Alternate brake line routing for RV-7A/RV-9A

[Pmerems]

Fellow Builders,

I am in the process of running my brake fuel lines in my RV-7A. I have talked with a few RV owners and they mentioned how crowded the center tunnel becomes once you have wires, fuel and brake lines running all together.

After thinking about installing the brake lines per plans (which looks like a pain to snake around), I thought about an easier way. I made a test run and took some photos.


You can see that you don't have to pass the brake lines through any bulkheads. In general the bending is simple and flaring is easy. The majority of the brake lines are tucked under the lower longeron. I have a parking brake but similar routing can be done with the standard firewall mounting bracket.

I don't see any downside to this approach but I would like some feedback from you all.

[Build9A]

The installation looks pretty good to me. You might check to be sure that there is not a vibration and chafing issue between the tubing and the lower longeron. With the distance between clamps, I would think that there might be the possibility for vibration up and down. Over time this might be an issue. With the plans install you brace the lines so that they don't get this up/down movement running along the center section to the firewall. If you keep the brake lines from chafing, it looks like a good alternative.

I actually had more trouble with the fuel lines through the gear weldments. I think I made each side 2 or 3 times.

[craigvince]

Man, I wish I'd thought of that.... It save a lot of space in the center tunnel, too. You might think about encasing the tubing in a sleeve of some sort where it rides along the floor.

[RV7Guy]

Hi Paul,

That is a great idea. My only concern is potential interference with the rudder pedals. The actuation arm for the parking brake sticks out a little. If there is an issue the simple fix would be raising the parking brake above the rudder pedal assembly.

[Pmerems]

Gents,

Thanks for the input. I can sleeve the line with poly tubing but I was also thinking of cutting some foam and encasing the tube and pushing it under the longeron.

As far a the rudder pedal hitting the parking brake this isn't an issue it all clears. The only issue maybe the brake pedal when in full left rudder and applying the brakes. That is why I also posted a question about brake pedal travel. From my test to day there isn't any interference that I am aware of.

[az_gila]

Paul.... this was basically the original routing on the early RV-6A drawings.

The vertical location was not well defined....... and probably was intended to be above the lower longeron angle and through the bottom of the bulkhead.

It also showed a side exit just in front of the wheel, rather than the vertically down exit you have.

Since the overhead pedals were in the early RV-6As, pedal interference should not be a problem. The central cover was only introduced on the -7/9 models... the -6s had a battery immediately behind the firewall... the brake line for the opposite side had to run under, or in front, of the battery...

Perhaps some old -6A web sites might show this early routing...

UPDATE

Found on Gary Zilik's site....



gil A