Buick LeSabre 1965 Service Manual page 862

ACCESSORIES
ELECTRO-CRUISE 1 1 - 1 2 9
released to the Neutral or Cruise
position.
4. ENGAGEMENT SWITCH (49000
only) - The engagement switch is
a three-position switch connected
in series with system circuitry.
In the first, or "off" position, the
circuit through the switch is open
and the system is completely dis-
engaged. In the Neutral or Cruise
position, the circuit through the
switch to the relay is closed and,
providing the relay contacts are
in the Down position, the system
is energized. In the third, or
Engage position, the switch to
relay circuit is completed as well
as a by-pass circuit which, when
the relay contact points are in the
Up position, initially energizes the
system.
5. BRAKE RELEASE SWITCH -
The brake release switch is an
electric-pneumatic switch actu-
ated by movement of the brake
pedal arm. Since the switch is
connected electrically in series
with the system supply circuit, it
will fully disengage and "unlock"
the system from cruise operation
when the switch is opened. Open-
ing of the switch requires a mazi-
mum of 1/4" brake pedal travel.
Additional pedal travel will open
a "flap" type valve to vent the
power unit diaphragm chamber to
atmosphere assuring positive re-
lease of the power unit.
1 1 - 2 3 ELECTRO-CRUISE
SERVICE
PROCEDURES
IMPORTANT: Do not lubricate
the power unit bead chain or its
pulley.
The only maintenance required on
the Electro-Cruise is the cleaning
of the power unit air filter. The
recommendations and procedure
for cleaning of the filter are
listed in Group 1.
a. Power Unit Bead Chain
Adjustment
1. Disconnect bead chain adapter
assembly from clevis pin by snap-
ping it free from clevis pin. See
figures 11-177 and 11-178.
2. Adjust engine hot idle speed
to recommended setting, and then
shut off engine.
3. Reattach bead chain to clevis
pin and position carburetor fast
idle cam ot "hot" idle position.
4. Check bead chain to insure
that there is a slight amount of
slack in chain.
NOTE: If chain is too loose or
too tight, loosen jam nut on
threaded stud of throttle lever
adapter assembly, and rotate stud
until chain is just taut. Then back
off threaded stud two full turns.
b. Brake Release Switch
Adjustment
1. Disconnect wiring harness
connector from brake release
switch, and connect an ohm-
meter or test lamp (J-21005)
across switch terminals.
NOTE: If desired, the cruise lamp
of the engagement switch may be
used as a test lamp by unplugging
speed transducer connector at
speedometer, and leaving brake
release switch wiring connector
on switch. Then turn ignition
switch on and press lever of
engagement switch to activate
cruise control lamp. The brake
pedal must be in the released
position (rearward) for the
electro-cruise to operate.
2. Loosen the screw that retains
brake release switch to brake
pedal support bracket. Position
the switch to open the circuit
within 1/4 inch brake pedal travel.
NOTE: An open circuit will be
indicated by an unlit test lamp or
indefinite reading on ohmmeter.
If cruise lamp is used, an open
circuit will be indicated when
light goes out.
3. Tighten adjusting screw and
recheck adjustment of brake
release switch.
c. Disassembly and Assembly
of Power Unit
1. Disconnect the bead adapter
chain attached to the clevis pin
by snapping it free from clevis
pin. See figures 11-177 and 11-
178.
2. Remove the wire harness con-
nector from the power unit coil.
3. Remove engine vacuum and
brake release switch lines from
power unit.
4. Remove screws holding the
power unit assembly to the cowl.
5. Depress the diaphragm return
spring and remove bead chain.
6. Remove the eight 10-32 cap
head screws holding the power
unit to its mounting bracket.
7. Remove the control valve re-
turn spring by depressing with a
knife blade and pushing sideways.
8. Remove control valve.
9. Remove air filter from unit.
10. Wash power unit in a good
detergent.
11. Examine d i a p h r a g m for
cracks and pin holes and replace
if necessary.
12. Check control valve pads and
its sealing surface for dirt, chips
and burrs.
13. Clean or replace air filter as
required.
14. Check for obstructions in air
and vacuum orfices.
15. Reassemble by reversing dis-
assembly prodecure. Care should
be taken when the light cap
screws are placed back on the
mounting bracket to tighten op-
posite sets of screws at a time
and repeat this procedure until
they are all tight.
16. After power unit is rein-
stalled, adjust bead chain (sub-
par, "a") and leak test unit (par.
11-24 subpar. "a").