lostpilot28

lostpilot28

Well Known Member
Does anyone have any tips or tricks to help getting the ends of a stainless steel braided hose in the end of the nut for an AN fitting? I just got some hose in the mail yesterday and have already cut it shorter twice (good thing I bought a little extra length!) and poked my fingers umpteen times. :eek:

I've tried wrapping the ends VERY tight before cutting them but I just can't squeeze them into the fittings. My fingers would appreciate any help.
 
I assume you mean wrapping the hose with tape, because you need to or you have a real mess. Use as little tape as possible and leave it on, if it will fit into the barrel. Otherwise carefully remove it without disturbing the SS braid. It has to be cut with a very fine blade or hose cutting saw or you will splay all the strands. I used a band saw with fine metal cutting blade. Roll the hose to cut the braid circumferentially before completing the hose cut. It is not easy. Mark the hose so you know you got it in the barrel all the way. Once you get it started, screw the barrel on to your mark. You may need to hold the hose in a vice using pipe clamps and something the protect the hose from being chaffed. I used cloth. Then the fitting goes into the barrel and the inside of the hose to form the seal.

I feel your pain,

Roberta
 
tape it, hold it in a vise.... then use a cut off wheel.
P.S. You can only cut it too short once. You can cut too long many times :rolleyes:
 
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The only thing I would add

is to NOT use insulating tape. Istead there is a lcear packing tape 0.5" wide that has srands of fiber in it...It is incredibly strong and you can wrap the hose really tight...which crushes it just a little.

Then cut very gently with the Vans (canopy) cut off wheel.

No prolems if you do it this way.

Frank 7a
 
Does anyone have any tips or tricks to help getting the ends of a stainless steel braided hose in the end of the nut for an AN fitting?
Click to expand...

After you have a clean cut as described by previous posters (do not leave the tape on the braid as you assemble the fitting, the inside of the nut needs to clamp the braid), stick the end of the hose into a bottle of STP Oil Treatment. That is the slimiest stuff known to man and is the secret to getting the hose to easily slip into the AN fitting. Put the AN fitting in a vice with the open end facing you and twist the slimed hose as you push it into the fitting. After the hose bottoms into the fitting, use a Sharpie to make a mark on the braid so you can make sure the hose doesn't back out of the fitting as you insert and tighten the mandrel.

I keep a bottle of STP in the shop for those times when you need an oil-compatible lubricant.
 
lostpilot28 said:
Does anyone have any tips or tricks to help getting the ends of a stainless steel braided hose in the end of the nut for an AN fitting? I just got some hose in the mail yesterday and have already cut it shorter twice (good thing I bought a little extra length!) and poked my fingers umpteen times. :eek:

I've tried wrapping the ends VERY tight before cutting them but I just can't squeeze them into the fittings. My fingers would appreciate any help.
Click to expand...


You need the Koul Tool. I have one..highly recommended..it's a must-have for making your own SS braided hoses. Vans sells them. See
http://www.vansaircraft.com/cgi-bin/catalog.cgi?&browse=tools&product=Tool-Hose-Assy
 
I make up hundreds of braided hoses at work every year, the secret for me is: A clean cut, two TIGHT wraps of masking tape works fine. Then cut it with an abrasive chop saw. Cut slow, it should take 10 or so seconds to cut a hose. A straight die grinder mounted abrasive cut off wheel will work but will never be as clean. Assembly wise, you need to use a vice with proper aluminum hose assembly jaws. I believe Aeroquipt makes them, but I be you can find them in any race care supply catalog (Jegs, Summit Racing, PAW, etc.) Clamp the bell in the jaws sideways and push and turn the hose untill its flush with the bottom side of the threads. Remove it and reclamp it in the jaws verticaly, with the top of the bell just BARELY below the top of the jaws. This keeps your wrench from gouging it up. Then lube it up, you cant use too much oil so pour it on, you got to clean the hose assemblys afterwards anyways. Make sure the inside of the hose and both of the threads are totaly wet with oil. 40 or 50 weight motor oil works fine. Start the fitting in by hand and finish up with a 12 or 15 inch cressent wrench.
 
You did not say if you were doing fuel or brake lines. The -6 is no problem using the solutions listed here; however, on the -4 brake lines,I tried and tried...wrecked lots of hose...said several bad words, and then ordered the hose from A.E.R.O. (advertizes at left). The hose arrived in 2 days, already installed, looks great, and no more bad words...atleast on this topic.
 
OR....

Go down to your local hydraulics shoppe....Great hoses at about 1/3rd the cost...all crimped up beautiful like, as long as you don't mind steel fittings.

Frank
 
Sonny,

I don't particularly like being a nay-sayer, but I do believe that builder-fabbed hoses are questionable in time, money, and integrity. Unless you have lots of practice and the right tools and plenty of blood, it's a learning curve you'll use nowhere else on the aircraft.

Have Precision Hose Technology bid on some Strato-flex hoses made to your spec. You'll get pressure tested teflon with your choice of firesleeve (or not) for not much more than you'll pay buying the components and tools yourself.

John Siebold
Been there, bleed that.
 
RV7ator said:
Sonny,

I don't particularly like being a nay-sayer, but I do believe that builder-fabbed hoses are questionable in time, money, and integrity. Unless you have lots of practice and the right tools and plenty of blood, it's a learning curve you'll use nowhere else on the aircraft.

Have Precision Hose Technology bid on some Strato-flex hoses made to your spec. You'll get pressure tested teflon with your choice of firesleeve (or not) for not much more than you'll pay buying the components and tools yourself.

John Siebold
Been there, bleed that.
Click to expand...


Making hoses is not for those without good attitudes to quality control, that's for sure. Having said that it is enormously convenient. I can make one end fitting and then run the hose and cut it to exactly the precision length for the second fitting. I agree there's not much money to be saved, if any .....but it sure provides accurate hose lengths. And I always use aviation grade fittings and hose.

But you need access to an hydraulic pressure tester.
 
Follow up...

Well, you guys weren't lying when you said it'll make you bleed. Each hand must've been poked a dozen times. As a matter of fact I gave up on trying to get the SS braided part inside the nut. Don't think I'm a wussy, but I really cranked on that hose trying to get it to fit. I checked several websites for suggestions and I tried them all. Literally!

I'm all for quality, but I have to wonder about the purpose of SS braided hose. I'm not going with Fuel Injection, so I'm guessing my fuel pressure will be under 5 psi. I know I'll get a few raised-eyebrows for this, but I'm open to suggestions - I ended up carefully cutting back the SS braiding until the rubber hose (which had SS embedded in the hose) fit inside the nut. I then assembled the fittings - I must say, there wasn't much room and I don't know how SS braiding could've fit in the nut. So I cheated.

Anyone care to chime in and tell me how bad of an idea it was for me to trim back the SS braiding? I kind of thought that it was just for looks.

If it's that big of a deal, I'll probably replace the hose with some type of crush/crimp resistant fuel hose. Like I said, I'm open to suggestions...
 
please, please, PLEASE! replace those hoses. I don't want to get preachy but hundreds of thousands, if not millions of those hose ends have been assembled correctaly. If you cant do that, the solution is not a shortcut, but either change systems or learn to do that on correctaly. Yes, it may work, but how much you have degraded the joint cannot be determined, and something as important as the fuel system, I dont feel there is ANY room for sub-standard assemblies. Are you willing to risk an inflight fire? Possabley hurt or kill yourself, passenger, people on the ground? Have your insurance not pay out a dime when the NTSB determines your plane fellout of the sky due to fuel assemblies you knew were not assembled to specification? Do you feel a DAR will sign off on those hoses when he sees them (god I hope not)?
 
lostpilot28 said:
Anyone care to chime in and tell me how bad of an idea it was for me to trim back the SS braiding?
Click to expand...

OK Sonny, step back and look at the big picture. Compare the cost of a couple hoses to the overall cost of your airplane, and the value of your life.

Personally, I'd rather lose a wing during flight testing than have a fire. You will never be comfortable with what's going on forward of your firewall, and someday, the vibration might just spray fuel in there. I'm sorry if this sounds harsh, but I never mess with substandard fuel systems.

Paul
 
I'm all for quality, but I have to wonder about the purpose of SS braided hose. I'm not going with Fuel Injection, so I'm guessing my fuel pressure will be under 5 psi. I know I'll get a few raised-eyebrows for this, but I'm open to suggestions - I ended up carefully cutting back the SS braiding until the rubber hose (which had SS embedded in the hose) fit inside the nut. I then assembled the fittings - I must say, there wasn't much room and I don't know how SS braiding could've fit in the nut. So I cheated.
Click to expand...

Not good! The integrity of the fitting depends on the hose being pinched between the nut and mandrel. By removing the braid you increased the clearance of the fittings and no doubt significantly weakened the fitting.

Please do not use your hoses as you described them. As others have stated, either get someone to show you how to assemble the hoses or buy ready-made hoses. I consider the hoses to be some of the most flight-critical components on the plane.
 
That's what I thought...

OK, thanks for the clarification...I didn't think they'd pass inspection and I didn't intend on flying with them - I just wanted to hear it from those who know.

For the record, these are not the hoses forward of the firewall. I decided to put in flexible line from the wing tanks to the fuel selector. I believe the risk of fire is significantly lower in that area, but I'm not willing to accept a small risk, so I'll replace them.

What I was trying to get at, however, was that there is a lot of fuel hose out there without SS braiding. I will switch to non-SS braided hose from the wing tanks to the fuel selector, given all the feedback. I just wanted to know if removing the SS-braiding would compromise the low pressure hose the way I built it.
 
Sonny,

The hose lining I consider critical. Go teflon all the way; it last forever, it's impervious to the various fluids in aircraft, and you'll be hardened against anything else (like ethanol) the geniuses in DC mandate in fuel.

Hose manufacturers beef up their hoses to meet various specs and applications far more strenuous than we encounter in our puddle-jumpers (like he-man pick-up truck ads!). Stainless braid is part of the design. You won't need firesleeve on the tank-valve runs, but hose builders can add extruded or tube firesleeve for FWF. Make sure you don't have too small a bend radius anywhere along the route, and that the crimped on fittings will pass through holes. Remember, the first two inches aren't going to bend at all.

I recommend PHT because they took the time to educate me (well, present the information) for an informed decision; prices are good. Spruce and their ilk don't make hoses, their order takers are clueless re hoses.

John Siebold
Look ma, no blood!
 
Update

OK, I figured it out! Woohoo! I was determined to not let the $60 I spent on 5 feet of SS Braided fuel hose go to waste. I think my problem was that I wasn't doing a combination of every trick-in-the-book.

For those who come after me, this is how I did it. I bought a new blade for my band saw. Couldn't find anything higher than 18 teeth per inch, so it had to do.
After I taped the part of the hose I was going to cut (used the fiber striped packaging tape), I took the freshly cut end to a grinding wheel. Very lightly ground off any barbs or stray wires that were sticking up. Kind of beveled it so it wasn't a sharp edge too. Didn't touch the rubber with the grinder.

Taped it again, but with a 1/32 lip of tape hanging over the edge. I then used my fingers to curve that tape over the edge of the hose as a smoother surface in which to slide into the fitting.

Then I put a tie-wrap on it and tightened it down...this is probably overkill, but I figured it may help prevent the braiding from bulging outward while I was pushing it into the AN fitting.

I oiled the AN fitting and twisted the hose in...when it got to the tie-wrap, I clipped it off and pushed it the rest of the way in.

Even after all this, it was still a bear to push that hose in there. I noticed that the fitting that screwed into the backing nut was much harder to turn after the 1/2-way point.

Thanks for everyone's advice...I'm glad it worked!
 
I bought the Koul Tool after reading this thread and I must say that's the easiest way to go. My first one was perfect and every one afterwards was too. I can do one in 6-7 minutes including cutting the hose. I thought $75 was a lot for that tool but it really does do the job as promised. There's a tutorial on their website which details the process.
 
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