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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.
7 MAINTAINING YOUR VEHICLE 423
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With disc brakes the fluid level can be expected to fall as
the brake linings wear. However, an unexpected drop in
fluid level may be caused by a leak and a system check
should be conducted.
Use only the manufacturer’s recommended brake fluid.
Refer to “Fluids, Lubricants, and Genuine Parts” in
“Maintaining Your Vehicle” for further information. WARNING!• Use only manufacturer’s recommended brake
fluid. Refer to “Fluids, Lubricants, and Genuine
Parts” in “Maintaining Your Vehicle” for further
information. Using the wrong type of brake fluid
can severely damage your brake system and/or
impair its performance. The proper type of brake
fluid for your vehicle is also identified on the
original factory installed hydraulic master cylin-
der reservoir.
(Continued)424 MAINTAINING YOUR VEHICLE
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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
7 MAINTAINING YOUR VEHICLE 425
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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
Page 429 of 502

Transfer Case
Drain And Refill
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.
Fluid Level Check
This fluid level can be checked by removing the filler
plug. The fluid level should be to the bottom edge of the
filler plug hole with the vehicle in a level position. Automatic Transmission
Selection Of Lubricant
It is important that the proper lubricant is used in the
transmission to assure optimum transmission perfor-
mance. Use only the manufacturer ’s recommended trans-
mission fluid. Refer to “Fluids, Lubricants, and Genuine
Parts” in “Maintaining Your Vehicle” for further informa-
tion. It is important that the transmission fluid be main-
tained at the prescribed level using the recommended
fluid.
CAUTION!• Do not use chemical flushes in your transmission
as the chemicals can damage your transmission
components. Such damage is not covered by the
New Vehicle Limited Warranty.
(Continued)
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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
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2. The vehicle must be on level ground.
3. Fully apply the parking brake and press the brake
pedal.
4. Place the shift lever momentarily into each gear posi-
tion ending with the lever in PARK.
5. Remove the dipstick, wipe it clean and reinsert it until
seated.
6. Remove the dipstick again and note the fluid level on
both sides. The fluid level should be between the “HOT”
(upper) reference holes on the dipstick at normal operat-
ing temperature. Verify that solid coating of oil is seen on
both sides of the dipstick. If the fluid is low, add as
required into the dipstick tube. Do not overfill. After
adding any quantity of oil through the oil fill tube, wait
a minimum of two minutes for the oil to fully drain into
the transmission before rechecking the fluid level. NOTE: If it is necessary to check the transmission below
the operating temperature, the fluid level should be
between the two “COLD” (lower) holes on the dipstick
with the fluid at approximately 70°F (21°C) (room tem-
perature). If the fluid level is correctly established at
room temperature, it should be between the “HOT”
(upper) reference holes when the transmission reaches
180°F (82°C). Remember it is best to check the level at the
normal operating temperature.
CAUTION!Be aware that 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.
7. Check for leaks. Release parking brake.
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To prevent dirt and water from entering the transmission
after checking or replenishing fluid, make certain 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.
Automatic Transmission Fluid And Filter Change
Refer to the “Maintenance Schedule” for the proper
maintenance intervals.
NOTE: If the transmission is disassembled for any
reason, the fluid and filter(s) should be changed.
It is important that proper lubricant is used in the
transmission. Refer to “Fluids, Lubricants, and Genuine
Parts” in “Maintaining Your Vehicle” for further
information. Appearance Care And Protection From Corrosion
Protection Of Body And Paint From Corrosion
Vehicle body care requirements vary according to geo-
graphic locations and usage. Chemicals that make roads
passable in snow and ice, and those that are sprayed on
trees and road surfaces during other seasons, are highly
corrosive to the metal in your vehicle. Outside parking,
which exposes your vehicle to airborne contaminants,
road surfaces on which the vehicle is operated, extreme
hot or cold weather and other extreme conditions will
have an adverse affect on paint, metal trim, and under-
body protection.
The following maintenance recommendations will enable
you to obtain maximum benefit from the corrosion
resistance built into your vehicle.
What Causes Corrosion?
Corrosion is the result of deterioration or removal of
paint and protective coatings from your vehicle.430 MAINTAINING YOUR VEHICLE