welldigger]

I just used brass plumbing ferrules from home depot. Worked fine.

 

[acesneights1]

Was that question ever asked before, here...?

I just googled for "1/4" Brass Compression Sleeves Ferrules, For 1/4" O.D. Tube, online" ....

One possible source would be this place... They have the inserts, too.


G.

Those are standard ferules. Our Dueces appear to use a stepped one which I have not been able to find other and one guy said he gruond one side of those flat. Someone must carry the correct one.

 

[acesneights1]

Here is a comparison from an ordinary brass ferrule to the specialized steeped one used for the inj return. The one side fits to the male threaded fitting perfectly.

 

[welldigger]

As long as you can get the nut to start then the standard one will work. That's the only issue some have encountered using standard ferrules.

All of my return lines are redone with standard ferrules. No leaks.

 

[Jeepsinker]

Yeah bud, everyone just uses the normal ferrules, and not a single report of a failure related to them reported to date.

 

[m16ty]

I have took the standard ferrules and ground one end flat on a bench grinder. It does make them fit better doing this but as has been said, the standard ferrule without grinding will work.

Be careful picking up ferrules at a hardware store. The last time I did the return lines on a deuce, NAPA didn't have enough ferrules so I went to Lowes and picked some up. When I went to install the ferrules wouldn't go on the line (too small). Upon further investigation, the cheap line they sell at Lowes is just a fraction smaller than the DOT line and the ferrules wouldn't interchange. Now all tubing is measured from the outside dia. but the Lowes ferrules wouldn't work.

 

[rustystud]

View attachment Scan.pdf This is the correct fitting to use. It is called a Hi-Duty Flareless tube fitting. They are used on all the fuel system hoses at the injector pump. I know other fittings will work, and other ferrules too, but this is the correct one. You install it on the tube and tighten it down until the ferrule end snaps off. You will feel this as a sudden giving when you are applying pressure. Just like the crush-sleeve on a Chevy 12 bolt differential.
For those who like to argue, just look up the NSN number.

 

[acesneights1]

Thanks rusty.
Perhaps the e 81LC on this site is the updated version ??



http://www.hitechcontrols.com/pneumatics/couplings/brass-fittings-valves/selection-compression.html

 

[acesneights1]

http://www.supplyhouse.com/Jones-Stephens-C74-158LF-1-4-Lead-Free-OD-Brass-Pilot-Line-Breakaway-Nut



This actually makes perfect sense. It looks lk, e the original was a breakaway. I'll be the guinea pig.