Brakes & Fuel Selector

First up tonight was installing the brake fluid reservoir to the firewall.  Because of the variability in firewall forward design, pretty much everything that goes onto the firewall has to be laid out and drilled.  Some pass throughs I will probably wait on until I have the engine to be sure I get them in the right location, like the holes for the throttle cable, mixture, etc.  The brake cylinder doesn't depend on the engine type, so I went ahead and put it where Van's calls out.  It was a little fiddly, since there are two bolt holes to drill, but then a larger 1/2" hole centered below them for the brake line fitting.  After a lot of measuring of the part and double and triple checking, I drilled.  Thankfully the hole ended up where it needed to be.  I still haven't decided if I'll put fiberfrax on the front side of the firewall or not (fiberfrax with stainless foil over it - for greater fire resistance and maybe an extra 60 seconds when I need it most.  There are a lot of arguments about whether or not it really matters.).  If I do, at some point I'll have to pull this cylinder and all other items mounted to the firewall off so I can make a template to cut out mounting slots in the fiberfrax.

I torqued down the bolts, so it's all ready for brake line fitting.

To get started on the fuel system, I took apart the Andair fuel selector valve to change the fittings to the orientation I need.  Based on the directions, I cut a 1 1/8" hole in the aluminum mounting plate that connects it to the wing spar carry through bulkhead.  I shouldn't have trusted the instructions.  Apparently they've changed their design and didn't update the instructions.  The part of the valve that sticks up through the mounting plate is now just 1", not 1 1/8".  It doesn't really matter since mounting screws hold everything on, but with the selector flopping around in the mounting plate, it was really hard to get it lined up for drilling the mounting holes.  3D printing to the rescue!  It took all of 15 minutes to draw and print a collar (the black ring you see around the top of the selector) so that I could more easily center the part in the 1 1/8" hole.  With that done, I drilled the 3 mounting screw holes (not shown in the picture below - the two holes in the plate by the big center hole were pre-drilled by Van's for their own fuel valve.  These holes will get covered up.).

I put nutplates on the valve to make it easier to attach vs using bolts and nuts.

Here it is temporarily installed so I can use it to lay out the fuel lines.  I countersunk the top cover to accept flat head screws vs pan head.  I had to place an order from Aircraft Spruce tonight, so I ordered a few stainless screws.  I think they'll look a lot nicer than the gold cad plated ones.

I started measuring and thinking through how the fuel lines would go.  The fuel line is still soft aluminum 3003, but  it's 3/8" and has a thicker wall thickness than the 1/4" vent tubing.  It's much more difficult to bend by hand.  I practiced a few flares to ensure I knew what changes had to be made for the bigger material (turns out it's the same 4 1/4 turns by the flaring tool as the smaller 1/4" tubing is), then cut a piece to length and made my first bend....and subsequently put a kink in the pipe because I hit it on the edge of the tubing bender.  So scrap that 2' of tubing!  That'll be my practice piece I guess.  Van's gives you juuuust enough tubing to get by with maybe one oops.  I don't like that pressure to potentially put a piece of fuel line in that I'm not 100% happy with, so I decided to order a couple of 12' rolls of extra 3/8 and 1/4 tube.  Of course it's backordered until February like everything these days, but it's super cheap, so worth having on the way so I feel confident in the end result.