2004 GMC SIERRA clutch

·Never go downhill with the transmission in
NEUTRAL (N), or with the clutch pedal pressed
down in a manual shift. This is called
ªfree-wheeling.º Your brakes will have to do all the
work and could overheat and fade.
Q:Am I likely to stall when going downhill?
A:It is much more likely to happen going uphill. But if
it happens going downhill, here is what to do.
·Stop your vehicle by applying the regular brakes.
Apply the parking brake.
·Shift to PARK (P) (or to neutral with the manual
transmission) and, while still braking, restart the
engine.
·Shift back to a low gear, release the parking brake,
and drive straight down.
·If the engine will not start, get out and get help.
Driving Across an Incline
Sooner or later, an off-road trail will probably go across
the incline of a hill. If this happens, you have to
decide whether to try to drive across the incline. Here
are some things to consider:
·A hill that can be driven straight up or down may be
too steep to drive across. When you go straight up
or down a hill, the length of the wheel base (the
distance from the front wheels to the rear wheels)
reduces the likelihood the vehicle will tumble
end over end. But when you drive across an incline,
the much more narrow track width (the distance
between the left and right wheels) may not prevent
the vehicle from tilting and rolling over. Also,
driving across an incline puts more weight on the
downhill wheels. This could cause a downhill
slide or a rollover.
·Surface conditions can be a problem when you
drive across a hill. Loose gravel, muddy spots,
or even wet grass can cause your tires to slip
sideways, downhill. If the vehicle slips sideways,
it can hit something that will trip it (a rock, a rut, etc.)
and roll over.
·Hidden obstacles can make the steepness of the
incline even worse. If you drive across a rock with the
uphill wheels, or if the downhill wheels drop into a rut
or depression, your vehicle can tilt even more.
4-32

Power Winches
If you wish to use a power winch on your vehicle, only
use it when your vehicle is stationary or anchored.
Power Take-Off (PTO)
Before using a PTO, if equipped, refer to the
manufacturer's or installer's instructions.
To engage a PTO on a vehicle with a manual
transmission do the following:
1. Hold the clutch pedal down.
2. Set the parking brake.
3. Shift the transmission into NEUTRAL (N).
4. Engage the PTO. Refer to the manufacturer's or
installer's for instructions on electrically
engaged PTOs.
5. For mobile operations, shift the transmission into
the gear you want, apply the regular brakes and
release the parking brake. For stationary operations,
leave the parking brake applied.
6. Release the clutch and regular brakes as you
normally would. When the clutch is released,
the PTO will start.
7. Turn the PTO rotary switch to ON.To engage a PTO on a vehicle with an automatic
transmission do the following:
1. For stationary use shift the transmission into
PARK (P).
2. Turn the PTO rotary switch ON.
3. If the engine speed is below the PTO engage
speed limit, the PTO will start. The blinking LED
on the PTO control switch indicates PTO engage is
requested. When PTO engages the LED will
switch from blinking to a steady light.
To use PTO speed control in Preset Mode (Factory
Setting) do the following:
1. Engage the PTO
2. Select PARK (P) or NEUTRAL (N) range. Apply the
parking brake if NEUTRAL (N) is selected. Torque
Converter Clutch (TCC) is not available in
NEUTRAL (N) and is available only in PARK (P)
when engine speed is above 1,100 rpm.
3. Make sure your foot is off the brake pedal (and off
the clutch on vehicles equipped with a manual
transmission).
4. Select the desired engine speed for PTO operation.
Read the following preset mode information
regarding operation.
4-101

Preset Mode:PTO speed control mode is used for
stationary applications. (PTO will remain engaged while
mobile in the preset mode, however PTO set and
resume speed controls will be inoperative). This mode
provides a default standby speed of 800 or 850 rpm
(depending on the engine/transmission combination) and
two default PTO control speeds which follow:
1. PTO Set Speed of 1,250 rpm, or
2. PTO Resume Speed of 1,700 rpm.
Please note that the standby speed (800/850 rpm) is
not to be used as a PTO control speed. Vehicles
not equipped with cruise control will not have the resume
speed capability.
To use PTO speed control in variable mode (while
mobile) do the following:
1. Engage the PTO.
2. Vehicle speed must be greater than 5 mph.
3. Make sure your foot is off the brake pedal (and off
the clutch for vehicles equipped with a manual
transmission).
4. Select the desired engine speed by using the foot
pedal, and select SET on the PTO switch or the
cruise control.To use PTO speed control in variable mode (while
stationary) do the following:
1. Engage the PTO.
2. Vehicle speed must be less than 5 mph.
3. Make sure your foot is off the brake pedal (and off
the clutch for vehicles equipped with a manual
transmission).
4. Select the desired engine speed by using the foot
pedal, and select SET on the PTO switch or the
cruise control.
Variable Mode:PTO speed control mode can be used
for both stationary and mobile applications. This
mode allows PTO to be controlled in a fashion similar to
how cruise control sets vehicle speed. The operator
can set to an rpm (between 800 and 2,200) with
the cruise control feature or with the SET position on
the PTO switch. The operator is then able to increase
rpm in increments of 100, or²tap up²with the resume
position on the cruise control. Or, the operator can
decrease rpm in increments of 100 with the SET switch
on the PTO or the cruise control.Vehicles not
equipped with cruise control will not have the ªtap
upº capability..
4-102

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the Outside of Your
Vehicle......................................................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-4
Gasoline Speci®cations....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-6
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood....................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-18
Engine Air Cleaner/Filter................................5-23
Automatic Transmission Fluid (Except Allison
Transmission
ž) ..........................................5-25
Automatic Transmission Fluid (Allison
Transmission
ž) ..........................................5-28
Manual Transmission Fluid.............................5-31
Hydraulic Clutch...........................................5-32
Engine Coolant.............................................5-33
Coolant Surge Tank Pressure Cap..................5-36
Engine Overheating.......................................5-36Cooling System............................................5-39
Engine Fan Noise.........................................5-44
Power Steering Fluid.....................................5-45
Windshield Washer Fluid................................5-46
Brakes........................................................5-48
Battery........................................................5-52
Jump Starting...............................................5-53
Rear Axle.......................................................5-59
Four-Wheel Drive............................................5-60
Noise Control System.....................................5-62
Tampering with Noise Control System
Prohibited.................................................5-62
Bulb Replacement..........................................5-64
Halogen Bulbs..............................................5-64
Headlamps..................................................5-64
Front Turn Signal, Sidemarker and Daytime
Running Lamps.........................................5-66
Roof Marker Lamps......................................5-67
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp.............................................5-69
Pickup Box Identi®cation and Fender Marker
Lamps.....................................................5-70
Taillamps.....................................................5-71
Replacement Bulbs.......................................5-74
Section 5 Service and Appearance Care
5-1

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-23.
B. Coolant Surge Tank. See
Engine Coolant on
page 5-33.
C. Air Filter Restriction Indicator (If Equipped). See
Engine Air Cleaner/Filter on page 5-23.
D. Engine Oil Dipstick. See
Engine Oil on page 5-18.
E. Automatic Transmission Dipstick (If equipped).
See
Automatic Transmission Fluid (Except Allison
Transmissionž) on page 5-25orAutomatic
Transmission Fluid (Allison Transmissionž)on
page 5-28.
F. Fan. See
Cooling System on page 5-39.
G. Engine Oil Fill. See
Engine Oil on page 5-18.H. Power Steering Fluid Reservoir. See
Power Steering
Fluid on page 5-45.
I. Remote Negative (-) Terminal (GND). See
Jump
Starting on page 5-53.
J. Remote Positive (+) Terminal. See
Jump Starting on
page 5-53.
K. Brake Fluid Reservoir. See
Brakes on page 5-48.
L. Clutch Fluid Reservoir (If Equipped). See
Hydraulic
Clutch on page 5-32.
M. Underhood Fuse Block. See
Fuses and Circuit
Breakers on page 5-126.
N. Battery. See
Battery on page 5-52.
O. Windshield Washer Fluid Reservoir. See
Windshield
Washer Fluid on page 5-46.
5-13

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-23.
B. Coolant Surge Tank. See
Engine Coolant on
page 5-33.
C. Air Filter Restriction Indicator (If Equipped). See
Engine Air Cleaner/Filter on page 5-23.
D. Engine Oil Dipstick. See
Engine Oil on page 5-18.
E. Automatic Transmission Dipstick (If Equipped).
See
Automatic Transmission Fluid (Except Allison
Transmissionž) on page 5-25orAutomatic
Transmission Fluid (Allison Transmissionž)on
page 5-28.
F. Engine Oil Fill. See
Engine Oil on page 5-18.
G. Fan. See
Cooling System on page 5-39.H. Remote Negative (-) Terminal (GND). See
Jump
Starting on page 5-53.
I. Power Steering Fluid Reservoir. See
Power Steering
Fluid on page 5-45.
J. Remote Positive (+) Terminal. See
Jump Starting on
page 5-53.
K. Brake Fluid Reservoir. See
Brakes on page 5-48.
L. Clutch Fluid Reservoir (If Equipped). See
Hydraulic
Clutch on page 5-32.
M. Underhood Fuse Block. See
Fuses and Circuit
Breakers on page 5-126.
N. Battery. See
Battery on page 5-52.
O. Windshield Washer Fluid Reservoir. See
Windshield
Washer Fluid on page 5-46.
5-15

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-23.
B. Coolant Surge Tank. See
Engine Coolant on
page 5-33.
C. Air Filter Restriction Indicator (If Equipped). See
Engine Air Cleaner/Filter on page 5-23.
D. Engine Oil Dipstick. See
Engine Oil on page 5-18.
E. Automatic Transmission Dipstick (If Equipped).
See
Automatic Transmission Fluid (Except Allison
Transmissionž) on page 5-25orAutomatic
Transmission Fluid (Allison Transmissionž)on
page 5-28.
F. Engine Oil Fill. See
Engine Oil on page 5-18.
G. Fan. See
Cooling System on page 5-39.H. Remote Negative (-) Terminal (GND). See
Jump
Starting on page 5-53.
I. Remote Positive (+) Terminal. See
Jump Starting on
page 5-53.
J. Power Steering Fluid Reservoir. See
Power Steering
Fluid on page 5-45.
K. Brake Fluid Reservoir. See
Brakes on page 5-48.
L. Clutch Fluid Reservoir (If Equipped). See
Hydraulic
Clutch on page 5-32.
M. Underhood Fuse Block. See
Fuses and Circuit
Breakers on page 5-126.
N. Battery. See
Battery on page 5-52.
O. Windshield Washer Fluid Reservoir. See
Windshield
Washer Fluid on page 5-46.
5-17

How to Add Fluid
Here's how to add ¯uid. Refer to the Maintenance
Schedule to determine what kind of ¯uid to use. See
Recommended Fluids and Lubricants on page 6-14.
1. Remove the ®ller plug.
2. Add ¯uid at the ®ller plug hole. Add only enough
¯uid to bring the ¯uid level up to the bottom of the
®ller plug hole.
3. Install the ®ller plug. Be sure the plug is fully
seated.
Hydraulic Clutch
The hydraulic clutch linkage in your vehicle is
self-adjusting. The clutch master cylinder reservoir is
®lled with hydraulic clutch ¯uid.
It is not necessary to regularly check clutch ¯uid unless
you suspect there is a leak in the system. Adding
¯uid won't correct a leak.
A ¯uid loss in this system could indicate a problem.
Have the system inspected and repaired.
When to Check and What to Use
The clutch master cylinder
reservoir is located in the
rear of the engine
compartment on the
driver's side of the vehicle.
See
Engine Compartment
Overview on page 5-12
for more information
on location.
Refer to the Maintenance Schedule to determine how
often you should check the ¯uid level in your clutch
master cylinder reservoir and for the proper ¯uid. See
Owner Checks and Services on page 6-10andRecommended Fluids and Lubricants on page 6-14.
5-32