I will cover the aluminum brake line later with firesleeve for safety reasons.
Started February 15, 2007
Like so many other things in the homebuilt aircraft world, the builder has many choices when it comes to the brake system. There is single puck, or double puck wheel brakes. There is pilot's side only brake pedals, or you can opt for dual brake pedals (pilot and passenger side). You can mount the reservoir on the engine side of the firewall, on the cabin side of the firewall, or on top of the master cylinders.
Here is my system:
First, I opted to mount my reservoir on the engine side of the firewall.
I figure its easier to check and to add brake fluid there. As I get
older and less limber, I really didn't want to be crawling around under
the instrument panel trying to check or fill my brake fluid. I
also mounted it high enough to be the highest point in the brake system.
It feeds via a tube to a steel "L" fitting with pipe threads.
I will cover the aluminum brake line later with firesleeve for safety
reasons.
Here is the inside view. The 90 degree steel fitting on the engine
side screws into a steel union and through a hole in the firewall (all with
1/8" pipe threads). Washers are placed between the firewall and this
steel "T" enough to get a nice tight fit:
The brass fittings that are screwed into the the "T" are designed for Nylaflow
plastic tubes which will eventually attach to the top of the pilot's side
master cylinders to feed brake fluid to the system.
Since everything attaches to the parking brake valve we will do that next.
I assembled a mounting bracket and cable retainer for the parking brake valve.
The parking brake is a simple on/off valve that has a 45 degree throw.
To set the brake, you step on the brake pedals and pull the cable.
This puts pressure on the wheel brakes, closes the valve and doesn't
allow brake fluid to flow, thereby holding pressure on the wheel brakes.
Here is the mounting bracket and cable retainer made from 3/16" thick aluminum
angle and bar:
The cable retainer is a Mickey Whittenburg design and was made by simply
bolting two strips of 3/16" thick 2" long X 3/4" wide aluminum together,
then drilling a hole straight through the middle, between the two bars.
The hole was one size smaller than the cable casing diameter. When
the cable casing is captured in between the two halves and they are bolted
together as shown above, it locks in place and can't move.
The parking brake valve assembly was mounted to the tubes of the firewall
using adel clamps as shown below:
Then, 1/4" aluminum brake lines were run from the outlets of the parking
brake, down the firewall, around the hole for the heater vent and then along
the bottom tube of the firewall. Then they bend back and run to the
area just in front of the landing gear leg:
As you can see, I have used adel clamps to support it but I will still
make another support somewhere near the middle.
My friend and tech counselor Mickey Whittenburg, showed me a neat trick that
I will show you here. You will need a short length of rubber fuel line
hose and a tie wrap:
Drill a hole where you want the stand-off support to be. I drilled
a hole in the rudder pedal attach bracket. Loop one end of the the
tie wrap through the hose, then through the hole and then back through the
hose again as shown here:
Now put the tube in place on the end of the hose and pull the tie wrap tight
as shown here:
Cut off the tie wrap tail and viola` - you have a very secure stand-off clamp
holding the tube in place.
Oops - I just saw something in the picture above. Looks like I need a shorter
bolt or another washer under that nut that's holding the rudder pedals in
place. There are too many threads showing. I'll make a note of
it and change it out when I return to work on the airplane again.