Evening star., 1953-02-23
Too Little Attention
Paid 10 Hand Brakes
As Safety Factor
By Frederick c. Russell

HAA dAtOl41ObAAC AoAA od4C W1ICk
1t stands unless its parking BRAKE
Is in good health. And those whC
are fighting the battle of acci.
dent prevention are unanimou,
in urging motorists to give more
attention to the condition Of tht
hand-braking system.
Some go so far as to claim
that there would be fewer acci.
dents if more automobiles went
back to the old custom Of call
ing this brake the emergency
brake.
Some drivers fail to reach fol
the hand brake when the ny.
draulic brakes failed. It isn't
too generally understood that the
hand-braking system, while il
may use the same rear brake
shoes controlled by the hydraulic
system, provides a completely
separate way of actuating these
shoes mechanically.
Where a hand brake is located
on the shaft just behind the
transmission it is completely
divorced from the hydraulic
brakes.
Under present-day operating
conditions hand brakes are OF
course. not equal to the four
wheel hydraulic brakes. But they
may stop the car in an emer-
gency, provided they are in nor
NAL condition.
Inspections show that too often
they are not even adjusted to
hold the car in a parked position!
How They Work.
Where the parking brake oper-
ateS as q separate unit behind
the transmission it is an exposed
drum with a contracting band.
It is similar to the type of ex-
ternal contracting brake used on
cars prior to the present internal
expanding type Of four-wheel
brakes.
This brake is subject to be-
coming water soaked or greasy.
It can also pick up dirt and
sometimes twigs and other stray
objects from the road.
Where the parking brake Sys-
tenn operates by means of the
two rear brakes, there are OBJ
jections in the chance that oil
or grease on the brake shoes will
reduce braking efficiency. There
may also be too much brake-shoe
clearance here from overuse of
the hydraulic brakes.
There may be extreme inequal-
1ty of braking force on the rear
wheels. a condition that could
force the car to skid if the
hydraulic system failed and the
driver were relying on the hand
brake alone.
Whether one system is prefer
able to the other is secondary
to the fact that neither system
is worth its weight in scrap iron
unless 1t works well.
Neglect Hand Brake.
Some owners neglect the hand
brake on the theory that they
can just leave the car in gear
when parking it. However, this
cannot be done with cars
equipped with simple fluid drive
or with fluid drive plus a semi
automatic transmission. And
when there are provisions for
parking cars having automatic
transmissions or torque conver-
ters. many owners do not know
how to set the controls properly
In all cases safety suggests set
ting the hand brake, too.
Many drivers do not realize
that the hand brake can be used
smoothly by preventing the latch
from working when pulling back
on the handle. A little practice
here not only would show how tc
use this brake, if an emergency
demanded it, but would also
demonstrate what q shock it is
not to have all four wheels brak-
ing.
To Keep in Shape.
Where a drive shaft hand
brake Is used, cleanliness Is i'm
portant. Next comes condition
of the lining. Then comes care
full adjustment Of the clearance
between the lining and the drum,
because if the lining contacts at
one point before another there
will be ineffective friction and
poor holding qualities.
While these hand brakes on
the shaft are not designed for
use during car movement (al-
though some of the earlier cars
used these for service brakes,
and with a fair degree Of success
before four wheel braking) their
adjustment should be made with
this possibility in mind.
Clearance is usually around
.020 inch, starting the adjust
ment at the anchor bracket and
then turning the guide bolt ad-
justing until the same clearance
is obtained between the band
and the bottom Of the drum. Ar
adjusting bolt nut Is also pro-
vided for giving the same clear
ance between the upper half o1
the band and the drum.
1t would not be possible in
this space to give the methods
for adjusting the drums on the
Drear brakes Of the various types
now in use, but the general rule
is that if the service brakes have
the right shoe clearance, thu
hand brake then merely need:
adjustments to the levers which
force the brake shoes outward
against their drums and to tht
cable equalizers.
Ratchet Important.
The ratchet of the parking
brake is important because If i
doesn't hold, the hand brakes i'm
mediately release. Since holding
the brake shoes in the "on'