Braking in new breaks

On Jun 29, 11:21 pm, "Roger (K8RI)" wrote:
On Thu, 28 Jun 2007 17:13:38 -0700, "karl gruber"

wrote:
I just installed new break pads and am wondering if there is a procedure to
brake them in?

I just put 'em on and use 'em. Never had any problems yet.

They're broke in by the time I get to the end of the taxiway.

Ditto. One side was not as quite effective as the other at first and
the plane had a bit of a tendency to veer to the right with equal
pressure on the pedals, but after a bit more taxiing around and
alternately heating and cooling each side, they evened up nicely. Then
after about 4 or 5 total landings to a full stop, both new brakes
worked perfectly balanced.

On Mon, 2 Jul 2007 08:02:42 -0500, "Jim Burns"
wrote:

The purpose is to wear off any high spots and create a light glaze on the
pads which will remain with normal use. Lack of proper glazing will wear
the pads pre-maturely.

My experience has been it doesn't make any difference. The disks are
high carbon steel and will be covered with rust in only one or two
days. That will take any glaze off the pads the next time they are
used and the whole process begins over again. The High spots will
wear off quickly with normal use.

http://www.parker.com/ag/wbd/cleveland/pdf/Wbtech.PDF has procedures for
both metallic and organic pads. Rapco's procedure is below.

Jim


Rapco, Inc:
Our normal break-in procedure for brake discs using the Rapco, Inc. RA164-
discs, is to get the friction material
hot (Approx. 850 Deg. F.) by performing the following:

a.. Use proper maintenance techniques by insuring that the friction
material is completely clean and dry of all
solvents and hydraulic fluid
b.. Perform a moderate-speed taxi (10-15Kts ground speed), insuring that
you have proper braking
(There will be very little brake action at first).

I've never seen this. Newly applied pads work just as well as they do
after a few weeks. IOW..good. Maybe it's just all that rust in there.

c.. Allow the brake to cool by taxiing across the airport or down field,
without using brakes. If you are not
going to fly the aircraft during the break-in procedure, then allow the
brakes to cool
for 45 min. until the next high-speed taxi stop.
d.. Once you've established positive brake action, you can proceed to a
full-stop landing using significant braking.
(Short field landing procedure). At this time the pilot should notice the
brakes starting to grab more.

OTOH I like short field landings and the majority of the landings in
the Deb would be called short field. OTOH coming in steep doesn't give
much of a roll out either. The Deb and F33 are very good planes for
short field landings.

If this is sufficient braking action, there is no need for another stop
cycle.

So far I've gone through about 5 sets of pads on the Deb. I've never
noticed the brakes to be ineffective with brand new pads, nor have I
noticed any change in their braking action from installation to
several weeks of use. Just a taxi to the end of the runway and go.
OTOH I don't baby them either. For short field I use maximum effort
to land and stop in the shortest space I can manage. In the opposite
extreme I try to land as short as possible with out touching the
brakes.

e.. Perform another short field landing, leaving the landing gear extended
throughout the landing pattern.
This allows the brakes to cool properly before the next heat cycle. After
this landing you should have
significant brake action

I have that to start.

My experience may be different, but I know of no one on the field that
has bothered breaking in the pads or had problems by not going through
a break in procedure. Undoubtedly there are those on the filed who do
go through the procedure, but I don't know who they are. I don't see
anything wrong with going through the procedure you advocate, but I
don't see it as necessary either.

Ditto. One side was not as quite effective as the other at first and
the plane had a bit of a tendency to veer to the right with equal
pressure on the pedals, but after a bit more taxiing around and
alternately heating and cooling each side, they evened up nicely. Then
after about 4 or 5 total landings to a full stop, both new brakes
worked perfectly balanced.

Ya mean lurching from side to side as I taxi is not mormal????

denny