Project: Cozy4     -     Entry

Oct 19, 2021 16 brake lines Category: C09 Lnd Gear
- I went with PTFE hose with stainless braid, in a single length all the way from the brake caliper to the cylinder. I bought 25' of the hose, and ended up with an extra 2" - I should have ordered 30'. I ran the hose down the center, inside the cabin heat channel. Routing on the sidewall would call for ordering 35'.
- Braided hose has a limited life - I'm accepting that I will replace the brake every 10 years.
- I used AN3 hardware, with 4 straight ends + 4 90 degree fittings. I should have ordered 2 45 degree fittings for use at the calipers - I think that would have been better clocking. Threads of the AN fittings were touched with Gasoila, the thread treatment approved for fuel, oil and solvents.
- I tore out the NylaSeal that had been installed. I have an artifact - the bit of Nylaflow that was embedded in the landing gear.

Almost all of the Matco hardware was kept back by the Craig W., and I had already bought and installed wheels, axles and brakes. On 10/20 I asked Matco to help by selling the fittings connecting reservoirs and cylinders. That plus the (bad idea) wash bottle are the $45 spend of this entry. See picture for the missing bits.

10/31. Brakes are done, with no visible leads. I'll circle back later and check again for air in the lines.
- I again considered changing over to solid -3 tubing with stainless at the ends, but decided against it. The trade off was burst braided tubing vs extra joints. I like the single piece from brake to cylinder, and running the braid in the heater conduit protects the stainless from most all possible accidents. Prior photo shows NylaSeal exiting the cylinder pressure side; new photo shows stainless braided brake line.
- Fitting the reservoir line required a small adjustment to the clocking of the two fittings on the reservoir. The lines from reservoir to cylinder fitting benefit from a dish shaped cut in the nose gear support, already done when I took the project. See the photo - well done, Chad Robinson. If you want to _not_ do this, space the reservoirs more widely.
- The reservoir is a polycarbonate bowl with a, aluminum cap, and there is a small pressure relief / overflow hole in the cap. A mounting bracket holds the resoir on the wall, above the level of the brake. Note that there is a thin washer between the bottom of the bracket and the top of the cap, creating clearance for that pressure relief cap. One of the washers was lost in the project moves, so I replaced the brass one with a steel one.
- I got some bad advice from a Van's forum, where someone recommended a chemistry lab wash bottle as a better way to pump up brake fluid. Don't do it - the brake fluid nipple is pretty darn stiff and hand pressure won't push the fluid past it. A standard oil can has the necessary pressure. It took surprisingly little fluid to fill the brakes, lines, cylinders and reservoirs - I figure 8-10 ounces. I probably spilled another 4 ounces transferring between containers and having hoses pop off.
- Some Maco brake systems recommend a DOT-5 (silicone) fluid. This one uses the traditional 5606, updated to Mil-H-5606.
- The full kit Matco uses a NPT male-female fitting at the bottom of the reservoir, with a slick washer and integral gasket between the fitting and the polycarbonate bowl. Fitting and bending lines was tight, and I'm a big believer in Gasoila for my fuel fittings. That fuel-proof tread sealant is in place of the NPT + gasket. There is very little pressure at the reservoir side, so I'm thinking I keep an eye on it and figure if I need a different solution.
- Hydraulic fluid seeps, creeping along surfaces and contaminating foam. The bottom of this forward area was already sealed with a fuel-proof epoxy; I went back and sealed the holes for ADSB and transponder antennae. The fuel proof epoxy goes all the way back to the instrument panel.


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