Cessna 152 - Page 124

SECTION
7
AIRPLANE
&
SYSTEMS
DESCRIPTIONS
BRAKE
SYSTEM
CESSNA
MODEL
152
The
airplane
has
a
single-disc,
hydraulically-actuated
brake
on
each
main
landing
gear
wheel.
Each
brake
is
connected,
by
a
hydraulic
line,
to
a
master
cylinder
attached
to
each
of
the
pilot's
rudder
pedals.
The
brakes
are
operated
by
applying
pressure
to
the
top
of
either
the
left
(pilot's)
or
right
(copilot's)
set
of
rudder
pedals,
which
are
interconnected.
When
the
airplane
is
parked,
both
main
wheel
brakes
may
be
set
by
utilizing
the
parking
brake
which
is
operated
by
a
knob
on
the
lower
left
side
of
the
instrument
panel.
For
maximum
brake
life,
keep
the
brake
system
properly
maintained,
and
minimize
brake
usage
during
taxi
operations
and
landings.
.
Some
of
the
symptoms
of
impending
brake
failure
are:
gradual
decrease
in
braking
action
after
brake
application,
noisy
or
dragging
brakes,
soft
or
spongy
pedals,
and
excessive
travel
and
weak
braking
action.
If
any
c,f
these
symptoms
appear,
the
brake
system
is
in
need
of
immediate
attention.
If,
during
taxi
or
landing
roll,
braking
action
de-
creases,
let
up
on
the
pedals
and
then
re-apply
the
brakes
with
heavy
pressure.
If
the
brakes
be'come
spongy
or
pedal
travel
increases,
pumping
the
pedals
should
build
braking
pressure.
If
one
brake
becomes
weak
or
fails,
use
the
other
brake
sparingly
while
using
opposite
rudder,
as
required,
to
offset
the
good
brake.
ELECTRICAL
SYSTEM
The
airplane
is
equipped
with
a
28-volt,
direct-current
electrical
system
(see
figure
7-7).
This
system
uses
a
24-volt
battery
mounted
on
the
right
forward
side
of
the
firewall
as
the
source
of
electrical
energy
and
an
engine-driven
60-amp
alternator
to
maintain
the
battery's
state
of
charge.
Power
is
supplied
to
a
bus
bar,
and
a
master
switch
controls
this
power
to
all
circuits,
except
the
engine
ignition
system,
clock,
and
flight
hour
recorder
(if
installed).
The
flight
hour
recorder
receives
power
through
activation
of
an
oil
pressure
switch
whenever
the
engine
is
operating,
and
the
clock
is
supplied
with
current
at
all
times.
All
avionics
equipment
should
be
turned
off
prior
to
starting
the
engine
or
using
an
external
power
source
to
prevent
harmful
transient
voltages
from
damaging
the
transis-
tors
in
this
equipment.
MASTER SWITCH
The
master
switch
is
a
split-rocker
type
switch
labeled
MASTER,
and
is
ON
in
the
up
position
and
OFF
in
the
down
position.
The
right
half
of
the
switch,
labeled
BAT,
controls
all
electrical
power
to
the
airplane.
The
left
half,
labeled
ALT,
controls
the
alternator.
7-22
1
July
1978