Page 777 of 871

Engine Coolant Checks
Check the engine coolant (antifreeze) protection every 12
months (before the onset of freezing weather, where
applicable). If the engine coolant (antifreeze) is dirty or
rusty in appearance, the system should be drained,
flushed and refilled with fresh coolant. Check the front of
the A/C condenser (if equipped) or radiator for any
accumulation of bugs, leaves, etc. If dirty, clean by gently
spraying water from a garden hose vertically down the
face of the A/C condenser (if equipped) or the back of the
radiator core.
Check the engine cooling system hoses for brittle rubber,
cracking, tears, cuts and tightness of the connection at the
coolant recovery bottle and radiator. Inspect the entire
system for leaks.
With the engine at normal operating temperature (but
not running), check the cooling system pressure cap for
proper vacuum sealing by draining a small amount of
engine coolant (antifreeze) from the radiator drain cock.
The radiator drain cock is located in the lower radiator
tank. If the cap is sealing properly, the engine coolant
(antifreeze) will begin to drain from the coolant expan-
sion bottle. DO NOT REMOVE THE COOLANT PRES-
SURE CAP WHEN THE COOLING SYSTEM IS HOT.
Cooling System — Drain Flush And Refill
If the engine coolant (antifreeze) is dirty or contains a
considerable amount of sediment, clean and flush with a
reliable cooling system cleaner. Follow with a thorough
rinsing to remove all deposits and chemicals. Properly
dispose of old engine coolant (antifreeze).
Refer to the “Maintenance Schedule” for the proper
maintenance intervals.
7
MAINTAINING YOUR VEHICLE 775
Page 780 of 871

Cooling System Pressure Cap
The cap must be fully tightened to prevent loss of engine
coolant (antifreeze), and to ensure that the engine coolant
(antifreeze) will return to the radiator from the coolant
expansion bottle.
The cap should be inspected and cleaned if there is any
accumulation of foreign material on the sealing surfaces.
WARNING!
•Do not open hot engine cooling system. Never add
engine coolant (antifreeze) when the engine is
overheated. Do not loosen or remove the cap to cool
an overheated engine. Heat causes pressure to
build up in the cooling system. To prevent scalding
or injury, do not remove the pressure cap while the
system is hot or under pressure.
(Continued)
WARNING!(Continued)
•Do not use a pressure cap other than the one
specified for your vehicle. Personal injury or en-
gine damage may result.
Disposal Of Used Engine Coolant
Used ethylene glycol-based engine coolant (antifreeze) is
a regulated substance requiring proper disposal. Check
with your local authorities to determine the disposal
rules for your community. To prevent ingestion by ani-
mals or children, do not store ethylene glycol-based
engine coolant (antifreeze) in open containers or allow it
to remain in puddles on the ground. If ingested by a child
or pet, seek emergency assistance immediately. Clean up
any ground spills immediately.
778 MAINTAINING YOUR VEHICLE
Page 781 of 871
Checking Coolant Level — 3.6L and 5.7L Engines
With the engine OFF and cold, the level of the engine
coolant should be between the ADD and SAFE range on
the dipstick.
To check the coolant level:
1. Open the coolant reservoir.
2. Lift and remove the plastic dipstick from the reservoir
neck.
Opening The Coolant Reservoir
7
MAINTAINING YOUR VEHICLE 779
Page 782 of 871

3. Check the coolant level on the dipstick.
The radiator normally remains completely full, so there is
no need to remove the radiator cap unless checking for
engine coolant (antifreeze) freeze point or replacing engine
coolant (antifreeze). Advise your service attendant of this.
As long as the engine operating temperature is satisfactory,
the coolant bottle need only be checked once a month.
When additional engine coolant (antifreeze) is needed to
maintain the proper level, it should be added to the
coolant bottle. Do not overfill.
Checking Coolant Level — 6.4L Engine
The level of the coolant in the pressurized coolant bottle
should be between the “MIN” and “MAX” range on the
bottle when the engine is cold.
The radiator normally remains completely full, so there is
no need to remove the cap unless checking for coolant
freeze point or replacing engine coolant (antifreeze).
Advise your service attendant of this. As long as the
engine operating temperature is satisfactory, the coolant
bottle need only be checked once a month. When addi-
tional engine coolant (antifreeze) is needed to maintain
the proper level, it should be added to the coolant bottle.
Do not overfill.
Coolant Reservoir Dipstick
780 MAINTAINING YOUR VEHICLE
Page 783 of 871

Points To Remember
NOTE:When the vehicle is stopped after a few miles/
kilometers of operation, you may observe vapor coming
from the front of the engine compartment. This is nor-
mally a result of moisture from rain, snow, or high
humidity accumulating on the radiator and being vapor-
ized when the thermostat opens, allowing hot engine
coolant (antifreeze) to enter the radiator.
If an examination of your engine compartment shows no
evidence of radiator or hose leaks, the vehicle may be
safely driven. The vapor will soon dissipate.
•Do not overfill the coolant expansion bottle.
•Check the coolant freeze point in the radiator and in the
coolant expansion bottle. If engine coolant (antifreeze)
needs to be added, the contents of the coolant expansion
bottle must also be protected against freezing.
•If frequent engine coolant (antifreeze) additions are
required, the cooling system should be pressure tested
for leaks.
•Maintain engine coolant (antifreeze) concentration at a
minimum of 50% OAT coolant (conforming to MS-12106)
and distilled water for proper corrosion protection of
your engine which contains aluminum components.
•Make sure that the coolant expansion bottle overflow
hoses are not kinked or obstructed.
•Keep the front of the radiator clean. If your vehicle is
equipped with air conditioning, keep the front of the
condenser clean.
•Do not change the thermostat for Summer or Winter
operation. If replacement is ever necessary, install
ONLY the correct type thermostat. Other designs may
result in unsatisfactory engine coolant (antifreeze)
performance, poor gas mileage, and increased emis-
sions.
7
MAINTAINING YOUR VEHICLE 781
Page 790 of 871

Use the following procedure to check the transmission
fluid level properly:
1. Monitor the transmission temperature using the
EVIC/DID screen, and operate the vehicle as required
to reach the normal operating temperature. If the
transmission is not functioning properly, or the vehicle
cannot be driven, see the NOTE and CAUTION below
about checking the fluid level at colder temperatures.
2. Park the vehicle on level ground.
3. Run the engine at normal idle speed for at least 60
seconds, and leave the engine running for the rest of
this procedure.
4. Fully apply the parking brake, and press the brake
pedal.
5.Place the shift lever momentarily into each gear position
(allowing time for the transmission to fully engage in
each position), ending with the transmission in PARK.
6. Remove the dipstick, wipe it clean and reinsert it until
seated.
7. Remove the dipstick again and note the fluid level on
both sides. The fluid level reading is only valid if there
is a solid coating of oil on both sides of the dipstick.
Note that the holes in the dipstick will be full of fluid
if the actual level is at or above the hole. The fluid level
should be between the “HOT” (upper) reference holes
on the dipstick at normal operating temperature. If the
fluid level is low, add fluid through the dipstick tube
to bring it to the proper level.Do not overfill.Use
ONLY the specified fluid (see#Fluids, Lubricants, and
Genuine Parts#for fluid specifications). After adding
any quantity of oil through the dipstick tube, wait a
minimum of two minutes for the oil to fully drain into
the transmission before rechecking the fluid level.
788 MAINTAINING YOUR VEHICLE
Page 791 of 871

NOTE:If it is necessary to check the transmissionbelow
the operating temperature, the fluid level should be
between the two “COLD” (lower) holes on the dipstick
with the fluid at 60-70°F / 16-21°C. Only use the COLD
region of the dipstick as a rough reference when setting
the fluid level after a transmission service or fluid
change. Re-check the fluid level, and adjust as required,
once the transmission reaches normal operating tempera-
ture.
CAUTION!
If the fluid temperature is below 50°F (10°C) it may
not register on the dipstick. Do not add fluid until
the temperature is elevated enough to produce an
accurate reading. Run the engine at idle, in PARK, to
warm the fluid.
8. Reinsert the dipstick. Check for leaks. Release the
parking brake.
NOTE:To prevent dirt and water from entering the
transmission after checking or replenishing fluid, make
sure that the dipstick cap is properly reseated. It is
normal for the dipstick cap to spring back slightly from
its fully seated position, as long as its seal remains
engaged in the dipstick tube.
Fluid And Filter Changes — Eight-Speed
Transmission
Under normal operating conditions, the fluid installed at
the factory will provide satisfactory lubrication for the
life of the vehicle.
Routine fluid and filter changes are not required. How-
ever, change the fluid and filter if the fluid becomes
contaminated (with water, etc.), or if the transmission is
disassembled for any reason.
7
MAINTAINING YOUR VEHICLE 789
Page 831 of 871

NOTE: 1500 Models Only
•Under no circumstances should oil change intervals
exceed 10,000 miles (16,000 km) or twelve months on
1500 trucks, whichever comes first.
2500 – 3500 Models
•Under no circumstances should oil change intervals
exceed 8,000 miles (13,000 km) or twelve months on
2500 – 3500 trucks, whichever comes first.
Severe Duty All Models
•Change Engine Oil at 4000 miles (6,500 km) if the vehicle
is operated in a dusty and off road environment. This
type of vehicle use is considered Severe Duty
Once A Month Or Before A Long Trip:
•Check engine oil level
•Check windshield washer fluid level
•Check tire pressure and look for unusual wear or
damage. Rotate tires at the first sign of irregular wear,
even if it occurs before the oil indicator system turns on.
•Check the fluid levels of the coolant reservoir, brake
master cylinder, power steering (2500/3500 Models
Only) and automatic transmission (six-speed only)
and fill as needed
•Check function of all interior and exterior lights
8
MAINTENANCE
SCHEDULES
MAINTENANCE SCHEDULES 829