2003 CHEVROLET SILVERADO Owners Manual

100,000 Miles (166 000 km)
qInspect spark plug wires.An Emission Control
Service.
qReplace spark plugs.An Emission Control Service.
qChange automatic transmission ¯uid and ®lter if
the vehicle's GVWR is over 8600 lbs, if the
vehicle has an Allison transmission or if the vehicle is
mainly driven under one or more of these conditions:
þ In heavy city traffic where the outside
temperature regularly reaches 90ÉF (32ÉC) or
higher.
þ In hilly or mountainous terrain.
þ When doing frequent trailer towing.
þ Uses such as found in taxi, police or delivery
service.
qIf you haven't used your vehicle under severe service
conditions listed previously and, therefore, haven't
changed your automatic transmission ¯uid, change
both the ¯uid and ®lterqAutomatic Transfer Case Only: Change transfer case
¯uid
qExcept 8.1L V8 Engine: Inspect Positive Crankcase
Ventilation (PCV) valve.
An Emission Control
Service.
150,000 Miles (240 000 km)
qDrain, ¯ush and re®ll cooling system (or every
60 months since last service, whichever occurs ®rst).
See
Engine Coolant on page 5-30for what to use.
Inspect hoses. Clean radiator, condenser, pressure
cap and neck. Pressure test the cooling system
and pressure cap.
An Emission Control Service.
qChange ®ve-speed manual transmission ¯uid (with
4300 V6 or 4800 V8 engines only).
qInspect engine accessory drive belt.
An Emission
Control Service.
200,000 Miles (332 000 km)
q6000 V8 Engine Only: Change ®ve-speed manual
transmission ¯uid.
6-11

Part B: Owner Checks and Services
Listed in this part are owner checks and services
which should be performed at the intervals speci®ed to
help ensure the safety, dependability and emission
control performance of your vehicle.
Be sure any necessary repairs are completed at once.
Whenever any ¯uids or lubricants are added to your
vehicle, make sure they are the proper ones, as shown
in Part D.
At the First 100, 1,000 and 6,000
Miles (160, 1 600 and 10 000km)
Check dual wheel nut torque. For proper torque, seeCapacities and Speci®cations on page 5-118.
At Each Fuel Fill
It is important for you or a service station attendant to
perform these underhood checks at each fuel ®ll.
Engine Oil Level Check
Check the engine oil level and add the proper oil if
necessary. SeeEngine Oil on page 5-16for further
details.
Engine Coolant Level Check
Check the engine coolant level and add DEX-COOLž
coolant mixture if necessary. SeeEngine Coolant
on page 5-30for further details.
Windshield Washer Fluid Level Check
Check the windshield washer ¯uid level in the windshield
washer tank and add the proper ¯uid if necessary.
See
Windshield Washer Fluid on page 5-43for further
details.
At Least Once a Month
Tire In¯ation Check
Visually inspect your tires and make sure tires are
in¯ated to the correct pressures. Don't forget to check
your spare tire. See
Tires on page 5-69for further
details.
Cassette Tape Player Service
Clean cassette tape player. Cleaning should be done
every 50 hours of tape play. SeeAudio System(s)
on page 3-71for further details.
6-12

At Least Twice a Year
Restraint System Check
Make sure the safety belt reminder light and all your
belts, buckles, latch plates, retractors and anchorages
are working properly. Look for any other loose or
damaged safety belt system parts. If you see anything
that might keep a safety belt system from doing its
job, have it repaired. Have any torn or frayed safety belts
replaced.
Also look for any opened or broken air bag coverings,
and have them repaired or replaced. (The air bag
system does not need regular maintenance.)
Wiper Blade Check
Inspect wiper blades for wear or cracking. Replace
blade inserts that appear worn or damaged or that
streak or miss areas of the windshield. Also see
Cleaning the Outside of Your Vehicle on page 5-103.
Spare Tire Check
At least twice a year, after the monthly in¯ation check of
the spare tire determines that the spare is in¯ated to
the correct tire in¯ation pressure, make sure that
the spare tire is stored securely. Push, pull, and then try
to rotate or turn the tire. If it moves, use the wheel
wrench/ratchet to tighten the cable. See
Changing a Flat
Tire on page 5-80.
Weatherstrip Lubrication
Silicone grease on weatherstrips will make them last
longer, seal better, and not stick or squeak. Apply
silicone grease with a clean cloth. During very cold,
damp weather more frequent application may be
required. See
Part D: Recommended Fluids and
Lubricants on page 6-19.
Manual Transmission Check
Check the transmission ¯uid level; add if needed. SeeManual Transmission Fluid on page 5-28. Check
for leaks. A ¯uid leak is the only reason for ¯uid loss.
Have the system inspected and repaired if needed.
Automatic Transmission Check
Check the transmission ¯uid level; add if needed. SeeAutomatic Transmission Fluid (Except Allison
Transmissionž) on page 5-23orAutomatic Transmission
Fluid (Allison Transmissionž) on page 5-26. A ¯uid
loss may indicate a problem. Check the system
and repair if needed.
6-13

Hydraulic Clutch System Check
Check the ¯uid level in the clutch reservoir. SeeHydraulic Clutch on page 5-29. A ¯uid loss in this
system could indicate a problem. Have the system
inspected and repaired at once.
At Least Once a Year
Key Lock Cylinders Service
Lubricate the key lock cylinders with the lubricant
speci®ed in Part D.
Body Lubrication Service
Lubricate all body door hinges, hood latch assembly,
secondary latch, pivots, spring anchor, release
pawl, tailgate hinge, tailgate linkage, tailgate handle
pivot points, latch bolt, fuel door hinge, locks and folding
seat hardware. Part D tells you what to use. More
frequent lubrication may be required when exposed to a
corrosive environment.
Starter Switch Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular
brake. See
Parking Brake on page 2-44if
necessary.
Do not use the accelerator pedal, and be ready to
turn off the engine immediately if it starts.
3. On automatic transmission vehicles, try to start the
engine in each gear. The starter should work only
in PARK (P) or NEUTRAL (N). If the starter works in
any other position, your vehicle needs service.
On manual transmission vehicles, put the shift lever
in NEUTRAL (N), push the clutch down halfway
and try to start the engine. The starter should work
only when the clutch is pushed down all the way
to the ¯oor. If the starter works when the clutch isn't
pushed all the way down, your vehicle needs
service.
6-14

Automatic Transmission Shift Lock
Control System Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough room
around the vehicle. It should be parked on a level
surface.
2. Firmly apply the parking brake. See
Parking Brake
on page 2-44if necessary.
Be ready to apply the regular brake immediately if
the vehicle begins to move.3. With the engine off, turn the key to the RUN
position, but don't start the engine. Without applying
the regular brake, try to move the shift lever out
of PARK (P) with normal effort. If the shift lever
moves out of PARK (P), your vehicle needs service.
Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition key to LOCK in each shift lever position.
·With an automatic transmission, the key should turn
to LOCK only when the shift lever is in PARK (P).
·With a manual transmission, the key should turn to
LOCK only when you press the key release button.
On all vehicles, the key should come out only in LOCK.
6-15

Parking Brake and Automatic
Transmission Park (P) Mechanism
Check
{CAUTION:
When you are doing this check, your vehicle
could begin to move. You or others could be
injured and property could be damaged. Make
sure there is room in front of your vehicle in
case it begins to roll. Be ready to apply the
regular brake at once should the vehicle begin
to move.Park on a fairly steep hill, with the vehicle facing
downhill. Keeping your foot on the regular brake, set the
parking brake.
·To check the parking brake's holding ability: With
the engine running and transmission in
NEUTRAL (N), slowly remove foot pressure from
the regular brake pedal. Do this until the vehicle is
held by the parking brake only.
·To check the PARK (P) mechanism's holding ability:
With the engine running, shift to PARK (P). Then
release the parking brake followed by the regular
brake.
Underbody Flushing Service
At least every spring, use plain water to ¯ush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.
6-16

Part C: Periodic
MaintenanceInspections
Listed in this part are inspections and services which
should be performed at least twice a year (for instance,
each spring and fall).
You should let your dealer's
service department do these jobs. Make sure any
necessary repairs are completed at once.
Proper procedures to perform these services may be
found in a service manual. SeeService Publications
Ordering Information on page 7-9.
Steering and Suspension Inspection
Inspect the front and rear suspension and steering
system for damaged, loose or missing parts, signs of
wear or lack of lubrication. Inspect the power steering
lines and hoses for proper hook-up, binding, leaks,
cracks, cha®ng, etc.
Exhaust System Inspection
Inspect the complete exhaust system. Inspect the body
near the exhaust system. Look for broken, damaged,
missing or out-of-position parts as well as open seams,
holes, loose connections or other conditions which
could cause a heat build-up in the ¯oor pan or could let
exhaust fumes into the vehicle. See
Engine Exhaust
on page 2-51.
Fuel System Inspection
Inspect the complete fuel system for damage or leaks.
Engine Cooling System Inspection
Inspect the hoses and have them replaced if they
are cracked, swollen or deteriorated. Inspect all pipes,
®ttings and clamps; replace as needed. Clean the
outside of the radiator and air conditioning condenser.
To help ensure proper operation, a pressure test of
the cooling system and pressure cap is recommended
at least once a year.
6-17

Throttle System Inspection
(V6 Only)
Inspect the throttle system for interference or binding,
and for damaged or missing parts. Replace parts
as needed. Replace any components that have high
effort or excessive wear. Do not lubricate accelerator
and cruise control cables.
Transfer Case and Front Axle
(All-Wheel Drive) Inspection
Every 12 months, or at engine oil change intervals,
check front axle and transfer case and add lubricant
when necessary. A ¯uid loss could indicate a problem.
Check and have it repaired, if needed. Check vent
hose at transfer case for kinks and proper installation.
Transfer Case and Front Axle
(Four-Wheel Drive) Inspection
Every 12 months or at engine oil change intervals,
check front axle and transfer case and add lubricant
when necessary. A ¯uid loss could indicate a problem;
check and have it repaired, if needed. On manual
shift transfer case, oil the control lever pivot point. Check
vent hose at transfer case for kinks and proper
installation. More frequent lubrication may be required
on off-road use.
Brake System Inspection
Inspect the complete system. Inspect brake lines and
hoses for proper hook-up, binding, leaks, cracks,
cha®ng, etc. Inspect disc brake pads for wear and rotors
for surface condition. Inspect other brake parts,
including calipers, parking brake, etc. You may need to
have your brakes inspected more often if your driving
habits or conditions result in frequent braking.
6-18