Chevrolet 1977 light duty truck Service Manual page 22

EXPLANATION OF COMPLETE
1977 VEH ICLE MAINTENANCE SCHEDULE
Presented below is a brief explanation of each of the
services listed in the preceding Complete Vehicle
Maintenance Schedule.
NORMAL VEHICLE USE— The owner's maintenance
instructions contained in this maintenance schedule
are based on the assumption that your vehicle will
be used as designed:
• to carry passengers and cargo within the limita­
tions indicated on the VIN plate,
• on reasonable road surfaces within legal operat­
ing limits, and
• on a daily basis, as a general rule, for at least
several miles.
Unusual operating conditions will require more fre­
quent vehicle maintenance as specified in the re­
spective sections included below.
After each of the following maintenance services
is performed, it is recommended that you insert the
month, day and mileage in the maintenance sched­
ule under the appropriate "Owner Service Log"
column.
LUBE & G ENERAL MAINTENANCE
ITEM
NO . SERVICES
1 CHASSIS — Lubricate all grease fittings in front
suspension, steering linkage, and constant ve­
locity universal joint. Also lubricate transmission
and transfer case shift linkage, hood latch, hood
and doorhinges, parking brake cable guides and
linkage, clutch linkage, propeller shaft slip joint,
universal joints, and brake and clutch pedal
springs. Lubricate suspension and steering link­
age every 2 months or 3,000 miles when oper­
ating under dusty or muddy conditions and in
extensive off-road use. See your Owner's and
Driver's Manual for additional services required
on four wheel drive models. Also see Item 20/
2 FLUID LEVELS—Check level of fluid in brake mas­
ter cylinder*, power steering pump*, battery, en­
gine, axles, transmission, transfer case and
windshield washer*. Check test indicator on bat­
tery (if so equipped). Check coolant for proper
level regularly (daily if necessary, depending on
severity of service), and every 4 months or 6000
miles for freeze protection to at least — 20°F
(— 29°C) or to the lowest temperature expected
during the period of vehicle operation. Proper
' Also a Safety Service
' Also an Emission Control Service
engine coolant also provides corrosion protec­
tion.
Any significant fluid loss in any of these systems
or units could mean that a malfunction is devel­
oping and corrective action should be taken
immediately. On vehicles with disc brakes, a low
fluid level in the brake master cylinder front res­
ervoir could also be an indicator that the disc
brake pads need replacing.
3 ENGINE OIL* — Change each 4 months or 6,000
miles, whichever occurs first, or each 2 months
or 3,000 miles when the vehicle is operated un­
der the following conditions: (a) driving in dusty
conditions, (b) trailer pulling, (c) extensive idling
or (d) short-trip operation at freezing temper­
atures (with engine not thoroughly warmed-up).
See Owner's and Driver's Manual for additional
details.
4 AIR CONDITIONING—Check condition of air condi­
tioning system hoses and refrigerant charge at
sight glass (if so equipped). Replace hoses and/
or refrigerant if need is indicated.
5 TIRES— To equalize wear, rotate tires and adjust
tire pressures as indicated in Owner's and
Driver's Manual.
6 ENGINE OIL FILTER* —Replace at the first oil
change and every other oil change thereafter,
if mileage (6,000 miles) is the determining factor.
If time (4 months) is the determining factor, then
change oil filter with every oil change.
7 REAR AXLE—On 20 and 30 Series trucks, change
lubricant every 24,000 miles. Change lubricant
every 12,000 miles on all type rear axles under
severe operating conditions.
FRONT AXLE AND TRANSFER CASE-Check every
6,000 miles. See Owner's and Driver's Manual
for further information.
8 COOLING SYSTEM - At 12-month or 12,000-mile
intervals, wash radiator cap and filler neck with
clean water, pressure test system and radia­
tor cap for proper pressure holding capacity,
tighten hose clamps and inspect condition of
all cooling and heater hoses. Replace hoses if
checked, swollen or otherwise deteriorated.
Clean exterior of radiator core and air condi­
tioning condenser. Every 24 months or 24,000
miles, drain, flush, and refill the cooling system
with a new coolant solution as described in your
Owner's and Driver's Manual.
9 WHEEL BEARINGS—Clean and repack front wheel
bearings with a lubricant as specified in the
"Recommended Fluids & Lubricants" chart in
this folder.
10 AUTOMATIC TRANSMISSION FLUID-Under normal
driving conditions, change the transmission
fluid and service the sump filter every 24,000
miles. Under unusual conditions such as con­
stant driving in heavy city traffic during hot
weather, trailer pulling, etc., these services
should be performed at 12,000-mile intervals.
See your Owner's and Driver's Manual for fur­
ther details on transmission care.
11 MANUAL STEERING GEAR-Check for seal leakage
around the pitman shaft and housing. If leakage
is evident (solid grease oozing out—not just oily
film), it should be corrected immediately.
SA F E T Y MAINTENANCE
NOTE: Items 12(a) thru (v) can be checked by the
owner or driver while Items 13 thru 22 should
only be checked by a qualified mechanic. It is
particularly important that any safety systems
which may have been adversely affected in an
accident be checked and repaired as necessary
before the vehicle is returned to use.
12 SAFETY CHECKS TO BE PERFORMED BY OW NER OR
DRIVER— The following checks should be made
regularly during operation at no greater interval
than 4 months or 6,000 miles, whichever occurs
first, and more often when the need is indicated.
Any deficiencies should be brought to the atten­
tion of your dealer or another service outlet, as
soon as possible, so the advice of a qualified
mechanic is available regarding the need for
repairs or replacements.
(a) STEERING COLUMN LOCK (IF SO EQUIPPED) -
Check for proper operation by attempting to
turn key to LOCK position in the various
transmission gear ranges when the vehicle
is stationary. Key should turn to LOCK posi­
tion only when transmission control is in
PARK on automatic transmission models or
in reverse on manual transmission models.
Key should be removable only in LOCK posi­
tion.
(b) PARKING BRAKE—Check parking brake hold­
ing ability by parking on a fairly steep hill
and restraining the vehicle with the parking
brake only.
CAUTION: Before making the checks (c) or (d)
below, be sure to have a clear distance ahead
and behind the vehicle, set the parking brake
and firmly apply the foot brake. Do not depress
accelerator pedal. Be prepared to turn off igni­
tion switch immediately if engine should start.