
ELECTRICAL-BODY AND CHASSIS 12-52
GEAR MECHANISM
NOT IN PARK
RELAY SWITCH ATTACHING SCREW
Fig.
81 -
Drive Gear not
in
Park Position
TERMINAL BOARD
1 2 3
RELAY LEADS (RED)
SOLDER TO NO. 1 TERMINAL
RELAY
COIL-RED
TAN-SOLDER TO
SAME RELAY SWITCH TERMINAL WITH RED COIL LEAD
BLACK WITH PINK STRIPE
ASSEMBLY
1.
If new field and case assembly is being installed,
splice the black and black with pink stripe leads of
the new field with the corresponding leads of the
wiper.
2.
Install the rubber thrust disc, steel thrust disc and
felt lubricating washer in the case assembly bearing
in the order indicated.
3.
Lubricate end of armature shaft that fits in case
bearing. Next, install thrust ball in end of shaft.
4.
Assemble armature in the case and field assembly.
5.
Position the partially assembled brush plate over the
armature shaft far enough to allow re-assembly of
the remaining brush in its brush holder;- then position
the brush plate assembly on the mounting tabs in the
position shown in Figure 78.
NOTE: Circuit breaker ground lead will not
reach circuit breaker terminal if brush plate is
positioned wrong.
6. Center the brush plate mounting holes over the
mounting tabs and bend the tabs toward the brush
holders as required to secure the brush plate in
position.
CAUTION: Be sure tabs are centered in brush
plate mounting holes.
7.
Remove brush retainer clips and resolder circuit
breaker ground lead to circuit breaker. Refer to
Figure
8. If new case and field assembly'is used, scribe a line
on it in the same location as the one scribed on the
old case. This will insure proper alignment of the
new case with the scribed line made on the housing
(Step
1
under Brush Plate Removal).
9. Position armature worm shaft inside the housing and,
using the scribed reference marks, line up as near
Fig.
82 - Relay Assembly Wiring
Fig.
83 -
Terminal Board Resistor
CHEVROLET CHASSIS SERVICE MANUAL

ELECTRICAL-BODY
AND
CHASSIS
12-55
COVER RELAY COIL
ASSEMBLY
PAWL SPRING
a=-
VALVE ASSEMBLY
RATCHET DOG AND _/_ f1
LATCHOUT SPRING ^—-»*
PAWL
RATCHET WHEEL
J
Fig.
SO
-
Exploded View
of
Pump
Relay Switch—Latch and Terminal Board Assembly
1.
Resolder leads
to
wiper terminal board as required
(fig. 82).
2.
Slide terminal board into wiper housing being careful
to position the terminal board resistor lead as shown
in Figure 83.
3.
Resolder leads
to
relay switch assembly
as
required
(fig. 82).
4.
Position relay-switch assembly
in
housing.
CAUTION:
Be
very careful
to
route leads
in
such
a
manner
as to
avoid having them pinched
between relay and wiper housing.
5. Install relay-switch mounting screw.
6. Assemble gear box cover and washer pump assembly
to wiper being careful that the ground strap
is
prop-
erly connected. Refer
to
Figure 75 for assembly
of
washer pump
to
gear housing.
B-Drive Gear Disassembly (Fig.
84)
1.
Remove washer pump assembly.
2.
Remove crank
arm
retaining nut, crank arm, rubber
seal
cap,
retaining ring, shim washers, shield
and
spacer washer in the order indicated.
3.
Slide gear assembly out
of
housing (fig. 85).
4.
Slide drive plate and shaft out
of
gear and remove the
drive pawl, lock pawl
and
coil spring
as
required.
Drive Gear—Assembly
1.
Position drive pawl
on
drive plate
as
shown
in
Fig.
ure 86.
2.
Assemble lock pawl over drive pawl
as
shown
in
Figure
86.
3.
Slide gear
and
tube over
the
drive shaft (fig. 87).
(Move drive and lock pawls
as
required to allow their
respective pins
to fit in the
gear guide channel,
fig.
88).
4.
Holding
the
gear, manually rotate
the
drive plate
until
the
drive
and
lock pawl guide pins snap into
their respective pockets in the gear (fig. 88).
5. Reinstall coil spring between lock
and
drive pawls
(fig. 88).
IMPORTANT: Be very careful
to
maintain lock
and drive pawl guide pins
in
their respective
pockets during Step
6.
6. Assemble inner spacer washer over gear shaft
and
assemble gear mechanism
in
housing
so
that
it is
positioned with respect to the housing in the approxi-
mate location shown
in
Figure 85.
7. Reassemble
the
outer spacer washer, shield, shim
washers
as
required
to
obtain .005"
max.
end play,
snap ring and rubber seal cap in the order indicated.
Refer to Figure 84.
8. Operate wiper
to
"park"
or
"off" position and install
crank arm.
9. Reassemble washer pump
to
wiper (fig. 75).
WASHER PUMP UNIT
The washer pump and/or valve assembly
may be re-
moved from the wiper assembly
as a
unit; therefore,
it is
not necessary
to
remove
the
wiper assembly irom
the
vehicle
if
only
the
washer pump and/or valve assembly
required service.
When
the
pump
is
removed from
the
wiper assembly,
all working parts
are
readily accessible and may easily
be serviced
as
necessary
(fig. 89).
An exploded view
of
the washer pump
is
shown in Figure 90.
Removal and Installation
1.
Raise vehicle hood.
2.
Disconnect washer hoses
and
electrical connections
from assembly.
3.
Remove
3
screws securing washer pump
and
cover
to wiper assembly. Remove pump from wiper gear
box.
4.
Position pump
and
cover assembly
to
the wiper and
install retaining screws.
5. Connect washer hoses
to
valve assembly and wiring
leads
to
pump and wiper terminals.
6. Check operation
of
unit.
CHEVROLET CHASSIS SERVICE MANUAL

ACCESSORIES 15-2
GENERAL DESCRIPTION
The Cruise Master is a speed control system which
employs engine manifold vacuum to power the throttle
Servo unit. The Servo moves the throttle when speed
adjustment is necessary by receiving a varying amount
of bleed air from the Regulator unit. The Regulator
varies the amount of bleed air through a valve system
which is linked to a speedometer-like mechanism. The
speedometer cable from the transmission drives the
Regulator, and a cable from the Regulator drives the
instrument panel speedometer. The. engagement of the
Regulator unit is controlled by an Engagement Switch
located at the end of the turn signal lever. Two brake
release switches are provided: an Electric Switch dis-
engages the Regulator unit and a Vacuum Switch de-
creases the vacuum in the Servo unit to quickly return
the throttle to idle position.
The operation of each unit of the system and the
operation of the entire system under various circum-
stances is described below. Figure 1 shows the location
of the system components within the vehicle-
COMPONENT OPERATION
ENGAGEMENT SWITCH
This switch, located within the turn signal knob, has
three positions. In the fully released position, the switch
passes current through resistance wire to effect a "hold
in" magnetic field in the Regulator solenoid. This cur-
rent is sufficient only to hold the solenoid in place once
it has been actuated by the "pull in" circuit. Depressing
the button partially allows current to flow to the Regu-
lator solenoid at full voltage which causes the solenoid
to pull in. Depressing the button fully opens the circuit
to both the resistance and standard solenoid feed wires
and the solenoid becomes de-activated.
During vehicle operation the three switch positions
have the following functions:
Released
a. System not engaged: No function of the system
will occur although a small current is flowing
through the solenoid via the resistance wire (at
vehicle speeds over 20 mph).
b.
System engaged: The small current flowing
through the resistance wire is holding the solenoid
in the engaged position.
^r-WIRE RELIEF LUG
1 ^-#2-BLUE WIRE
L'3.BLACK WIRE
X /-TURN SIGNAL LEVER
SWITCH—^
^SN
RETAINING RING-^ %^
BUTTON -^
Fig.
2 - Cruise Master Engagement Switch
Partially Depressed
Full voltage is applied to the solenoid (vehicle speed
over 20 mph) which sets the Regulator to maintain the
vehicle speed at the time of Regulator engagement.
Fully Depressed
No electricity flows to the solenoid and the Regulator
is inactive. This position is used by the driver when he
desires to raise or lower his controlled speed. He may
accelerate to his new speed, press the button fully (Regu-
lator releases previously set speed) and release the but-
ton. Upon releasing the button, it passes through the
partially depressed position and the solenoid is "pulled
in", then into released position which provides "hold in"-
current. The driver may also press the button fully with
no pressure on the accelerator pedal. In this case the
regulator releases control of the throttle which returns
to idle and the car slows. When the button is released
the solenoid is pulled in and held in respectively and the
regulator resumes speed control at the speed of the
vehicle during the moment of button release (at vehicle
speeds over 20 mph).
LOCK
NUT
ORIFICE
TUBE
AND
CONNECTOR
ASSEMBLY
AIR FILTER AND
SOLENOID HOUSING COVER
Fig. 3 - Regulator Unit
CHEVROLET CHASSIS SERVICE MANUAL

ACCESSORIES 15-7
6. The car begins to descend a hill--car speed in-
creases slightly and the regulator movements oc-
curing above occur again except in reverse. The
rubber drum is turned further against spring tension
and the air bleed orifices are uncovered more. This
bleeds more air to the Servo reducing the vacuum in
the unit. The diaphragm moves away from the
vacuum port, closes the throttle slightly, and with-
draws the tapered needle from the vacuum orifice.
With the orifice enlarged, the increased vacuum
counteracts the increased air bleed and the dia-
phragm finds a balance again at a reduced throttle
opening.
7.
Driver accelerates by pressing accelerator pedal-
car speed increases and the system responds by
moving the diaphragm to decrease throttle opening.
Since a bead chain is used, the chain merely relaxes
and has no effect on throttle operation. After the
driver releases pressure from the pedal, the throttle
will close until car speed decreases to the pre-set
speed. At that point the Regulator bleeds less air
to the Servo which opens the throttle enough to
maintain the pre-set speed. The system returns to a
stable condition.
8. Driver desires higher controlled speed, presses ac-
celerator until new speed is reached, and depresses
Engagement Switch fully and releases button--speed
sensing assembly tries to turn in a direction that
would decrease the throttle opening until the driver
fully depresses the Engagement Switch. Then the
current is cut off to the solenoid which retracts; the
solenoid nose expands the "U" clip releasing its
grip on the rubber drum. The drum and disk as-
sembly then rotates to a new position because of the
higher car speed. When the solenoid retracts, it also
shuts off vacuum to the Servo and opens the vacuum
port to atmospheric pressure within the Regulator
thereby bleeding down the Servo toward idle throttle
position. As the driver releases the Engagement
Switch, the contacts cause "pull in" and "hold in" of
the solenoid respectively. The system is engaged to
maintain the car speed at the time of Engagement
Switch release.
9. Driver desires lower cruising speed, presses En-
gagement Switch fully, waits until car speed de-
creases to desired speed then releases Switch--when
the Engagement switch is fully depressed the sole-
noid is de-energized causing the vacuum switch to
bleed down the Servo to idle throttle position and the
"U"
clip of the idle bleed valve is released from the
rubber drum. The drum and disk assembly is free
to rotate to a position which corresponds to vehicle
speed as the car slows. When the driver releases
the Engagement Switch, the unit "pulls in" and "holds
in" in the normal manner. The air bleed valve is
clutched to, the rubber drum at the car speed during
switch release. Vacuum is again applied to the
Servo and throttle control is assumed by the Regu-
lator to maintain the car speed at the time of switch
release.
10.
With system in operation, driver applies brakes--
simultaneously the Vacuum Release and Electric
Release Switches operate. The Vacuum Switch
bleeds air into the Servo through the air bleed line
coming from the Regulator. The vacuum is reduced
in the Servo and the throttle returns to idle position.
The Electric Release Switch cuts off power to the
entire system and the solenoid is de-energized. If
the driver removes his foot from the brake pedal the
Electric Switch again feeds voltage to the Engage-
ment Switch and the Vacuum Switch seals the air
bleed line. If the vehicle speed is above 20 mph
when this occurs, reduced voltage will flow to the
solenoid through the 40 ohm wire which will not be
sufficient to "pull in" the unit. If vehicle speed is
below 20 mph no current will flow since the tang
on the rubber drum has opened the low limit switch
points in the Regulator. In either case, after de-
pressing the brake pedal, the system will not con-
trol car speed until the driver operates the engage-
ment switch above 20 mph.
SERVICE OPERATIONS
The components of the Cruise Master system are de-
signed to be replaced should they become inoperative.
The Regulator is calibrated in such a manner during
manufacturing that overhaul operations are impractical.
However, one adjustment may be made to the Regulator to
correct speed drop or increase at the time of
engagement.
BRAKE RELEASE SWITCHES
ELECTRIC
Service — An inoperative switch must be replaced.
Switch replacement is identical to standard brake lamp
switch replacement.
Adjustment- The brake switch plunger must clear the
pedal arm when the arm is moved 1/4 inch measured at
the switch (Figure 7).
VACUUM
Service
—
An inoperative (sticking, plugged, or leaking)
switch must be replaced. Switch replacement is similar
to brake switch replacement. Be certain that the hose to
the switch is connected firmly and is not cracked or
deteriorated.
Adjustment- The brake switch plunger must clear the
pedal arm when the arm is moved 5/16 inch measured at
the switch (Figure 7).
ENGAGEMENT SWITCH
Service
replacement.
The engagement is serviced only by
Removal
1.
Pry the engagement button out of the turn signal knob
with a small thin bladed screwdriver (Figure 2).
2.
With a small hook or long nosed pliers, remove the
switch retaining ring.
3.
.Pull switch outward utilizing the slack in the wiring
harness.
4.
With a small soldering iron, unsolder the wires and
resolder them to the correct terminals of the re-
placement switch.
CHEVROLET CHASSIS SERVICE MANUAL