Hudson 1955 Rambler, Technical & Service Manual

Page: 268 / 292

18 TECHNICAL SERVICE MANUAL
FIGURE 22—Check Valve, Arrows Show
Direction of Normal Flow
The compressor pulley has a center bearing
held in place by snap rings. The pulley
and center bearing is mounted on the
crankshaft of the compressor. The bearing
inner race is a tight fit to the crank-
shaft. The pulley has a circular electro-
magnet mounted omits forward face. Two
circular brass contact rings are on the
rear face of the pulley. A brush holder
bracket is mounted on the compressor body.
One brush is grounded, the other is con-
nected to the live circuit.
A clutch plate with a splined hub is
mounted on the front end of the splined
crankshaft. The hub is mounted to the
clutch plate by torsional springs. The
asbestos clutch place facing is impregnated
with iron filings.
When the air conditioning switch is turned on,
current is directed to the contact brush, the
electromagnet is energized, and the clutch
plate is held in contact with the compressor
pulley. Thus, the compressor is being driven
by the clutch plate.
The electromagnet is not energized in the
"OFF" position of the air conditioning switch
and the clutch plate does not contact the
pulley. Therefore, the compressor is not being
driven as the pulley is free wheeling.
WIRING CIRCUIT
The system is wired so that as the air
conditioning switch is turned on counterclock-
wise, either to the "Low" or "High" position,
the units in the system are energized.
The temperature control thermostat and sole-
noid bypass valve are energized simultaneous-
ly. The magnetic clutch plate on the compressor
drive pulley is also energized and the clutch
engages the drive pulley and the compressor
starts pumping. Until this was done, the drive
pulley has been free wheeling and the compres-
sor has not been operating. The only time
then that the compressor is operating is when
the air conditioning switch is turned on.
The air conditioning switch also controls the
blowers for heater use. The two clockwise
positions, "Low" and "High" operate the blower
motor and fan.
Refer to the Electrical Section for the
wiring diagrams.
SERVICE INFORMATION
The following will outline various service
operations and procedures in servicing the
system. Upon diagnosis of the system, any unit
or part found faulty in operation will be
replaced as a unit. No attempt to adjust any
of the units is recommended. Units such as the
expansion valve and the temperature control
thermostat have been pre-set to operate
satisfactorily at the factory. Should these
units show malfunction, they should be re-
placed.
Compressor service will be outlined in the
compressor section.
The following operations will be referred to
with each service operation in which units or
parts are to be removed from the system. In
such operations, each will be required to be
performed: testing system with gauge set,
discharging, evacuating, purging, and charging
the system. These will be referred to in each
service procedure only as a part of the
operation. The operations are outlined as a
complete operation in the following sections.