The last time I spoke with Brett at Bonaco, he indicated that they now have black anodized fittings, so I ordered replacement AN822-3D fittings and new hoses from the reservoir to the master cylinder with black fittings on each end.  This looks so much nicer now that everything associated with the brakes and rudder pedals is black anodized aluminum.

I torqued down all of the fittings and decided to fill the brake system tonight.  I’m using Royco 782 fluid.  I was able to find quart sizes of this at SkyGeek.com.

Royco 782 is a MIL-PRF-83282 fluid which is the replacement for MIL-H-5606 and has a much higher flash point.  There have been brake fires with MIL-H-5606, so I didn’t want to use that.

The general consensus seems to be to use a pressure system to fill the brake system from the bottom, but people sometimes still have issues with bubbles in the system.  Getting the bubbles out of the system has nothing to do with the direction you fill the system, it’s all about getting a high flow rate through the system.  If the flow rate is too slow, bubbles will get stuck in high spots in the system since they tend to migrate fairly slowly through the narrow lines.  With a high enough flow rate, the bubbles can’t help but be carried along with the fluid.

Instead, what I did was create a closed system to pump the brake fluid through.  I hooked up a fitting and hose to the brake fluid reservoir and put the other end in the can of brake fluid.  I then hooked up another hose to the fitting on the bottom of the wheel caliper and also put that hose in the can of brake fluid.  Now, as fluid is pumped out of the can and through the system, it’s returned back to the can.  All I had to do after that was operate the brake pedals fully and moderately quickly until nothing but clean fluid was being pumped back into the can.  This only took about 30 seconds on each side.  The brakes are absolutely rock solid and no leaks!

The fuel pump needs to be spaced up off the floor a little bit because of the nutplates and protruding screws on the bottom of the fuel pump mounting plate.  I fabricated four aluminum spacers and countersunk one end of each so that it will fit over the dimples in the floor.  I didn’t get any pictures of it, but I then dimpled the floor and installed the fuel pump with some scrap hardware.  I need to order some AN509-8R12 hardware to mount it for good.

After fiddling around with where to mount the fuel pump, I decided not to mount the fuel pump to cross bars on the center cover.  I did this for a couple of reasons.  First, It means that the fuel pump has to come out if I ever need to remove the cover fiddle with the wiring.  Second, the cross bars reduce the vertical space available for wiring under the cover.  Instead, I’m going to mount the fuel pump mounting plate directly to the floor.  I do need to be able to remove the fuel pump and controller if they ever need to be serviced, and I don’t want to have to remove the mounting plate since that will require two people (one for the screws on the outside and one for the nuts on the inside).  To do that, I decided to replace all of the small metric nuts and screws with standard #6 AN hardware.  I installed nutplates on the bottom of the mounting plate.

I then used some short AN515 #6 screws to screw the pump and controller down to the mounting plate.  You can also see that I removed the terminal block and replaced it with a two connector molex connector.

Here’s where the fuel pump will be mounted.  I’ll fabricate some short spacers and the screw this to the floor.

Moving the pump down made it a lot easier to bend this fuel line between the fuel selector and the fuel filter.  There is tons of room around the fuel line, and plenty of clearance from the spar penetration holes for wiring.  This also brings the pump pretty far back which keeps it completely inside the pump cover.

I fabricated the fuel line that runs between the fuel pump and the firewall.  I had previously fabricated this line, but that was for the old pump position and that line would no longer work.  Despite the pump being farther back, this line is shorter because it takes a more direct route.

The line steps down immediately after leaving the pump to go under the cover and then bends slightly to the right to head directly to the firewall penetration.

I cut away a good chunk of the cover so that it can drop in over the pump.  This is so much better than old way I was installing this.  That would have required removing the pump to access the wiring bundle.  I bent a flange in the forward end of the cutout to stiffen the cover in this spot.

The line just touched the forward end of the cutout, so I used my Dremel and sanded away a relief.  There is about 1/4″ of clearance around the line now and nothing can flex that far.  I might still add some silicone wrap here though.

Here’s what it looks like with all of the covers in place.  With everything in its final position, I drilled the cover to the holes that were already in the floor stiffeners

I pulled everything apart to install nutplates and prep everything for final assembly.  While I had the fuel selector mounting plate off the plane, I countersunk all of the screw holes.  I didn’t realize until after doing this that the three holes near the fuel selector didn’t need to be countersunk since there is a cover plate that mounts over this.  It won’t matter though since these will be hidden under that plate.

I riveted the pump cover to the fuel selector cover.  Some people use screws to attach these, but I can’t see why you’d ever care to remove one without the other and rivets are simpler and lighter.

It’s a little hard to see what this is, but it’s a picture of the inside of the two pieces above.  I cut away most of the front of the fuel selector cover since the extra metal inside here served no purpose.

I also installed nutplates on the forward cover.  These allow the forward cover to be attached to the floor stiffeners as well as allowing the pump cover to be attached to the forward cover.

I cleaned the floor well and attached some adhesive tie-wrap mounts.

This is a closeup of the tie-wrap mounts.

I added loose tie-wraps to all of the mounts and then ran wires for the fuel pump.

The ground wire attaches to the firewall ground block and the power wire connects to the VP-X.  I’m really liking wiring with the VP-X since it allows you to do all of the wiring without having to have the panel design done or in the plane.  Once the panel is cut, I just need to run a sense line from the VP-X up to the switch and then the fuel pump wiring is done.

I edge finished the cap strips and drilled them to the center section.  Afterward, I deburred all of the holes inside and out.  Here’s the left side.

The armrests are pretty flimsy as designed.  I’m using some 0.063″ angle to reinforce them.  I used a router to radius the outside corner so that it can tuck into the angle on the armrest.  I drilled them to the flange and will eventually also drill them to the top surface of the armrests.

I also fabricated four of these little supports that will rivet into the bulkheads at each end of the armrests to transfer the load directly into the bulkheads instead of through the wimpy flanges on the armrests.

Here’s how these will mount.  Any load on the armrests will be transferred into the 0.063″ angle.  The angles will sit directly on top of the supports to transfer the load into the bulkhead.  Without these, that little flange just above the angle would have to carry the load.