How to Add Fluid
To add transmission fluid, do the following:
1. Remove the filler plug.
2. Add fluid at the filler plug hole. Add only enough
fluid to bring the fluid level up to the bottom of
the fill opening. Refer to the Maintenance
Schedule to determine the proper fluid to use.
SeePart C: Recommended Fluids and Lubricants
on page 6-31.
3. Reinstall the filler plug. Be sure the plug is fully
seated.
Engine Coolant (Caterpillar®Diesel
Engines)
If your vehicle has a Caterpillar®diesel engine, see the
Caterpillar®Diesel Engine Operation & Maintenance
Manual provided with your vehicle to find out what to
add, as well as when and how to service your cooling
system.
Engine Coolant (Gas and
DURAMAX
®/Isuzu 7.8L L6 Engines)
The cooling system in your vehicle is filled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for five years or 150,000 miles
(240 000 km), whichever occurs first, 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 5-48.
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 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.
5-44
If No Steam Is Coming From Your
Engine
An overheat warning, along with a low coolant light, can
indicate a serious problem. SeeLow Coolant Warning
Light on page 3-35for more information.
If you get an engine overheat warning with no low
coolant light, 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.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. In heavy traffic, let the engine idle in NEUTRAL
while stopped. If it is safe to do so, pull off the
road, shift to PARK (P) or NEUTRAL and let the
engine idle.
2. Turn on your heater to full hot at the highest fan
speed and open the windows as necessary.
3. If climbing a hill, downshift to raise engine and fan
speeds.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 and you have not stopped, pull
over, stop, and park your vehicle right away.
If there is still no sign of steam, you can 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 you still have the warning, turn off the
engine and get everyone out of the vehicle until it
cools down.
You may decide not to lift the hood but to get service
help right away.
5-49
{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 there seems to be no leak, start the engine again.
The engine cooling fan speed should increase 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 the engine
without coolant is not covered by the warranty.
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.
5-51
How To Check Power Steering Fluid
Check your power steering fluid only when the engine is
warm. If the engine is not warm, you probably will not
get an accurate reading.
If the fluid level is between the MIN (Minimum) and
MAX (Maximum) marks, you have enough. If you need
fluid, add only enough of the proper fluid to bring it in
between the MIN and MAX marks.
If your power steering fluid level is low, this can cause
the brake or service brakes soon warning lights to come
on. In addition, the steering effort and emergency brake
distance could increase.
If either light remains on after you have added power
steering fluid to the proper level, then shut off the engine
for 10 seconds. This should reset the brake warning
lights. If one or both lights stay on, see “Hydraulic Brake
System Warning Lights” underBrake System Warning
Light on page 3-32for more information.
What to Use
To determine what kind of fluid to use, see
Part C: Recommended Fluids and Lubricants on
page 6-31.
Notice:When adding power steering uid or
making a complete uid change, 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 you need windshield washer fluid, be sure to read
the manufacturer’s instructions before use. If you will be
operating your vehicle in an area where the temperature
may fall below freezing, use a fluid that has sufficient
protection against freezing.
5-55
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/retailer 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
might be required.
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.
Replacing Brake System Parts
The braking system on a vehicle is complex. Its many
parts have to be of top quality and work well together if
the vehicle is to have really good braking. Your vehicle
was designed and tested with top-quality brake parts.
When you replace parts of the braking system — for
example, when the brake linings wear down and you
need new ones put in — be sure you get new approved
replacement parts. If you do not, the brakes might not
work properly. For example, if someone puts in brake
linings that are wrong for your vehicle, the balance
between the front and rear brakes can change — for the
worse. The braking performance you have come to
expect can change in many other ways if someone puts
in the wrong replacement brake parts.
5-59
Hydraulic Brake Pads
Brake pad lining life will vary depending on vehicle
application, working environment, equipment
maintenance, and style of driving. The brake pad lining
wear rate has to be monitored for individual driving
habits — original equipment linings have mechanical
wear indicators to help with this. When you are down to
the last 10% of the brake lining, the brake lining wear
indicator will rub on the rotor, causing a scratching or
chirping sound. When you hear this sound, it is time to
service the brake pads. SeeScheduled Maintenance on
page 6-5.
Aftermarket brake linings might not meet the same
stringent requirements as the original equipment linings.
Using aftermarket brake linings can affect braking
performance, pedal feel, noise, and lining wear.
Air Brake Systems
If your vehicle has air brakes, it is important to get rid of
moisture in the system. Moisture will damage the
system if it is not removed daily.
There are two ways to do this. One is automatic through
the air brake vehicle’s air dryer with integral automatic
moisture ejector that purges air from the system through
a self-contained reservoir. The other way to drain
moisture from the air brake system is to manually activate
drain valves at each reservoir. Drain the air reservoirs
occasionally to be sure the air dryer is working properly.Drain the air brakes at full system pressure. To be sure
you are at full pressure, check the air pressure gage.
It should read at least 100 psi (692 kPa).
Air Dryer
If your vehicle has air brakes, it has an air dryer
mounted on the passenger side frame rail. This collects
and removes dirt, moisture, or other foreign matter
from the air prior to entering the brake system. The dryer
also acts as a moisture ejector. It automatically ejects
the moisture when the compressor cycles. The
purge tank has a manual drain valve that must be
drained every day. See “Air Brake Systems” for the
manual drain procedure.
The dryer has a filter that you need to change at
intervals. SeeScheduled Maintenance on page 6-5for
more about servicing this filter.
Electric Air Compressor
Your vehicle might have an electric air compressor. This
compressor is used to run options that require
pressurized air, such as an air horn or air seat.
The air compressor is used when vehicles do not have
an air brake system.
5-60
The air supply for this
system must be
maintained by releasing
the drain valve to eject any
moisture that could have
built up in the system.
It is recommended that this system be drained on a
weekly basis.Clutch Pedal Free Travel
If you have a V8 engine and a manual transmission, the
clutch will need adjustment when pedal free travel gets
down to about 1/4 inch (6 mm), as measured at the clutch
pedal pad. You should have 1 1/2 to 2 inches
(38 to 51 mm) of clutch pedal free travel.
If the clutch ever needs service, be sure to use only
approved clutch replacement parts.
Chassis Lubrication
Your Maintenance Schedule provides all of the required
chassis lubrication intervals and identifies proper
lubricants to use. Be sure to see the Maintenance
Schedule before performing any chassis lubrication
service. To determine location of chassis lubrication
items, use the following charts.
5-61
8. Now connect the black negative (−) cable to the
negative (−) terminal of the good battery. Use a
remote negative (−) terminal if the vehicle has one.
Do not let the other end touch anything until the
next step. The other end of the negative (−) cable
does not go to the dead battery. It goes to a heavy,
unpainted metal engine part or to the remote
negative (−) terminal on the vehicle with the dead
battery.
9. Connect the other end of the negative (−) cable at
least 18 inches (45 cm) away from the dead battery,
but not near engine parts that move. The electrical
connection is just as good there, and the chance
of sparks getting back to the battery is much less.10. Now start the vehicle with the good battery and run
the engine for a while. Use the high idle option if
your vehicle is equipped with it.
11. Try to start the vehicle that had the dead battery. If
it will not start after a few tries, it probably needs
service.
Notice:If the jumper cables are connected or
removed in the wrong order, electrical shorting may
occur and damage the vehicle. The repairs would
not be covered by your warranty. Always connect
and remove the jumper cables in the correct
order, making sure that the cables do not touch
each other or other metal.
5-70