Chevrolet Light Duty Truck 1973 Service Manual page 19

longer than those listed above will seriously reduce
engine life and may affect the m anufacturer's
obligation under the provisions of the New Vehicle
W arranty.
A high quality SE oil was installed in the engine at
the factory. It is not necessary to change this
factory-installed oil prior to the recommended
normal change period. However, check the oil level
more frequently during the break-in period since
higher oil consumption is normal until the piston
rings become seated.
NOTE: Non-detergent and other low quality
oils are specifically not recommended.
Oil Filter Type and Capacity
• Throwaway type, l quart U.S. measure, .75 quart
Imperial measure.
• 250 cu. in., 292 cu. in., AC Type PF-25. 307 cu. in.,
350 cu. in. 454 cu. in., AC Type PF-35.
Crankcase Capacity (Does Not Include Filter)
• 292 L6 Engine; 5 quarts U.S. measure, 4.25 quarts
Imperial measure.
• All other engines; 4 quarts U.S. measure, 3.25 quarts
Imperial measure.
Recommended Viscosity
Select the proper oil viscosity from the following chart:
RECOMMENDED SAE VISCOSITY NUMBER
10W , 5W -3 0 , I0 W -3 0 , 10W -40
r i i
.3 0 - 2 0 0 20
TEMPERATURE RANGE ANTICIPATED BEFORE NEXT OIL CHANGE, °F.
NOTE: SAE 5W-20 oils are not recom­
mended for sustained high-speed driving.
SAE 30 oils may be used at temperatures
above 40°F. SAE 5W-30 oils are recom­
mended for all seasons in vehicles normally
operated in Canada.
The proper oil viscosity helps assure good cold and hot
starting.
Checking Oil Level
The engine oil should be maintained at proper level. The
best time to check it is before operating the engine or as
the last step in a fuel stop. This will allow the oil
accumulation in the engine to drain back in the
crankcase. To check the level, remove the oil gauge rod
(dip stick), wipe it clean and reinsert it firmly for an
accurate reading. The oil gauge rod is marked "FU LL"
and "ADD OIL". If the oil is at or below the "A DD "
i i i— i
4 0 60 8 0 100
GENERAL IN F O R M A T IO N AND LU BRICATION
mark on the dipstick, oil should be added as necessary.
The oil level should be maintained in the safety margin,
neither going above the "FU LL" line nor below "ADD
OIL" line.
NOTE: The oil gauge rod is also marked
"Use SE Engine Oil" as a reminder to use
only SE oils.
Supplemental Engine Oil Additives
The regular use of supplemental additives is specifically
not recommended and will increase operating costs.
However, supplemental additives are available that can
effectively and economically solve certain specific
problems without causing other difficulties. For example,
if higher detergency is required to reduce varnish and
sludge deposits resulting from some unusual operational
difficulty, a thoroughly tested and approved additive -
"Super Engine Oil Supplement"- is available.
Drive Belts
Drive belts should be checked every 6,000 miles or 4
months for proper tension. A loose belt will affect water
pump and generator operation.
POSITIVE CRANKCASE VENTILATION
VALVE
Every 24,000 miles or 24 months the valve should be
replaced. Connecting hoses, fittings and flame arrestor
should be cleaned. At every oil change the system should
be tested for proper function and serviced, if necessary.
AIR INJECTION REACTOR SYSTEM (A.I.R.)
CONTROLLED COMBUSTION SYSTEM
(C.C.S.)
The Air Injection Reactor system should have the drive
belt inspected for wear and tension every 12 months or
12,000 miles, whichever occurs first. In addition,
complete effectiveness of either system, as well as full
power and performance, depends upon idle speed,
ignition timing, and idle fuel mixture being set
according to specification. A quality tune-up which
includes these adjustm ents should be perform ed
periodically to assure normal engine efficiency, operation
and performance.
GM EVAPORATION CONTROL SYSTEM
Every 24 months or 24,000 miles (more often under
dusty conditions) the filter in the base of the canister
must be replaced and the canister inspected.
MANIFOLD HEAT CONTROL VALVE
Every 6,000 miles or 4 months, check valve for freedom
of operation. If valve shaft is sticking, free it up with
GM Manifold Heat Control Solvent or its equivalent.
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LIGHT DUTY TRUCK SERVICE MANUAL