2007 CHEVROLET SILVERADO power steering

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter (Gasoline Engines) on page 507.
B. Air Filter Restriction Indicator (If Equipped).
SeeEngine Air Cleaner/Filter (Gasoline
Engines) on page 507.
C. Coolant Surge Tank and Pressure Cap. See
Cooling System on page 521andCoolant
Surge Tank Pressure Cap on page 517.
D. Positive (+) Terminal. SeeJump Starting on
page 534.
E. Battery. SeeBattery on page 533.
F. Engine Oil Fill Cap. See “When to Add Engine
Oil” underEngine Oil (Gasoline Engine) on
page 502.
G. Automatic Transmission Dipstick. See
“Checking the Fluid Level” underAutomatic
Transmission Fluid on page 510.H. Remote Negative (−) Terminal (Out of View).
SeeJump Starting on page 534.
I. Engine Oil Dipstick (Out of View). See
“Checking Engine Oil” underEngine Oil
(Gasoline Engine) on page 502.
J. Engine Cooling Fan. SeeCooling System on
page 521.
K. Power Steering Fluid Reservoir. SeePower
Steering Fluid on page 526.
L. Brake Master Cylinder Reservoir. See “Brake
Fluid” underBrakes on page 529.
M. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 615.
N. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield
Washer Fluid on page 527.
501

Engine Fan Noise
If your vehicle has a clutched engine cooling fan,
when the clutch is engaged, the fan spins
faster to provide more air to cool the engine. In
most everyday driving conditions, the fan is
spinning slower and the clutch is not fully engaged.
This improves fuel economy and reduces fan
noise. Under heavy vehicle loading, trailer towing,
and/or high outside temperatures, the fan speed
increases as the clutch more fully engages, so you
may hear an increase in fan noise. This is
normal and should not be mistaken as the
transmission slipping or making extra shifts. It is
merely the cooling system functioning properly.
The fan will slow down when additional cooling is
not required and the clutch disengages.
You may also hear this fan noise when you start
the engine. It will go away as the fan clutch
partially disengages.If your vehicle has electric cooling fans, you may
hear the fans spinning at low speed during most
everyday driving. The fans may turn off if no cooling
is required. Under heavy vehicle loading, trailer
towing, and/or high outside temperatures, or if you
are operating your air conditioning system, the fans
may change to high speed and you may hear an
increase in fan noise. This is normal and indicates
that the cooling system is functioning properly. The
fans will change to low speed when additional
cooling is no longer required.
Power Steering Fluid
SeeEngine
Compartment Overview
on page 500for
reservoir location.
526

When to Check Power Steering Fluid
It is not necessary to regularly check power
steering uid unless you suspect there is a leak in
the system or you hear an unusual noise. A
uid loss in this system could indicate a problem.
Have the system inspected and repaired.
How to Check Power Steering Fluid
To check the power steering uid, do the following:
1. Turn the key off and let the engine
compartment cool down.
2. Wipe the cap and the top of the reservoir
clean.
3. Unscrew the cap and wipe the dipstick with a
clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the
uid level on the dipstick.
The level should be at the FULL COLD mark. If
necessary, add only enough uid to bring the level
up to the mark.
What to Use
To determine what kind of uid to use, see
Recommended Fluids and Lubricants on page 639.
Always use the proper uid. Failure to use the
proper uid can cause leaks and damage hoses
and seals.
Windshield Washer Fluid
What to Use
When windshield washer uid needs to be added,
be sure to read the manufacturer’s instructions
before use. Use a uid that has sufficient
protection against freezing in an area where the
temperature may fall below freezing.
527

(E) Rim Diameter:Diameter of the wheel in
inches.
(F) Service Description:The service description
indicates the load range and speed rating of a
tire. The load index can range from 1 to 279.
Speed ratings range from A to Z.
Tire Terminology and Denitions
Air Pressure:The amount of air inside the tire
pressing outward on each square inch of the
tire. Air pressure is expressed in pounds
per square inch (psi) or kilopascal (kPa).
Accessory Weight:This means the combined
weight of optional accessories. Some examples of
optional accessories are, automatic transmission,
power steering, power brakes, power windows,
power seats, and air conditioning.
Aspect Ratio:The relationship of a tire’s height
to its width.
Belt:A rubber coated layer of cords that is
located between the plies and the tread. Cords
may be made from steel or other reinforcing
materials.Bead:The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the rim.
Bias Ply Tire:A pneumatic tire in which the plies
are laid at alternate angles less than 90 degrees
to the centerline of the tread.
Cold Tire Pressure:The amount of air pressure
in a tire, measured in pounds per square inch (psi)
or kilopascals (kPa) before a tire has built up heat
from driving. SeeInation - Tire Pressure on
page 561.
Curb Weight:This means the weight of a motor
vehicle with standard and optional equipment
including the maximum capacity of fuel, oil, and
coolant, but without passengers and cargo.
DOT Markings:A code molded into the sidewall
of a tire signifying that the tire is in compliance
with the U.S. Department of Transportation (DOT)
motor vehicle safety standards. The DOT code
includes the Tire Identication Number (TIN),
an alphanumeric designator which can also identify
the tire manufacturer, production plant, brand,
and date of production.
GVWR:Gross Vehicle Weight Rating. See
Loading Your Vehicle on page 427.
558

Fuses Usage
REAR SEAT Rear Seats
AUX PWR2 Rear Accessory Power Outlet
SWC BKLT Steering Wheel Controls Backlight
DDM Driver Door Module
CTSYDome Lamps, Driver’s Side Turn
Signal
LT STOP TRN Driver Side Turn Signal, Stoplamp
DIM Instrument Panel Back Lighting
RT STOP TRNPassenger Side Turn Signal,
Stoplamp
Fuses Usage
PDMPassenger Door Module, Universal
Home Remote System
UNLCK2 Power Door Lock 2 (Unlock Feature)
LCK2 Power Door Lock 2 (Lock Feature)
STOP LAMPSStoplamps, Center-High Mounted
Stoplamp
REAR HVAC Rear Climate Controls
PWR MIR Power Mirror
BCM Body Control Module (BCM)
AUX PWR Accessory Power Outlets
IS LAMPS Interior Lamps
UNLCK1 Power Door Lock 1 (Unlock Feature)
OBS DET Ultrasonic Rear Parking Assist
LCK1 Power Door Lock 1 (Lock Feature)
REAR WPR Not Used
COOLED
SEATSNot Used
DSMDriver Seat Module, Remote
Keyless Entry System
DRV UNLCKDriver’s Power Door Lock (Unlock
Feature)
613

Circuit Breaker Usage
LT DRDriver’s Side Power Window Circuit
Breaker
Harness
ConnectorUsage
LT DR Driver’s Door Harness Connection
BODY Harness Connector
BODY Harness Connector
Center Instrument Panel Fuse Block
The center instrument panel fuse block is
located underneath the instrument panel, to the
left of the steering column.
Top View
Harness
ConnectorUsage
BODY 2 Body Harness Connector 2
BODY 1 Body Harness Connector 1
BODY 3 Body Harness Connector 3
HEADLINER 3 Headliner Harness Connector 3
HEADLINER 2 Headliner Harness Connector 2
HEADLINER 1 Headliner Harness Connector 1
614

Maintenance Footnotes
(Gasoline Engine)
This maintenance section applies to vehicles with
a gasoline engine. If your vehicle has a diesel
engine, see the maintenance schedule section in
the DURAMAX
®Diesel Engine Supplement.
†The U.S. Environmental Protection Agency or
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 the
vehicle’s useful life. We, however, urge that all
recommended maintenance services be performed
at the indicated intervals and the maintenance
be recorded.
#Lubricate the front suspension, steering linkage,
transmission shift linkage, and parking brake cable
guides. Control arm ball joints on 2500/3500 series
vehicles require lubrication but should not be
lubricated unless their temperature is
10°F (−12°C) or higher, or they could be damaged.
Control arm ball joints on 1500 series vehicles are
maintenance-free. Vehicles used under severe
commercial operating conditions require lubrication
on a regular basis every 3,000 miles (5 000 km).(a)Visually inspect brake lines and hoses for
proper hook-up, binding, leaks, cracks, chang,
etc. Inspect disc brake pads for wear and rotors for
surface condition. Inspect drum brake
linings/shoes for wear or cracks. Inspect other
brake parts, including drums, wheel cylinders,
calipers, parking brake, etc.
(b)Visually inspect front and rear suspension and
steering system for damaged, loose or missing
parts, signs of wear or lack of lubrication. Inspect
power steering lines and hoses for proper
hook-up, binding, leaks, cracks, chang, etc.
Visually check constant velocity joints, rubber
boots, and axle seals for leaks.
(c)Visually inspect hoses and have them replaced
if they are cracked, swollen, or deteriorated.
Inspect all pipes, ttings and clamps; replace with
genuine GM parts as needed. To help ensure
proper operation, a pressure test of the cooling
system and pressure cap and cleaning the outside
of the radiator and air conditioning condenser is
recommended at least once a year.
(d)Visually inspect wiper blades for wear or
cracking. Replace wiper blades that appear worn
or damaged or that streak or miss areas of
the windshield.
633

Usage Fluid/Lubricant
Hydraulic Brake
SystemDelco
®Supreme 11 Brake Fluid or
equivalent DOT-3 brake uid.
Windshield
WasherGM Optikleen
®Washer Solvent.
Power Steering
SystemGM Power Steering Fluid
(GM Part No. U.S. 89021184, in
Canada 89021186).
Automatic
TransmissionDEXRON
®-VI Automatic
Transmission Fluid.
Key Lock
CylindersMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474).
Floor Shift
LinkageLubriplate Lubricant Aerosol
(GM Part No. U.S. 12346293, in
Canada 992723) or lubricant
meeting requirements of NLGI #2
Category LB or GC-LB.
Usage Fluid/Lubricant
Chassis
LubricationChassis Lubricant
(GM Part No. U.S. 12377985, in
Canada 88901242) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Front Axle
(1500 Series)SAE 80W-90 Axle Lubricant
(GM Part No. U.S. 1052271, in
Canada 10950849).
Front Axle
(1500 HD,
2500, 2500 HD,
and 3500
Series)SAE 75W-90 Synthetic Axle
Lubricant (GM Part
No. U.S. 12378261, in
Canada 10953455) meeting
GM Specication 9986115.
Rear AxleSAE 75W-90 Synthetic Axle
Lubricant (GM Part
No. U.S. 12378261, in
Canada 10953455) meeting
GM Specication 9986115.
640