Brake Lines
April 1987
As mentioned in CP49, page 7, Mike and Sally installed Teflon hose assemblies (Stratoflex part #124001-3CR) in place of the Nylaflow nylon brake lines. These Tefl on hoses are constructed with a seamless, smooth-bore, Teflon inner tube wrapped with a braided stainless steel cover. These hoses come made to length with the ends swaged (not reusable ends) so must be ordered the correct length to suit your particular airplane. They are not cheap but should last the life of the airframe. Mike and Sally ordered theirs from Aircraft Spruce and the cost was approximately $42.00 per 40" length.
These hoses come with a certification tag on them certifying that they are good to 1500psi. Mike installed them from the brake calipers to the master cylingers in one piece, mainly to avoid any more joints than necessary and to help eliminate any place for a leak to develop. The smallest hose available in Stratoflex is a -3, so you will have to use -3 elbows and nipples. For example, at the caliper, Mike used AN822-3D elbows and AN816-3D nipples on the master cylinders. The stainless wrapped Teflon hoses were inserted into a hardware store plastic tube (split the plastic tube lengthwise) then Hot Stuffed to the main gear strut trailing edge. One ply of BID was layed up over the plastic tube to permanently hold the new brake lines in place.
With over 200 hours on their Long-EZ since installing these brake lines, Mike reports that he is one hundred percent satisfied with their performance, and it was well worth the higher cost. While he was at it, he disassembled his master cylinders and installed all new "O" rings, cleaning the parts in de-natured alcohol. The calipers were cleaned up and new "O" rings installed. Dot 5 brake fluid, a 100% silicone brake fluid (a General Electric product purchased at a local hot rod auto parts store), was used and Mike does recommend it since it is completely inert and therefore non-flamable. It does not affect seals, "O " rings, paint, or hoses so there has been zero maintenance on their brake system and we are in the process of installing the same system on Burt's Defiant, N78RA.
Be sure to measure your own airplane to get the Stratoflex the correct length for your aircraft. If you have brake master cylinders up front, as many builders do, you can either run the Stratoflex lines all the way (probably best, but or you can run the Stratoflex up each gear leg and then go with Nylaflow or Nyloseal from there. It will take an AN910-lD coupling (1/8" pipe thread) together with an AN816=3D nipple and a 268P male connector on each side.