Tip: Brake Lines

[Av8torTom]

Hello Folks,

I recently completed running the aluminum brake lines on my 9A. I sought a lot of advice from fellow builders here and this is what I came up with. I think it worked pretty well. I wish I had taken photos during the install, but I think you'll be able to follow.

First, measure the length of the run (right and left are different), then cut the tubing to length, plus a couple of inches. leave a shallow bend in the tube; DO NOT flare either end. Feed the tube thru the little bulkhead starting by the fuel valve.



Snake the tubing thru the gear weldment (I also used a rubber grommet like for the fuel line), and towards brake line opening in the floor of the fuselage. At this point slip on a spring tubing bender and make the gentle turn down towards the floor. Remove the spring and slip on the ferrule and nut and push the end of the tubing thru the hole until about 4-6" sticks outside. Flare the end while it's outside the fuselage and carefully pull it back inside. Add your AN fitting and make your connection.



Use the spring the make the remaining bends towards the fire wall and cut the tubing to final length. Slip on the ferrule and nut, flare the end and make your AN connection



Use the same technique for the other side.

Be patient, take your time, you can do it.

[rightrudder]

Nice write-up, Tom. What impresses me most is the fuel line that passes through the gear weldment...you aced it! About that time in my build, after three tries and amassing quite the tubing scrap pile, I was wishing I had built a tail dragger. But only for a second.

In that last pic, it looks like you have some sealant on the fittings. These should go together dry; only the NPT fittings need sealant.

[Av8torTom]

Thanks for the heads up on the sealant. I was wondering about that.

[climberrn]

The last pic looks like it has Teflon tape on it. That is a big no no due to the fact that pieces can come loose and clog a line. Sealant or Teflon tape, either one has no business on a flared end. They seal well by having a clean compression surface.

[Av8torTom]

Yes Joel as Doug pointed out I did put sealant (not tape) on the thread of the AN fitting, not the flare. Nevertheless I'm going to remove and clean it off. Thanks for the advice/warning... I'll plead temporary insanity on that one

[Taildrgr]

Thought I'd post this gotcha that happened to me.



I was in the finishing stages on my 7A and had already bled the brakes prior to mounting the wings.

Everyone knows how hard the lower wing bolts are to get torqued on the A model with the gear weldement in the way.

After I spent several hours getting the lower nuts torqued, I noticed that the wrench had crimped the brake line right at the fitting.

Luckily, I cut the line right above the nut and was able to pull/rebend an extra inch on the line.

However, since I had already bled the lines, I had a mess of brake fluid to clean up.

The point is that I might have either been more careful torqueing the wing nuts, or not bled the brakes until after mounting the wings.

Hope this note saves someone some time.

[bret]

I don't have a pic, but same thing, drilling firewall stuff, drilled through the braded brake line....