GMC SIERRA CLASSIC 2007 Owners Manual

How to Add Manual Transmission Fluid
Here is how to add uid. Refer to the Maintenance
Schedule to determine what kind of uid to
use. SeeRecommended Fluids and Lubricants on
page 629.
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 will not 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. SeeEngine
Compartment Overview
on page 480for 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. SeeOwner Checks and Services
on page 625andRecommended Fluids and
Lubricants on page 629.
501

How to Check and Add Fluid
The proper uid should be added if the level does
not reach the bottom of the diaphragm when it
is in place in the reservoir. See the instructions on
the reservoir cap.
Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is
designed to remain in your vehicle for ve years
or 150,000 miles (240 000 km), whichever
occurs rst, if you add only DEX-COOL
®
extended life coolant.
The following explains your cooling system and
how to add coolant when it is low. If you have
a problem with engine overheating, seeEngine
Overheating on page 505.A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down
to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®
may cause premature engine, heater core,
or radiator corrosion. In addition, the engine
coolant may require changing sooner, at
the rst maintenance service after each
30,000 miles (50 000 km) or 24 months,
whichever occurs rst. Any repairs would not
be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your
vehicle.
502

What to Use
Use a mixture of one-half clean, drinkable water
and one-half DEX-COOL®coolant which will
not damage aluminum parts. If you use this coolant
mixture, you do not need to add anything else.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can
boil before the proper coolant mixture will.
Your vehicle’s coolant warning system is
set for the proper coolant mixture. With
plain water or the wrong mixture, your
engine could get too hot but you would
not get the overheat warning. Your engine
could catch re and you or others could
be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.Notice:If you use an improper coolant
mixture, your engine could overheat and be
badly damaged. The repair cost would not be
covered by your warranty. Too much water
in the mixture can freeze and crack the engine,
radiator, heater core, and other parts.
If you have to add coolant more than four times a
year, have your dealer check your cooling
system.
Notice:If you use extra inhibitors and/or
additives in your vehicle’s cooling system,
you could damage your vehicle. Use only the
proper mixture of the engine coolant listed
in this manual for the cooling system.
SeeRecommended Fluids and Lubricants
on page 629for more information.
503

Checking Coolant
The coolant surge tank is located in the engine
compartment on the passenger’s side of the
vehicle. SeeEngine Compartment Overview on
page 480for more information on location.
{CAUTION:
Turning the surge tank pressure cap when
the engine and radiator are hot can allow
steam and scalding liquids to blow out
and burn you badly. Never turn the surge
tank pressure cap — even a little — when
the engine and radiator are hot.The vehicle must be on a level surface. When
your engine is cold, the coolant level should be at
the FULL COLD mark.
If your vehicle is equipped with a low coolant
sensor and the LOW COOLANT LEVEL message
comes on and stays on, it means you are low
on engine coolant. See “LOW COOLANT LEVEL”
underDIC Warnings and Messages on page 270.
504

Adding Coolant
If you need more coolant, add the proper
DEX-COOL®coolant mixture at the surge tank,
but only when the engine is cool. SeeCooling
System on page 508.
{CAUTION:
You can be burned if you spill coolant
on hot engine parts. Coolant contains
ethylene glycol, and it will burn if the
engine parts are hot enough. Do not spill
coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight and fully seated.
Coolant Surge Tank Pressure Cap
Notice:If the pressure cap is not tightly
installed, coolant loss and possible engine
damage may occur. Be sure the cap is properly
and tightly secured.
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. SeeEngine
Compartment Overview on page 480for more
information on location.
Engine Overheating
You will nd a coolant temperature gage on your
vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 256.
In addition, you will nd an ENGINE
OVERHEATED and a REDUCED ENGINE
POWER message in the Driver Information
Center (DIC) on the instrument panel. SeeDIC
Warnings and Messages on page 270.
505

If Steam Is Coming From Your Engine
{CAUTION:
Steam from an overheated engine can
burn you badly, even if you just open the
hood. Stay away from the engine if you
see or hear steam coming from it. Turn
it off and get everyone away from the
vehicle until it cools down. Wait until
there is no sign of steam or coolant
before you open the hood.
If you keep driving when the vehicles
engine is overheated, the liquids in it can
catch re. You or others could be badly
burned. Stop your engine if it overheats,
and get out of the vehicle until the engine
is cool.
CAUTION: (Continued)
CAUTION: (Continued)
SeeOverheated Engine Protection
Operating Mode (V8 Engines Only) on
page 508for information on driving to a
safe place in an emergency.
Notice:If your engine catches re because
you keep driving with no coolant, your vehicle
can be badly damaged. The costly repairs
would not be covered by your warranty. See
Overheated Engine Protection Operating Mode
(V8 Engines Only) on page 508for information
on driving to a safe place in an emergency.
506

If No Steam Is Coming From Your
Engine
The ENGINE COOLANT HOT message, along
with a low coolant condition, can indicate a serious
problem.
If you get an engine overheat warning, but see or
hear no steam, the problem may not be too
serious. Sometimes the engine can get a little too
hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer. SeeTowing a Trailer on
page 429.
If you get the ENGINE COOLANT HOT message
with no sign of steam, try this for a minute or so:
1. If your air conditioner is on, turn it off.
2. Turn on your heater to full hot at the highest
fan speed and open the windows as
necessary.
3. If you are in a traffic jam, shift to
NEUTRAL (N); otherwise, shift to the highest
gear while driving — DRIVE (D) or THIRD (3).If you no longer have the overheat warning, you
can drive. Just to be safe, drive slower for
about 10 minutes. If the warning does not come
back on, you can drive normally.
If the warning continues, pull over, stop, park, and
fast idle your vehicle right away.
If there is still no sign of steam and your vehicle
is equipped with an engine-driven cooling fan,
push down the accelerator until the engine speed
is about twice as fast as normal idle speed for
at least three minutes while you are parked.
If there is still no sign of steam and your vehicle is
equipped with an electric engine cooling fan, idle
the engine for three minutes while you are parked.
If you still have the warning, turn off the engine
and get everyone out of the vehicle until it
cools down. Also, see “Overheated Engine
Protection Operating Mode” later in this section.
You may decide not to lift the hood but to get
service help right away.
507

Overheated Engine Protection
Operating Mode (V8 Engines Only)
If an overheated engine condition exists and
the REDUCED ENGINE POWER message
is displayed, an overheat protection mode which
alternates ring groups of cylinders helps
prevent engine damage. In this mode, you will
notice a loss in power and engine performance.
This operating mode allows your vehicle to
be driven to a safe place in an emergency. Driving
extended miles (km) and/or towing a trailer in
the overheat protection mode should be avoided.
Notice:After driving in the overheated
engine protection operating mode, to avoid
engine damage, allow the engine to cool before
attempting any repair. The engine oil will be
severely degraded. Repair the cause of coolant
loss, change the oil and reset the oil life
system. SeeEngine Oil (Gasoline Engine) on
page 486.
Cooling System
When you decide it is safe to lift the hood, here is
what you will see:
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan
8.1L V8 Engines
508

A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan
{CAUTION:
An electric fan under the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing, and tools
away from any underhood electric fan.
If the coolant inside the coolant surge tank is
boiling, do not do anything else until it cools down.
The vehicle should be parked on a level surface.
Check the coolant level after the system cools
down. Some amount of coolant may be lost due to
overheating.
All Other Engines
509

The coolant level should
be at or above the FULL
COLD mark. If it is not,
you may have a leak at
the pressure cap or in
the radiator hoses,
heater hoses, radiator,
water pump, or
somewhere else in the
cooling system.
{CAUTION:
Heater and radiator hoses, and other
engine parts, can be very hot. Do not
touch them. If you do, you can be burned.
Do not run the engine if there is a leak.
If you run the engine, it could lose all
coolant. That could cause an engine re,
and you could be burned. Get any leak
xed before you drive the vehicle.If your vehicle has an electric engine cooling
fan, check the coolant temperature gage.
If the coolant temperature is approximately
232°F (111°C), the electric cooling fan should be
running. If it is not, your vehicle needs service.
Turn off the engine.
If your vehicle has an engine-driven cooling fan,
start the engine again and see if the fan speed
increases when idle speed is doubled by pushing
the accelerator pedal down. If it does not, your
vehicle needs service. Turn off the engine.
Notice:Engine damage from running your
engine without coolant is not covered by your
warranty. SeeOverheated Engine Protection
Operating Mode (V8 Engines Only) on page 508
for information on driving to a safe place in
an emergency.
Notice:Using coolant other than DEX-COOL®
may cause premature engine, heater core or
radiator corrosion. In addition, the engine
coolant may require changing sooner, at
30,000 miles (50 000 km) or 24 months,
whichever occurs rst. Any repairs would not
be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your
vehicle.
510