Page 423 of 502
2. Lift and remove the plastic dipstick from the reservoir
neck. 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 en-
gine coolant (antifreeze). Advise your service attendant
7 MAINTAINING YOUR VEHICLE 421
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• Keep the front of the radiator clean. If your vehicle is
equipped with air conditioning, keep the front of the
condenser clean, also.
• 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
emissions.
Brake System
In order to assure brake system performance, all brake
system components should be inspected periodically.
Refer to the “Maintenance Schedule” for the proper
maintenance intervals. WARNING!Riding the brakes can lead to brake failure and
possibly a collision. Driving with your foot resting or
riding on the brake pedal can result in abnormally
high brake temperatures, excessive lining wear, and
possible brake damage. You would not have your full
braking capacity in an emergency.
Brake Fluid Level Check
The fluid level of the master cylinder should be checked
when performing under the hood service or immediately
if the brake system warning lamp indicates system
failure.
The brake master cylinder has a translucent plastic
reservoir. On the outboard side of the reservoir, there is a
“MAX” dot and an “MIN” dot. The fluid level must be
kept within these two dots. Do not add fluid above the
MAX mark because leakage may occur at the cap.
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WARNING! (Continued)• To avoid contamination from foreign matter or
moisture, use only new brake fluid or fluid that
has been in a tightly closed container. Keep the
master cylinder reservoir cap secured at all times.
Brake fluid in a open container absorbs moisture
from the air resulting in a lower boiling point.
This may cause it to boil unexpectedly during hard
or prolonged braking, resulting in sudden brake
failure. This could result in a collision.
• Overfilling the brake fluid reservoir can result in
spilling brake fluid on hot engine parts, causing
the brake fluid to catch fire. Brake fluid can also
damage painted and vinyl surfaces, care should be
taken to avoid its contact with these surfaces.
(Continued) WARNING! (Continued)• Do not allow petroleum based fluid to contami-
nate the brake fluid. Brake seal components could
be damaged, causing partial or complete brake
failure. This could result in a collision.
Rear Axle And 4x4 Front Driving Axle Fluid Level
For models with 9.25 in Front Axles and 11.5 in Rear
Axles, refer to “Fluids, Lubricants, and Genuine Parts” in
“Maintaining Your Vehicle” for further information. For
normal service, periodic fluid level checks are not re-
quired. When the vehicle is serviced for other reasons,
the exterior surfaces of the axle assembly should be
inspected.
When checking the fluid level (4500/5500 only), the
vehicle should be in a level position. The fluid level
should be 1/4 in ± 1/4 in (6.4 mm ± 6.4 mm) below the
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fill hole on the front axle. The fluid level should be level
with the bottom of the fill hole on the rear axle.
Drain And Refill
On 4500/5500 vehicles, remove the lower bolt to drain
the axle fluid. Refer to the “Maintenance Schedule” for the proper
maintenance intervals.
Lubricant Selection
Refer to “Fluids, Lubricants, and Genuine Parts” in
“Maintaining Your Vehicle” for further information.
NOTE: The presence of water in the gear lubricant will
result in corrosion and possible failure of differential
components. Operation of the vehicle in water, as may be
encountered in some off-highway types of service, will
require draining and refilling the axle to avoid damage.
Limited-Slip Differentials DO NOT REQUIRE any
limited slip oil additive (friction modifiers).
NOTE: Slight noise and mild shuddering may be evi-
dent while turning a vehicle with limited slip differential
on concrete or dry pavement. These conditions should be
considered normal operation of the limited slip
differential.1 — 4500/5500 Rear Axle Fluid Fill Plug
2 — 4500/5500 Rear Axle Fluid Drain Plug426 MAINTAINING YOUR VEHICLE
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CAUTION! (Continued)• Using a transmission fluid other than the manu-
facturer’s recommended fluid may cause deterio-
ration in transmission shift quality and/or torque
converter shudder. Using a transmission fluid
other than the manufacturer’s recommended fluid
will require more frequent fluid and filter
changes. Refer to “Fluids, Lubricants, and Genu-
ine Parts” in “Maintaining Your Vehicle” for fur-
ther information.
Special Additives
Automatic Transmission Fluid (ATF) is an engineered
product and its performance may be impaired by supple-
mental additives. Therefore, do not add any fluid addi-
tives to the transmission. The only exception to this
policy is the use of special dyes to aid in detecting fluid
leaks. In addition, avoid using transmission sealers as
they may adversely affect seals. Fluid Level Check
The fluid level should be checked when the engine is
fully warmed up and the fluid in the transmission is at
normal operating temperature. Operation of the trans-
mission with an improper fluid level will greatly reduce
the life of the transmission and of the fluid. Check the
fluid level whenever the vehicle is serviced.
Fluid Level Check – 5.7L Engine
Check the fluid level while the transmission is at normal
operating temperature 82°C (180°F). This occurs after at
least 15 miles (25 km) of driving. At normal operating
temperature the fluid cannot be held comfortably be-
tween the fingertips.
To check the automatic transmission fluid level properly,
the following procedure must be used:
1. Operate the engine at idle speed and normal operating
temperature.428 MAINTAINING YOUR VEHICLE
Page 443 of 502

CAUTION! (Continued)• When replacing a blown fuse, it is important to
use only a fuse having the correct amperage rating.
The use of a fuse with a rating other than indicated
may result in a dangerous electrical system over-
load. If a properly rated fuse continues to blow, it
indicates a problem in the circuit that must be
corrected.
VEHICLE STORAGE
If you are storing your vehicle for more than 21 days, we
recommend that you take the following steps to mini-
mize the drain on your vehicle’s battery:
• Disconnect the Ignition-Off Draw (IOD) fuse located in
the Integrated Power Module, located in the engine
compartment. The IOD cavity includes a snap-in re-
tainer that allows the fuse to be disconnected without
removing it from the fuse block. • As an alternative to the above steps you may discon-
nect the negative cables from both batteries.
• Any time you store your vehicle or keep it out of
service (i.e., vacation) for two weeks or more, run the
air conditioning system at idle for about five minutes
in the fresh air and high blower setting. This will
ensure adequate system lubrication to minimize the
possibility of compressor damage when the system is
started again.
NOTE:
• When reinstalling the IOD fuse push firmly until fully
seated; the gauges in the instrument cluster will do a
full sweep when the ignition switch is turned to the
RUN position. This is a normal condition.
• When the vehicle is shipped from the factory, the IOD
fuse is in the up or extracted position. If the radio,
interior lamps, keyless entry or other features do not
work with the key OFF, check the position of the fuse
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MAINTENANCE SCHEDULE
5.7L Gas Engine
The Scheduled Maintenance services listed in this
manual must be done at the times or mileages specified
to protect your vehicle warranty and ensure the best
vehicle performance and reliability. More frequent main-
tenance may be needed for vehicles in severe operating
conditions, such as dusty areas and very short trip
driving. Inspection and service should also be done
anytime a malfunction is suspected.
Your vehicle is equipped with an automatic oil change
indicator system. The oil change indicator system will
remind you that it is time to take your vehicle in for
scheduled maintenance.
On Electronic Vehicle Information Center (EVIC)
equipped vehicles, “Oil Change Required” will be dis-
played in the EVIC and a single chime will sound,
indicating that an oil change is necessary. On Non-EVIC equipped vehicles, “Change Oil” will flash
in the instrument cluster odometer and a single chime
will sound, indicating that an oil change is necessary.
Based on engine operation conditions, the oil change
indicator message will illuminate. This means that ser-
vice is required for your vehicle. Operating conditions
such as frequent short-trips, trailer tow, extremely hot or
cold ambient temperatures, and E85 fuel usage will
influence when the “Change Oil” message is displayed.
Depending on operating conditions, the message may
appear as early as 3,500 miles (5 630 km) since last reset.
Have your vehicle serviced as soon as possible, within
the next 500 miles (805 km).
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8,000 Miles (13,000 km) or
6 Months Maintenance Service
Schedule ❏ Change the engine oil and engine oil
filter.
❏ Rotate the tires, rotate at the first sign of
irregular wear, even if it occurs before
8,000 miles (13 000 km).
❏ Lube the front drive shaft fitting (4x4
only).
Odometer Reading Date
Repair Order # Dealer Code
Signature, Authorized Service Center 16,000 Miles (26,000 km) or 12 Months Maintenance Service
Schedule ❏ Change the engine oil and engine oil filter.
❏ Rotate the tires, rotate at the first sign of irregular wear, even if it occurs before
16,000 miles (26 000 km).
❏ If using your vehicle for any of the following: Dusty or off-road conditions. Inspect the
engine air cleaner filter; replace if necessary.
❏ Lube the front drive shaft fitting (4x4 only).
❏ Inspect the brake linings, replace if necessary.
❏ Inspect exhaust system. Perform the first inspection at 16,000 miles (26 000 km) or
12 months.
❏ Inspect the front suspension, tie rod ends and boot seals for cracks or leaks and all parts for
damage, wear, improper looseness or end play; replace if necessary.
Odometer Reading Date
Repair Order # Dealer Code
Signature, Authorized Service Center
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