1935 Cadillac - GM Heritage Center

49
BRAKES
The force thus developed is applied to the relay
or pedal lever and is added to the force applied by
the driver to the pedal. Although the assister is
connected to the pedal assembly, it does not
interfere with the pedal action, and the foot brakes
can be applied whether the engine is running or
not. Also, the assister does not affect the adjustments
of the brakes or any of the brake connections
up to the pedal.
The control is positive, the valves being regulated
by the movement of the pedal itself. The
assister develops power only while the brake pedal
is moving forward. As soon as the pedal stops,
the assister ceases to build up any force and
merely helps to hold the position which has been
reached.. The assister releases automatically
when the pedal is released.
No attempt should be made to disassemble the
brake assister. In the event that the assister unit
cannot be made to function satisfactorily, it
should be returned to the factory on an exchange
basis.
The service operations and adjustments of'the
brakes are the same on all models except the
Series 10 and 20. The only difference in these
models is that the brake assister is mounted farther
back in the frame X-member than in the longer
wheelbase cars.
L a S A L L E
BRAKES
While the foot brakes on the LaSalle cars are of
the hydraulic type, the hand brakes are mechanically
operated. In this system the brakes are
operated by means of a column of fluid forced
through connecting pipes from a master cylinder
operated by the foot pedal into cylinders attached
to the brake shoes. As this liquid is incompressible,
it transmits the foot pedal pressure to each
wheel brake shoe by means of displacement of
pistons in both the master and wheel cylinders.
Inasmuch as the pressure must be equal in all
parts of the system, no braking action can take
place until all the shoes are in contact with the
drums.
• The brake system consists of a master cylinder
in which the hydraulic pressure is originated;
four wheel cylinders in which the hydraulic pressure
is applied to operate the brake shoes against
the wheel drums; a reservoir or supply tank for
the operating fluid, and the tubing and flexible
hoses connecting the master cylinder to the wheel
cylinders.
The master cylinder is mounted on the frame
at the left side underneath the front floor boards
and is integral with the supply tank in which the
compensating features are incorporated. This
unit performs two functions. Its primary function
is to maintain a constant volume of fluid in
the system at all times, regardless of expansion due
to heat or contraction due to cold. The secondary
function is its action as a pump during the bleeding
operation.
The wheel cylinders are of the floating, singlepiston
type. The cylinder is anchored to one
brake shoe while the piston is connected to the
other shoe by means of a link.
The front wheel cylinders have a larger bore
than the rear cylinder; consequently the front and
rear cylinders are not interchangeable. This
arrangement of the wheel cylinder gives a braking
ratio of 56 per cent on the front and 44 per cent on
the rear.
The pistons in both the master cylinder and the
wheel cylinders are provided with cup packings
which act as seals to prevent the loss of brake
fluid and consequently the braking pressure.
The hand brake lever operates the rear wheel
brakes through a mechanical linkage. The hand
lever is connected by a pull-rod to a cross shaft
mounted on the X-member of the frame. This
cross shaft in turn is connected to each rear brake
with a steel cable. The rear brake shoes are
operated mechanically through a curved lever and
strut rod, within the brake unit to which the
operating cable is connected.
Service Information
1. Brake Assister Service
No attempt should be made to disassemble the
brake assister on Cadillac cars and service it in
the field. In the event that the assister unit
cannot be made to function satisfactorily, it
should be returned to the factory on an exchange
basis.
2. Regrinding Brake Drums
The brake drums supplied by the Parts Division
are finish-machined at the factory before being
shipped. This eliminates the necessity of finishmachining
the drum after installing it on the
wheel. Careful alignment of the drum on the
hub, however, is of particular importance.
There is a limit to the amount of metal that can
safely be removed from a drum when regrinding.
The drums must not be ground out more than .030
inch over the original limit of the inside diameter.
When brake drums are too thin, the excessive heat
that frequently develops will cause them to distort
and warp. Also the enlarged inner diameter of the