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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.
Selection Of Coolant
Refer to “Fluids, Lubricants, And Genuine Parts” in
“Maintaining Your Vehicle” for further information.
584 MAINTAINING YOUR VEHICLE
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•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.90032) 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.
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.
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MAINTAINING YOUR VEHICLE 589
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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 evident
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.
4500/5500 Rear Axle Plugs
1 — 4500/5500 Rear Axle Fluid Fill Plug
2 — 4500/5500 Rear Axle Fluid Drain Plug 592 MAINTAINING YOUR VEHICLE
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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 — If Equipped
Selection Of Lubricant
It is important to use the proper transmission fluid to
ensure optimum transmission performance and life. Useonly the manufacturer ’s specified transmission fluid.
Refer to “Fluids, Lubricants, And Genuine Parts” in this
section for fluid specifications. It is important to maintain
the transmission fluid at the correct level using the
recommended fluid. No chemical flushes should be used
in any transmission; only the approved lubricant should
be used.
CAUTION!
Using a transmission fluid other than the manufac-
turer ’s recommended fluid may cause deterioration
in transmission shift quality and/or torque converter
shudder, and will require more frequent fluid and
filter changes. Refer to “Fluids, Lubricants, And
Genuine Parts” in this section for fluid specifica-
tions.
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Fluid And Filter Changes — Six Speed
Transmission
Refer to the “Maintenance Schedule” for the proper
maintenance intervals.
In addition, change the fluid and filter(s) if the fluid
becomes contaminated (with water, etc.), or if the trans-
mission is disassembled for any reason.
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 chemicals 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 contami-
nants, road surfaces on which the vehicle is operated,extreme hot or cold weather and other extreme condi-
tions will have an adverse effect on paint, metal trim, and
underbody 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.
The most common causes are:
•
Road salt, dirt and moisture accumulation.
• Stone and gravel impact.
• Insects, tree sap and tar.
• Salt in the air near seacoast localities.
• Atmospheric fallout/industrial pollutants.
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MAINTAINING YOUR VEHICLE 597
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MAINTENANCE SCHEDULES
CONTENTS
MAINTENANCE SCHEDULE .............626▫Maintenance Chart ....................628
8
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MAINTENANCE SCHEDULE
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.
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 “Oil Change Required” message is
displayed. Severe Operating Conditions can cause the
change oil message to illuminate as early as 3,500 miles
(5,600 km) since last reset. Have your vehicle serviced as
soon as possible, within the next 500 miles (805 km).
Your authorized dealer will reset the oil change indicator
message after completing the scheduled oil change. If a
scheduled oil change is performed by someone otherthan your authorized dealer, the message can be reset by
referring to the steps described under “Electronic Vehicle
Information Center (EVIC)/Driver Information Display
(DID)” in “Understanding Your Instrument Panel” for
further information.
Gasoline Engines:
Under no circumstances should oil change intervals
exceed 8,000 miles (13,000 km), twelve months or 350
hours of engine run time, whichever comes first. The 350
hours of engine run or idle time is generally only a
concern for fleet customers.
Severe Duty:
Change Engine Oil at 4,000 miles (6,500 km) if the vehicle
is operated in a dusty and off road environment or is
operated predominately at idle or very low engine
RPM’s. This type of vehicle use is considered Severe Duty
626 MAINTENANCE SCHEDULES
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Once A Month Or Before A Long Trip:
•Check engine oil level
• Check windshield washer fluid level
• Check the tire inflation pressures and look for unusual
wear or damage
• Check the fluid levels of the coolant reservoir, brake
master cylinder, power steering and automatic trans-
mission and fill as needed.
• Check function of all interior and exterior lights
Required Maintenance
Refer to the Maintenance Schedules on the following
pages for required maintenance.
At Every Oil Change Interval As Indicated By Oil Change Indicator System:
•Change oil and filter.
At Every Oil Change Interval As Indicated By Oil
Change Indicator System:
•Rotate the tires. Rotate at the first sign of irregu-
lar wear, even if it occurs before the oil indicator
system turns on.
• Inspect battery and clean and tighten terminals as
required.
• Inspect automatic transmission fluid if equipped
with dipstick.
• Inspect brake pads, shoes, rotors, drums, hoses
and park brake.
• Inspect engine cooling system protection and
hoses.
• Inspect exhaust system.
• Inspect engine air cleaner if using in dusty or
off-road conditions.
• Lube the front drive shaft fitting. 8
MAINTENANCE SCHEDULES 627