2. Pull out the dipstick and clean it with a paper towel
or a cloth, then push it back in all the way.
3. Remove the dipstick again, keeping the tip down,
and check the oil level.
When to Add Engine Oil
If the oil is below the cross-hatched area at the tip
of the dipstick, add at least two quarts/liters of
the recommended oil. This section explains what kind
of oil to use. For engine oil crankcase capacity, see
Capacities and Specifications on page 5-102.
Notice:Do not add too much oil. If the engine
has so much oil that the oil level gets above the
cross-hatched area that shows the proper operating
range, the engine could be damaged.Add oil at the engine oil fill
cap in the engine
compartment. Install and
fully tighten the fill cap
when you are through.
Add enough oil to put the level somewhere in the proper
operating range. Push the dipstick all the way back in
when you are through.
5-25
Engine Oil (Isuzu Diesel Engine)
Checking Engine Oil
It is a good idea to check the engine oil level every time
you get fuel.
The engine oil dipstick is
located in the engine
compartment on the driver
side of the vehicle.In order to get an accurate reading, the engine should
be at normal operating temperature, so that the oil
is warm, and the vehicle must be on level ground.
1. If the engine is at normal operating temperature and
the oil is warm, turn off the engine and allow at
least five minutes for the oil to drain back into the
oil pan. If you do not do this, the oil dipstick
might not show the actual level.
If the engine has not been run long enough to bring
it up to normal operating temperature and the oil
is cool, turn off the engine and allow 30 minutes for
the oil to drain back into the oil pan. If you do
not do this, the oil dipstick might not show the actual
level.
2. Pull out the dipstick and clean it with a paper towel
or a cloth, then push it back in all the way.
3. Remove the dipstick again, keeping the tip down,
and check the oil level.
5-28
Engine Oil (Gasoline Engine)
If the low oil light appears
on the instrument cluster,
check the engine oil
level right away.
For more information, seeLow Oil Level Light on
page 3-39. You should check the engine oil level
regularly; this is an added reminder.
Checking Engine Oil
It is a good idea to check the engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The engine oil dipstick is
located in the engine
compartment on the
driver’s side of the vehicle.
1. Turn off the engine and give the oil several minutes
to drain back into the oil pan. If you do not do this,
the oil dipstick might not show the actual level.
2. Pull out the dipstick and clean it with a paper towel
or cloth, then push it back in all the way. Remove it
again, keeping the tip down, and check the level.
5-32
Engine Oil Additives / Engine Oil
Flushes
Do not add anything to the oil. The recommended oils
with the API service symbol are all that is needed
for good performance and engine protection.
Engine oil system flushes are not recommended and
could cause engine damage not covered by the vehicle
warranty.
Engine Oil Life System (Gasoline
Engine)
When to Change Engine Oil
This vehicle has a computer system that indicates when
to change the engine oil and filter. This is based on
engine revolutions and engine temperature, and not on
mileage. Based on driving conditions, the mileage at
which an oil change is indicated can vary considerably.
For the oil life system to work properly, the system
must be reset every time the oil is changed.
When the system has calculated that oil life has been
diminished, it indicates that an oil change is necessary.
A change engine oil light comes on. SeeChangeEngine Oil Light on page 3-39. Change the oil as soon
as possible within the next 600 miles (1 000 km). It
is possible that, if driving under the best conditions, the
oil life system might not indicate that an oil change
is necessary for over a year. However, the engine oil
and filter must be changed at least once a year and at
this time the system must be reset. Your dealer/retailer
has trained service people who will perform this
work using genuine parts and reset the system. It is
also important to check the oil regularly and keep it at
the proper level.
If the system is ever reset accidentally, the oil must be
changed at 3,000 miles (5 000 km) since the last oil
change. Remember to reset the oil life system whenever
the oil is changed.How to Reset the Engine Oil Life
System
The Engine Oil Life System calculates when to change
the engine oil and filter based on vehicle use. Whenever
the oil is changed, reset the system so it can calculate
when the next oil change is required. If a situation occurs
where the oil is changed prior to a change engine oil light
being turned on, reset the system.
5-35
To reset the change engine oil light:
1. Turn the ignition key to ON/RUN with the
engine off.
2. Fully press and release the accelerator pedal slowly
three times within 10 seconds.
If the change engine oil light flashes for
five seconds, the system is resetting.
3. Turn the key to OFF.
If the change engine oil light comes back on when the
vehicle is started, the engine oil life system has not
reset. Repeat the procedure.
What to Do with Used Oil
Used engine oil contains certain elements that can be
unhealthy for your skin and could even cause cancer.
Do not let used oil stay on your skin for very long. Clean
your skin and nails with soap and water, or a good
hand cleaner. Wash or properly dispose of clothing or
rags containing used engine oil. See the manufacturer’s
warnings about the use and disposal of oil products.
Used oil can be a threat to the environment. If you
change your own oil, be sure to drain all the oil from the
filter before disposal. Never dispose of oil by putting it
in the trash, pouring it on the ground, into sewers, or into
streams or bodies of water. Recycle it by taking it to a
place that collects used oil.
Engine Oil Life System
(DURAMAX/Isuzu Diesel Engines)
When to Change Engine Oil
If the vehicle has the Engine Oil Life System, it has a
computer system that indicates when to change
the engine oil and filter. This is based on injection timing,
engine load, and engine temperature, and not on
mileage. Based on driving conditions, the mileage at
which an oil change is indicated can vary considerably.
For the oil life system to work properly, the system
must be reset every time the oil is changed.
When the system has calculated that oil life has been
diminished, it indicates that an oil change is necessary.
A change engine oil light comes on. SeeChange Engine
Oil Light on page 3-39. Change the oil as soon as
possible within the next 600 miles (1 000 km) or 30 hours
of engine operation, whichever occurs first. It is possible
that, if driving under the best conditions, the oil life system
might not indicate that an oil change is necessary for over
a year. However, the engine oil and filter must be
changed at least once a year and at this time the system
must be reset. Your dealer/retailer has trained service
people who will perform this work using genuine parts
and reset the system. It is also important to check the oil
regularly and keep it at the proper level.
5-36
Automatic Transmission Fluid
When to Check
A good time to check your automatic transmission fluid
level is when the engine oil is checked. See your
Allison Automatic Transmission Operator’s Manual to
find out when to change your transmission fluid
and filters.
How to Check and What to Use
The Allison Automatic Transmission Operator’s Manual
that came with the vehicle shows how to check the
automatic transmission fluid and what fluid to use.
Automatic Transmission External Filter
Your automatic transmission filter requires periodic
replacement.
Consult the Allison Automatic Transmission Operator’s
Manual that came with the vehicle for proper change
intervals.
Manual Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
checked. Refer to the Maintenance Schedule to find out
when to check and change your manual transmission
fluid. SeeScheduled Maintenance on page 6-5.
How to Check and What to Use
Check the fluid level only when your engine is off, the
vehicle is parked on a level place, and the transmission
is cool enough for you to rest your fingers on the
transmission case.
To check the transmission fluid level, do the following:
1. Remove the filler plug.
2. Check to be sure that the lubricant level is up
to the bottom of the fill opening. On heavy duty
transmissions, an inch of oil level equals about
one gallon of fluid.
3. If the fluid level is good, reinstall the plug and be
sure it is fully seated. If the fluid level is low, add
more fluid as described in the next steps. Refer to
the Maintenance Schedule to determine what
kind of fluid to use. SeePart C: Recommended
Fluids and Lubricants on page 6-31.
5-42
The coolant level should
be at the FULL COLD
mark or higher. 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 fire, and you could be burned.
Get any leak fixed 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 can
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 first. Any repairs
would not be covered by the vehicle warranty.
Always use DEX-COOL (silicate-free) coolant in
your vehicle.
How to Add Coolant to the Coolant
Surge Tank
If you have not found a problem yet, check to see if
coolant is visible in the surge tank. If coolant is visible
but the coolant level is not at the FULL COLD mark
or higher, add a 50/50 mixture of clean, drinkable water
and DEX-COOL
®coolant at the coolant surge tank,
but be sure the cooling system, including the coolant
surge tank pressure cap, is cool before you do it.
SeeEngine Coolant (Caterpillar Diesel Engines) on
page 5-47for more information.
5-44
Engine Overheating
You will find an engine coolant temperature gage, as
well as a low coolant warning light, on your vehicle’s
instrument panel. SeeEngine Coolant Temperature
Gage on page 3-34andLow Coolant Warning Light on
page 3-35for more information.
Your vehicle also has a check gages warning light on
the instrument panel. SeeCheck Gages Warning
Light on page 3-43for more information.
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. Just 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.
CAUTION: (Continued)
CAUTION: (Continued)
If you keep driving when your engine is overheated,
the liquids in it can catch fire. You or others could
be badly burned. Stop your engine if it overheats,
and get out of the vehicle until the engine is cool.
Notice:If the engine catches fire because of being
driven with no coolant, your vehicle can be badly
damaged. The costly repairs would not be covered
by the vehicle warranty.
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.
5-48