
2. Repeat the burnishing procedure in Step 1 a
total of 10 times
3. Between stops, drive the vehicle about
2
1⁄2miles (4 km)
Notice:Driving with the parking brake on can
damage the transmission and brake system
parts. Verify that the parking brake is fully
released and the brake warning light is
off before driving.
Air Suspension
Your vehicle may have the Hendrickson HAS
Series single-axle air suspension which is
designed for a single-axle on-highway use. This
feature is available in 19,000 lb (8 613.3 kg),
21,000 lb (9 525.4 kg) and 23,000 lb (10 432.6 kg)
capacities.
Rear Air Suspension Dump Control
If your vehicle is equipped with the Hendrickson
HAS Series single-axle air suspension, you
may have this control. The air suspension dump
control allows the operator to lower the deck height
approximately 4.5 inches (11.5 cm) from the
normal frame height.
The switch to deflate
and inflate the air
suspension is located in
the instrument panel.
Press the bottom of the switch to deflate the air
suspension and lower the deck height. Press
the top of the switch to return the suspension to
normal deck height.
An indicator light will come on and stay on
whenever the switch is in the dumped position.
129

Four-Wheel Disc Brakes
(Hydraulic Only)
Your vehicle has four-wheel disc brakes.
Some driving conditions or climates may cause a
brake squeal when the brakes are first applied
or lightly applied. This does not mean something
is wrong with the brakes.
Brake linings should always be replaced as
complete axle sets.
Four-Wheel and Six-Wheel Drum
Brakes (Air Only)
The brake drums should be removed and
inspected each time the tires are removed for
rotation or changing. When you have the
front brakes replaced, have the rear brakes
inspected, too.
Brake linings should always be replaced as
complete axle sets.
Brake Pedal Travel
See your dealer if the brake pedal does not return
to normal height, or if there is a rapid increase in
pedal travel. This could be a sign that brake service
is needed.
Brake Adjustment
Every time you make a brake stop, the brakes
adjust for wear.
Brake Adjustment on Air Braked
Vehicles
Your vehicle has automatic slack adjusters.
Every time you make a brake stop, the brakes
automatically adjust for wear. Slack adjusters
should never be manually adjusted to correct
excessive brake chamber pushrod stroke.
Excessive brake chamber pushrod stroke means
that the brake system needs to be serviced by
a qualified service technician.
Notice:Do not manually adjust automatic slack
adjusters. Manual adjustment of the automatic
slack adjusters can result in a degradation of
the slack adjuster performance over time.
If the brake chamber pushrod stroke is out of
adjustment, the brake system needs to be
serviced by a quali ed service technician.
299

{CAUTION:
Without the correct wheel, you may not be
able to stop properly, and you could have
other problems like a tire air-out. You
could have a collision. If you do not go to
your dealer to get a new wheel, be sure
you get the correct one. Each new wheel
should match the original wheel in
load-carrying capacity, in ation pressure
capacity, diameter, width, offset and
mounting con guration.
Using wheels and tires with higher load-carrying
limits than the original wheels and tires does
not change the Gross Axle Weight Rating (GAWR)
or the Gross Vehicle Weight Rating (GVWR) of
your vehicle. SeeLoading Your Vehicle on
page 238for more information.Notice:The wrong wheel can cause trouble in
bearing life, brake cooling,
speedometer/odometer calibration, headlamp
aim, bumper height, vehicle ground clearance,
stopping distance and tire clearance to the
body and chassis. You could also have other
problems like a tire air-out.
Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You cannot know how it has
been used or how far it has been driven. It
could fail suddenly and cause a crash. If
you have to replace a wheel, use a new
GM original equipment wheel.
329

Range Inhibit Warning Indicator................... 169
Reading Lamps........................................... 154
Rear Axle.................................................... 311
Differential Lock Control........................... 215
Shift Motor............................................... 312
Two-Speed Electric Shift Control.............. 113
Rear Heating System.................................. 161
Rear Outside Passenger Positions,
Safety Belts............................................... 38
Rear Seat Operation..................................... 20
Rearview Mirrors......................................... 133
Reduced Engine Power Light...................... 179
Remote Keyless Entry (RKE) System............ 87
Remote Keyless Entry (RKE) System,
Operation................................................... 88
Reporting Safety Defects
Canadian Government............................. 414
General Motors........................................ 415
United States Government....................... 414
Restraint System Check
Checking the Restraint Systems................. 82
Replacing Restraint System Parts
After a Crash......................................... 83
Right Front Passenger Position,
Safety Belts............................................... 36
Roadside
Assistance Program................................. 408Rocking Your Vehicle to Get it Out.............. 236
Routing, Engine Drive Belt.......................... 355
Running Out of Fuel.................................... 262
Running the Engine While Parked............... 132
S
Safety Belt
Reminder Light........................................ 164
Reminder Tone........................................ 164
Safety Belts
Care of.................................................... 334
Center Passenger Position......................... 37
Driver Position........................................... 26
How to Wear Safety Belts Properly............ 26
Questions and Answers About
Safety Belts............................................ 25
Rear Outside Passenger Positions............. 38
Right Front Passenger Position.................. 36
Safety Belt Extender.................................. 41
Safety Belt Use During Pregnancy............. 36
Safety Belts Are for Everyone.................... 21
Shoulder Belt Height Adjuster.................... 35
Safety Warnings and Symbols......................... 4
Scheduled Maintenance............................... 363
Scheduled Maintenance Supplements.......... 363
427

Seats
Air Suspension Seats................................. 13
Bucket Seats............................................... 9
Rear Seat Operation.................................. 20
Split Bench Seat........................................ 13
Securing a Child Restraint
Center Rear Seat Position (Crew Cab) or
Center Front Position.............................. 60
Rear Outside Seat Position........................ 58
Right Front Seat Position........................... 63
Service........................................................ 248
California Proposition 65 Warning............. 248
Doing Your Own Work............................. 249
Engine Fan Breakage.............................. 250
Engine Soon Light................................... 174
Publications Ordering Information............. 415
Transmission Warning Light..................... 168
Servicing Your Airbag-Equipped Vehicle......... 80
Setting the Time.......................................... 185
Sheet Metal Damage................................... 337
Shoulder Belt Height Adjuster........................ 35
Signals, Turn and Lane-Change.................. 144
Sliding Rear Windows................................... 94
Snow Plow.................................................. 240
Specifications, Capacities............................ 347
Speedometer............................................... 163Split Bench Seat........................................... 13
Starting Your Diesel Engine ......................... 100
Starting Your Gasoline Engine....................... 97
Steering...................................................... 217
Steering Wheel, Tilt Wheel.......................... 142
Storage Areas............................................. 135
Center Console Storage Area................... 135
Stuck in Sand, Mud, Ice, or Snow............... 236
Sun Visors.................................................... 95
Suspension, Air........................................... 129
Switchbanks, Instrument Panel.................... 154
T
Tachometer................................................. 163
Theft-Deterrent, Radio................................. 201
Tilt Wheel.................................................... 142
Tires........................................................... 321
Aluminum or Chrome-Plated Wheels,
Cleaning............................................... 337
Cleaning.................................................. 337
Dual Tire Operation.................................. 323
If a Tire Goes Flat................................... 330
Inflation - Tire Pressure............................ 322
Tightening the Wheel Nuts....................... 325
Wheel Alignment and Tire Balance........... 324
428