Chevrolet Low Cab Forward 4500 2019 Series Owner's Manual page 276

Remarks
(1) In case this column is blank,
follow kilometers (miles).
(2) An Emission Control Service.
(3) Initial check at 1 040 km
(650 miles) is required.
(4) See Severe Driving Condition.
(5) A Noise Emission Control
Service.
(6) The California Air Resources
Board has determined that the
failure to perform this maintenance
item will not nullify the emission
warranty or limit recall liability prior
to the completion of vehicle useful
life. GM, however, urges that all
recommended maintenance
services be performed at the
indicated intervals.
Explanation of Complete
Vehicle Maintenance Schedule
The following is a brief explanation
of each of the services listed in the
preceding Complete Vehicle
Maintenance Schedule for gasoline
vehicles.
1. ENGINE OIL : Change at
intervals noted below depending
upon driving conditions.
NORMAL SERVICE - Change
every 12 000 km (7,500 miles) or
12 months whichever occurs first.
SEVERE SERVICE- Change every
4 800 km (3,000 miles) or 3 months
if you often drive under one or more
of these conditions (a) driving in
dusty areas, (b) frequent idling or
idling for long periods, (c) driving
6 km (4 miles) or less in freezing
weather, or other short trips in cold
weather, where the engine does not
thoroughly warm up. Change oil and
filter as soon as you can after
driving in a dust storm.
2. OIL FILTER : Change at intervals
noted below depending upon driving
conditions.
NORMAL SERVICE - Change
every 12 000 km (7,500 miles) or
12 months whichever occurs first.
SEVERE SERVICE- Change every
4 800 km (3,000 miles) or 3 months
whichever occurs first.
Service and Maintenance
3. COOLING SYSTEM SERVICE :
At 24 months or 48 000 km
(30,000 miles) intervals, wash
radiator cap and filler neck with
clean water, pressure test system
and radiator cap for proper pressure
holding capacity, tighten hose
clamps and inspect condition of all
cooling and heater hoses. Replace
hoses if cracked, swollen or
otherwise deteriorated.
Also each 24 months or 48 000 km
(30,000 miles), clean exterior of
radiator core.
4. ENGINE COOLANT : Every
80 000 km (50,000 miles), drain the
engine coolant by opening the drain
plug at the bottom of the radiator
core, flush and refill the engine
cooling system with a new 50/50
engine coolant solution.
5. AIR CLEANER FILTER : Change
every 48 000 km (30,000 miles).
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