1935 Cadillac - GM Heritage Center

60
BRAKES
LaSalle Brake Diagnosis Chart
Effect
Brake Pedal Goes All
Way Down to Toe
Board
Normal wear on linings.
Leaks in brake system.
Air in brake system.
Remedy
As the brake linings wear it becomes necessary to set the
shoes closer to the brake drums. This condition is indicated
by the necessity for pumping the brake pedal
several times before the brakes become effective. When
adjusting the brakes the drums should be cool and the
shoes should be set as close to the drums as possible without
dragging. The shoe anchor pins should not be disturbed
when making this adjustment to compensate for
lining wear.
A leak in the pipe connections will allow the pedal, under
pressure, to go gradually to the toe board. A cup leak
does not necessarily result in loss of pedal travel, but is
indicated by a loss of fluid in the supply tank. If no leaks
are found either at the wheels or the connections, the
master cylinder should be removed and the bore checked
for scratches and scores.
Air in the brake system will cause a springy, rubbery action
of the brake pedal. If a sufficient quantity of air is present
in the system, the brake pedal will go to the toe board
under normal pressure. All air in the brake system must
be expelled by bleeding as explained in Note 5.
Brakes Drag at All
Wheels
No fluid in supply tank.
Mineral oil in brake system.
The fluid level in the supply tank should be checked. Should
the tank become empty, air will be introduced into the system,
necessitating bleeding as explained in Note 5.
Mineral base oil, such as engine oil and kerosine, when present
in the brake system will cause the cylinder cups to
swell and distort, making it necessary to replace all rubber
parts. To correct this condition, the brake system should
be flushed with alcohol and refilled with standard Lockheed
brake fluid.
Port hole in master cylinder closed.
It is imperative that the port directly ahead of the master
cylinder piston cup be open when the brakes are released.
Should this port be blocked by the piston cup, not returning
it to its proper release position, the pressure in the
system will gradually'build up forcing all brakes to drag.
Loosening one of the bleeder screws at the wheels will
relieve the system of pressure and give temporary relief.
The bleeder screw must be tightened before the car is
driven.
Brake Drags at One
Wheel
Weak or broken brake shoe return spring.
Brake shoes set too close to drum.
Cylinder cups distorted.
Replace spring with a new one.
Readjust shoes to eliminate dragging as outlined in Note 4.
The rubber cylinder cups will swell and become distorted if
kerosine, gasoline or any other similar fluid is used instead
of alcohol to flush the brake system or to clean these parts.
Under this condition the return action of the shoes will be
retarded and the brake drums will heat. The remedy is to
replace the cups with new ones, washing them and flushing
the brake system with alcohol and then to dip the new
parts in brake fluid before reassembling them.
Loose or defective wheel bearings.
Adjust or replace bearings with new ones as necessary.