Chevrolet 10 Series 1968, Service Manual

Page: 351 / 713

ENGINE 6-4
LATERAL PROPER
MISALIGNMENT LATERAL ALIGNMENT
F ig . 5— Point Alignm ent
Excessive point pressure will cause excessive
wear on the points, cam and rubbing block. Weak
point pressure permits bouncing or chattering,
resulting in arcing and burning of the points and
an ignition miss at high speed.
4. Install rotor and distributor cap. Press all wires
firmly into cap towers.
Service Battery and Battery Cables
1. Measure the specific gravity of the electrolyte in
each cell (fig. 6). If it is below 1.230 (corrected to
80°F.) recharge with a slow rate charger, or if
desired, further check battery.
2. Connect a voltmeter across the battery terminals
and measure the terminal voltage of the battery
during cranking (disconnect the coil primary lead
at the negative terminal during this check to prevent
engine from firing). If the terminal voltage is less
than 9.0 volts at room temperature, approximately
80° ± 20°F., the battery should be further checked.
See Section 6Y for further tests.
3. Inspect for signs of corrosion on battery, cables
and surrounding area, loose or broken carriers,
cracked or bulged cases, dirt and acid, electrolyte
leakage and low electrolyte level.
F ill cells to
proper level with distilled water or water passed
through a “ demineralizer” .
The top of the battery should be clean and the
battery hold-down bolts properly tightened. Par­
ticular care should be taken to see that the top of
the battery is kept clean of acid film and dirt.
When cleaning batteries, wash first with a dilute
ammonia or soda solution to neutralize any acid
present and then flush off with clean water. Keep
vent plugs tight so that the neutralizing solution does
not enter the cell. The hold down bolts should be
kept tight enough to prevent the battery from shaking
around in its holder, but they should not be tightened
to the point where the battery case will be placed
under a severe strain.
To insure good contact, the battery cables should
be tight on the battery posts. Oil battery terminal
felt washer. If the battery posts or cable terminals
are corroded, the cables should be cleaned sepa­
rately with a soda solution and wire brush. After
cleaning and before installing clamps, apply a thin
coating of petrolatum to the posts and cable clamps
to help retard corrosion.
If the battery has remained undercharged, check
for loose or defective fan belt, defective Delcotron,
TAKE READING
AT EYE LEVEL
F ig . 6—Testing S p e cific G ra v ity of Battery
high resistance in the charging circuit, oxidized
regulator contact points, or a low voltage setting.
If the battery has been using too much water, the
voltage output is too high.
Service Delcotron and Regulator
The Delcotron and regulator tests during tune up con­
sist of the above battery tests; the condition of the
battery indicating further tests and adjustments as out­
lined in Section 6Y.
Service Belts (Fig. 7)
Inspect belt condition.
Check and adjust if necessary for correct tension of
belt, as follows:
• Using a strand tension gauge, check the belt tension.
• If belt is below the minimum, adjust until the spec­
ified tension is reached. (See Tune Up Chart.)
Fig. 7—C h eckin g Belt Tension
DO NOT SUCK
IN TOO MUCH
ELECTROLYTE
FLOAT MUST
BE FREE
HOLD
TUBE
VERTICAL
I
CHEVROLET TRUCK SERVICE MANUAL