Hudson 1955 Rambler, Technical & Service Manual

Page: 193 / 292

adjust thelength of the push rod so that the
power unit will be in the completely released
position when the brake pedal rod cushion is up
against the floor pan.
To prevent any contact during operation, a
minimum of 3/4" clearance must be maintained
between the center line of the push rod to bell
crank clevis pin and the outer surface of the
front adjusting link lock nut.
T
esting Power Brake System
Road test the car by applying the brakes at the
speed of approximately 20 M.P.H. If the vehicle
does not stop evenly and quickly and the pedal
has a spongy action, it is an indication that air
is present in the hydraulic system. Bleed the
system in the usual manner.
With the engine stopped and the transmission
in neutral, make several pedal applications to
eliminate all vacuum from the system. Depress
the brake pedal and hold in this position. The
pedal should hold a steady position. If the
pedal gradually falls away under this pressure,
the hydraulic system is not functioning proper-
ly.
Depress the pedal and hold in that position
while the engine is started. If the vacuum
system is operating correctly, the pedal will
tend to fall away under the foot pedal pressure
and at the same time less pressure will be
required to hold the pedal in that position. If
this action is not felt, the vacuum power system
is not operating properly.
POSSIBLE DIFFICULTIES AND CORRECTIONS
CONDITIONS AND PROBABLE CAUSE CORRECTIONS
Hard Pedal (Mechanical Condition)
Glazed Linings
Grease or Brake Fluid on Lining
Bind in Pedal Linkage
Hard Pedal (Vacuum Failure)
Faulty Vacuum Check Valve
Collapsed Vacuum Hose
Plugged Vacuum Fittings
Reserve Tank Leaking
Hard Pedal (Power Unit)
Internal Vacuum Hose
Vacuum Leaks in Power Piston
Restricted Air Cleaner
Atmospheric Poppet Not Sealing
Vacuum Cylinder to Master Cylinder Vacuum Leak
Bind in Push Rod and Plunger Action
Grabbing Action in Brakes
Grease or Brake Fluid on Linings
Rough or Scored Drums
Reactionary Diaphragm Leak
Counter-Reaction Spring Broken
Restricted Diaphragm Passage
Faulty Pivot Arm and Vacuum Poppet Action
Bind in Push Rod and Plunger Action
Pedal Goes to Floor
Brake Adjustment
Air
Brake Fluid Leak
Brake Drum Cracked
Compensating Valve Leak
Master Cylinder Plunger Seal Leak
Clean and Adjust
Correct Leak—Reline Brakes
Free Up and Lubricate
Clean or Replace
Replace
Clean or Replace
Replace
If Loose, Replace—Clean Interior of Power
Cylinder Shell
Recondition Power Piston
Clean or Replace
Replace Poppet Valve
Recondition Power Unit
Check Operation and Lubriplate
Correct Leak—Reline Brakes
Clean and Turn Down
Replace
Replace
By-Pass Hole in Gasket not in Alignment—
Clean Passage
Check Operation—Replace
Check Operation and Lubriplate
Adjust
Bleed Brake Lines
Correct—Bleed
Replace
Replace Valve—Bleed
Recondition —Bleed
BRAKES, AND WHEELS-HUBS AND DRUMS 15