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Nylaflo has a place in our experimental aircraft if you understand its'
usefulness and limitations within the braking system.
Nylaflo (circa 1989) is used on my Lancair 320 from the pilot side brake
pedals to a Matco parking brake and from there, it is encased in Tygon
tubing all the way to the brake fitting. The Tygon tubing is to protect the
Nylaflo from chaffing, abrasion and kinking. There is a ninety degree bend
from the gear leg towards the back thence into a gentle ninety degree bend
to travel along the rear spar. This routing provides for very little
bending and twisting on the brake line when the gear is raised. There are
no brakes on the copilot rudder pedals because of early problems with the
Matco cylinders locking up if the pilot applies brakes and then the copilot
followed by the pilot releasing pressure and then the copilot. The pilot
master cylinders were replaced with a remote reservoir and Matco cylinders
with a larger piston so that enough pressure could be applied to the brake
pads so the airplane could be held at 2000 RPM. I have had to replace brake
pads every year, representing about 100 operations (takeoffs and landings),
because of uneven wear. Each operation represents about 1 mile of taxiing
with 12 turns at my local airport. My home airport runways are long and
wide.
I don't have any problems with Nylaflo brake lines on my 320 because:
1) The lines were carefully installed with proper torque and a protective
sleeve.
2) Its a 320 -- while the plane has been flown at 1960 pounds, landings have
been under the 1800 pound gross weight (usually about 1600 pounds). That
is, the 320 is a relatively light airplane and does not require frequent
heavy braking.
3) I generally use very long runways, seldom braking at all above 30 kts.
4) My turns seem to be evenly split between right and left.
5) I frequently have to tap the right brake to keep taxiing straight -- I do
not "ride the brake".
My 12 year old Nylaflo lines show no evidence of deterioration as of now.
My real concern is with Matco and their systems. Less than 1/2 of the brake
puck engages the brake pad and this causes uneven pressure to the pad, ergo,
uneven wear. This situation can lead to a cocked-puck locked-brake disaster
(do not try to quickly say the last phrase 10 times). Matco has changed the
thickness of the brake mount (1/4 inch aluminum to 1/8 inch steel) and
machined the matching wheel differently to account for this without changing
part numbers. At one point, Lancair changed the length of the axle. Matco
has also changed the material used in the brake disk (newer ones are
harder). I worry a lot more about the wheels and brakes than about the
Nylaflo.
We have heard reports of Nylaflo problems on Glasairs -- remember that these
are heavier airplanes with larger wheels. Have Lancairs with outback gear
encountered problems with the Nylaflo? Are these Cleveland wheel and brake
combinations?
In any event, the Legacy is a heavier airplane (about 400 pounds) with
Cleveland wheels and brakes, but with the same little bitty brake pad.
These babies are going to heat up. The Cleveland units look substantially
better than the Matcos, especially since the brake pad carrier covers most
of the puck. While I will probably use Nylaflo for most of the brake line
runs, the 12 inches between the line and the brake will not be Nylaflo.
Scott Krueger
N92EX
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LML website: http://www.olsusa.com/Users/Mkaye/maillist.html
LML Builders' Bookstore: http://www.buildersbooks.com/lancair
Please send your photos and drawings to marvkaye@olsusa.com.
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