1999 GMC C-SERIES height adjustment

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1-4 National Seats (If Equipped)
If your vehicle has the low-back National seat, there are
six ways you can adjust the seat.
If your vehicle has the high
-back National seat, there are
five ways you can adjust the seat.Height Adjustment
To adjust the height of a
self
-contained seat
(hand
-pumped air seat),
push the seat height
adjustment pump lever,
located on the lower
outboard side, down and
continue pumping to raise
the seat. Press the lever and
hold it to lower the seat.
To adjust the height of air
-sourced seats, use the knob
on the front left
-hand side on the seat. Push the knob to
inflate. Pull the knob to deflate.
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1-5
To adjust the height of the
cushion, lift the cushion
height adjustment handle up
and forward. You can
choose between two
settings. The handle is
located underneath the seat,
in the front.
Lumbar Adjustments
To get more support in the
lumbar area of your back,
turn the lumbar adjustment
knob. The knob is located
on the upper cushion, on the
inboard side of the driver's
seat and the outboard side
of the passenger's seat.Seatback Adjustment
To tilt the seatback, turn the
backrest tilt knob. The knob
is located on the lower
cushion, on the outboard
side of the driver's seat and
the inboard side of the
passenger's seat.
Fore
-and-Aft Adjustment
To slide the seat forward or
backward, move the lever
toward the passenger's side.
The seat will lock in at
1/2 inch (1.5 cm)
increments. The lever is
located underneath the seat,
in the front.
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6-33 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 of brake trouble.
Brake Adjustment
Every time you make a brake stop, your brakes adjust
for wear.
Air Brake Systems (If Equipped)
If you have air brakes, it is important to get rid of
moisture in the system. Moisture will damage your
system if it isn't removed daily.There are two ways to do this. One is automatic if your
air
-brake vehicle has the optional moisture ejector. If
your vehicle doesn't have that option, however, you
must drain the air reservoirs every day.
Drain them at full system
pressure. To be sure you're
at full pressure, check
your air pressure gage.
It should read at least
100 psi (692 kPa).
Moisture Ejector (Option)
If you have air brakes with a moisture ejector, the valve
automatically ejects moisture from the reserve tank
when the air compressor cycles.
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9-8
Safety Belts 1-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adults 1-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Care 6-61 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Center Passenger Position 1-22 . . . . . . . . . . . . . . . . . . . . . .
Children 1-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Driver Position 1-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Extender 1-36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How to Wear Properly 1-11 . . . . . . . . . . . . . . . . . . . . . . . . .
Lap Belt 1-22 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lap-Shoulder Belt 1-12 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Larger Children 1-33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Questions and Answers 1-10 . . . . . . . . . . . . . . . . . . . . . . . .
Reminder Light 1-7, 2-55 . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing After a Crash 1-36 . . . . . . . . . . . . . . . . . . . . . . . .
Right Passenger Position 1-21 . . . . . . . . . . . . . . . . . . . . . . .
Smaller Children and Babies 1-23 . . . . . . . . . . . . . . . . . . . .
Use During Pregnancy 1-21 . . . . . . . . . . . . . . . . . . . . . . . . .
Why They Work 1-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safety Defects, Reporting 8-6, 8-7 . . . . . . . . . . . . . . . . . . . . .
Safety Warnings and Symbols iii. . . . . . . . . . . . . . . . . . . . . . .
Scheduled Maintenance 7
-5 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Scheduled Maintenance Services 7-4 . . . . . . . . . . . . . . . . . . . .
Seat Adjuster Check 7-26 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Seatback Latches 1-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Seats
Bucket and Bench 1
-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chugger-Snubber Lock-Out 1-6 . . . . . . . . . . . . . . . . . . . . .
Controls 1-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cushion Adjustment 1-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fore-and-Aft Adjustment 1-5 . . . . . . . . . . . . . . . . . . . . . . . Height Adjustment 1
-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lumbar Adjustments 1-5 . . . . . . . . . . . . . . . . . . . . . . . . . . .
National 1-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Securing a Child Restraint 1-31 . . . . . . . . . . . . . . . . . . . . . . . .
Service 6-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bulletins, Ordering 8-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manuals, Ordering 8-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Park Brake Warning Light 2-60 . . . . . . . . . . . . . . . . . . . . . .
Parts Identification Label 6-67 . . . . . . . . . . . . . . . . . . . . . . .
Publications, Ordering 8-8 . . . . . . . . . . . . . . . . . . . . . . . . . .
Trans Filter Indicator Light 2-64 . . . . . . . . . . . . . . . . . . . . .
Work, Doing Your Own 6-3 . . . . . . . . . . . . . . . . . . . . . . . . .
Service and Appearance Care 6-1 . . . . . . . . . . . . . . . . . . . . . .
Service and Owner Publications 8-8 . . . . . . . . . . . . . . . . . . . .
Sheet Metal Damage 6-64 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Signal-Stat Turn Signal 2-33, 5-4 . . . . . . . . . . . . . . . . . . . . . .
Skidding 4-14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications, Engine 6-74 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Speedometer 2-53 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starter Switch Check 7-25 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starting Your Diesel Engine 2-10 . . . . . . . . . . . . . . . . . . . . . . .
Starting Your Gasoline Engine 2-7 . . . . . . . . . . . . . . . . . . . . . .
Steam 5-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering 4-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Check 7-25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
In Emergencies 4-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power 4-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tips 4-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wheel, Tilt 2-31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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