[JerryG150]

I'll be ordering more 3/8'' al fuel line coil on Monday. The first template shows a 90 degree bend very near the edge of tank-fuel pump fuel line at the pump side.

I first cut a pice of line 2 feel long that ended up being 23 1/2'' because of an old dull tube cutter (just bought a new one at Home Depot). Then I cut a 24'' line to discover you don't cut the line till the last step. Oh well.

At first I couldn't bend the piece of al. so it had a short enough length of al before the bend. Then I made a 90 degree bend and then snipped off the beginning of the tube to make it short enough. Now when I slip on the nut 'n stuff there is not enough room to make the flare. I have the line done with no flare on either end. At the tank end I can slip the nut 'n stuff and make a flare but no room at the fuel pump end. What am I doing wrong?

Guess I'll finish Section 29 while waiting for the new al. coil to arrive.

I'm also having a problem getting the ferrel to slide close enough to the nut (over the sleeve) to attach the nut to male counterpart on the 90 and 45 degree elbows on the brake lines. Plastic fuel lines and al brake line are a real problem for me!

 

[JBPILOT]

Jerry

I think you will find the tubing-bender they provided in the tool kit will not make a 90 degree bend that close to the end. You either have to buy a different style, or make the line a little longer.

You are correct, putting the inserts in the end of the plastic tubing is not easy. The hot water does help, but you have to be ready as soon as you pul it out of the hot water. It will cool very quickly.

John Bender
Iowa

 

[meadeduck]

Tube Bending

We (I) messed up on the first time I tried bending that @#$% tube because I couldn't figure where to start the bend...anyway, we are also a member of the Buy-Some-More-Tubing Club.
Meade and George
#16

 

[mburch]

Some tips

Jerry,

I have done the plumbing on two RV's now - which doesn't make me an expert, but here are some tips for people new to the wonderful world of aluminum tubing:

• Always deburr the end of the tube after cutting. I use a normal deburring tool for the ID (not too much pressure!) and a blue roloc wheel for the OD.
• When the flaring tool starts to resist your efforts to turn it, you're done. If you crank the tool down until you can't turn it anymore, you've already smashed the flare. Inspect the flared end carefully for cracks.
• Don't forget to put on the nut and sleeve before flaring the end of the tube! I still make this mistake sometimes. Bad language doesn't fix the problem but it makes me feel better.
• To make a bend close to a flared tube end, put on the nut and sleeve and flare the tube first. Make sure the sleeve is all the way up to the flare, then you can make the bend very close to the end. The nut can go around curves that the sleeve cannot.
• If you have to make a piece of tubing that has a lot of bends in it, use individual pieces of scrap tubing to make separate mockups of each bend. Then use these as templates for the final, continuous piece of tubing. I find this approach lets me end up with a really nice-looking finished piece. Use the scrap template pieces to judge where to line up the zero-degree mark on the bender for each bend.
• If you nick, pinch, crimp, or otherwise damage a piece of tubing, it's scrap. Any scratches other than very light, cosmetic surface marking is a no-go in my shop too. If you find yourself asking "is this piece okay?" then it isn't. Do it right and you'll sleep soundly later.
• Buy a whole coil of tubing. It's cheap (especially with the volume discount) and you will need multiple tries to get a piece of tubing right... even after plenty of experience.

Here are my favorite tubing tools... all links go to Aircraft Spruce, but you can get the same items from any of the other many fine vendors out there like Avery, Cleaveland, etc:

• Tubing cutter (always seems to work better than the hardware store one I've got)
• Tubing benders (I use both sizes but you could get away with just the model 368)
• Bender for special applications (very useful for the fuel pump plumbing on an injected RV... maybe not necessary for the 12)
• Flaring tool (everybody and their dog uses this one)

good luck,
mcb

 

[Bob Brown]

Good tips Matt!

I learned most of these things the hard way too. If it makes you feel better Jerry, it took me 38' of 3/8 tubing to make two 24" fuel lines...I also met one of my neighbors who was also at Van's buying more tubing...

 

[JerryG150]

my solution ...

I ordered a dozen new F63-PT-25 brass inserts as well as 9' of brake line plastic tubes & about 30' of aluminum fuel line. I plan on cutting off all the problem ends of my brake line with the brass inserts installed (about 1/2"). Then reboil the tips of brake lines and install new brass inserts and try to keep the sleeve ferrel or the nut attached ferrel close enough to the ends so my female end will reach the threads of the male elbow and screw in. I'm hoping the length of each brake line being about 1/2" shorter than the length suggested won't make a difference. If it does make a difference, I'll have enought newly ordered brake line to start the whole process again.


As far as the fuel line problem, I plan on not making my fuel line (once the new aluminum fuel line arrives priority mail) as the template indicates it should be made. I'll extend the fuel line before the first 90 degree bend about 3/4" from the fuel pump and then extend another length of fuel line somewhere about 3/4" on the line going in the opposite direction so the end pops up in the same spot as it would have without the 3/4" extention.

To add insult to injury I messed up both the 2 AA6 125X1X1 pieces of angle iron to be fabricated on section 29-04 step 4. Both my K 1000-4 drilled rivet holes were uneven (not straight across the center of the piece of angle iron and one 1/4" screw hole drilled out at 3/8" to be able to allow a screw to make it thru to the nutplate. I measured and punched the spot to drill my #40 rivet hole ... put in a cleco to hold the nutplate in place and drilled the second rivet hole and it still didn't work. Twice! Any suggestions?