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•Check the coolant and oil levels frequently.
•Vary throttle position at highway speeds when carry-
ing or towing significant weight.
Because of the construction of the Cummins Diesel
engine, engine run-in is enhanced by loaded operating
conditions which allow the engine parts to achieve final
finish and fit during the first 6,000 miles (10 000 km).
CAUTION!
•During the first 500 miles (805 km) your new
vehicle is driven, do not tow a trailer. Doing so
may damage your vehicle.
•Limit your speed to 50 mph (80 km/h) during the
first 500 miles (805 km) of towing.
SAFETY TIPS
Transporting Passengers
This vehicle is designed to carry passengers in the cab
only. For safety reasons, NEVER TRANSPORT PASSEN-
GERS IN THE CARGO AREA.
WARNING!
It is extremely dangerous to ride in a cargo area,
inside or outside of a vehicle. In a collision, people
riding in these areas are more likely to be seriously
injured or killed.
Do not allow people to ride in any area of your
vehicle that is not equipped with seats and seat belts.
Be sure everyone in your vehicle is in a seat and
using a seat belt properly.
THINGS TO KNOW BEFORE STARTING YOUR VEHICLE 75
2
Page 414 of 552

MAINTENANCE PROCEDURES
The pages that follow contain therequiredmaintenance
services determined by the engineers who designed your
vehicle.
Besides the maintenance items for which there are fixed
maintenance intervals, there are other items that should
operate satisfactorily without periodic maintenance.
However, if a malfunction of these items does occur, it
could adversely affect the engine or vehicle performance.
These items should be inspected if a malfunction is
observed or suspected.
Engine Oil
Checking Oil Level
To assure proper lubrication of your vehicle’s engine, the
engine oil must be maintained at the correct level. Check
the oil level at regular intervals. The best time to check
the oil level is before starting the engine after it has been
parked overnight. When checking oil after operating the
engine, first ensure the engine is at full operating tem-
perature, then wait at least 30 minutes after engine
shutdown to check the oil.
Checking the vehicle while it’s on level ground will also
improve the accuracy of the oil level readings. Add oil
only when the level on the dipstick is below the “ADD”
mark. The total capacity from the low mark to the high
mark is 2 quarts (1.9 liters).
414 MAINTAINING YOUR VEHICLE
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CAUTION!
Overfilling or underfilling the crankcase will cause
oil aeration or loss of oil pressure. This could damage
your engine.Never operate the engine with oil level below the “ADD”
mark or above the upper “SAFE” mark.Change Engine Oil (5.9L Diesel Engine)
Road conditions as well as your kind of driving affect the
interval at which your oil should be changed. Check the
following to determine if any apply to you:
•Frequent short trips where the engine does not achieve
full operating temperature (operating temperature de-
fined as 190° F (66° C ) coolant temperature).
•Extensive engine idling (over 10 minutes per hour of
operation) at ambient temperatures less than 32° F (0°
C).
•Driving in dusty conditions.
•Frequent trailer towing.
•Taxi, police, or delivery service (commercial service).
•Off-road or desert operation.
MAINTAINING YOUR VEHICLE 415
7
Page 421 of 552

Install the filter as specified by the filter manufacturer.
Turn the filter 3/4 to one full turn after making contact
with the gasket.
Check the condition of the threads and sealing surface on
the oil pan and drain plug.
Install the drain plug and sealing washer and tighten to
37 ft-lbs. (50 N·m).
Use only high-quality multi-grade lubricating oil in your
Cummins Diesel Engine. Choose the correct oil for your
operating conditions as outlined in the Selection of
Engine Oil.
Cummins Turbo Diesel
Fill the engine with the correct grade of new oil. The
engine capacity is 11 quarts (10.4 liters) in the crankcase
and 1 quart (.95 liter) in the lubricating oil filter.Start the engine and operate it at idle for several minutes.
Check for leaks at the lubricating oil filter and oil pan
drain plug.
Run the engine until it has reached operating tempera-
ture, stop the engine. Wait approximately 15 minutes to
let the oil in the upper parts of the engine drain back to
the pan. Check the oil level again.
Add oil as necessary to bring the level to the “SAFE”
mark on the dipstick.
Disposing Of Used Engine Oil And Filter
Care should be taken in disposing of the used engine
fluids from your vehicle. Used fluids, indiscriminately
discarded, can present a problem to the environment.
Contact your local dealer, service station, or governmen-
tal agency for advice on recycling programs and where
used fluids and filters can be safely discarded in your
area.
MAINTAINING YOUR VEHICLE 421
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Page 442 of 552

The external lock cylinders should be lubricated twice a
year, preferably in the fall and spring. Apply a small
amount of a high quality lubricant such as MoparLock
Cylinder Lubricant directly into the lock cylinder.
Windshield Wiper Blades
The rubber edges of the wiper blades and the windshield
should be cleaned periodically with a sponge or soft cloth
and a mild nonabrasive cleaner. This will remove accu-
mulations of salt or road film.
Operation of the wipers on dry glass for long periods
may cause deterioration of the wiper blades. Always use
washer fluid when using the wipers to remove salt or dirt
from a dry windshield.
Avoid using the wiper blades to remove frost or ice from
the windshield. Keep the blade rubber out of contact with
petroleum products such as engine oil, gasoline, etc.
Windshield Washers
The fluid reservoir is located under the hood and should
be checked for fluid level at regular intervals. Fill the
reservoir with windshield washer solvent only (not ra-
diator antifreeze).
When refilling the washer fluid reservoir, take some
washer fluid and apply it to a cloth or towel and wipe
clean the wiper blades, this will help blade performance.
To prevent freeze-up of your windshield washer system
in cold weather, select a solution or mixture that meets or
exceeds the temperature range of your climate. This
rating information can be found on most washer fluid
containers.
442 MAINTAINING YOUR VEHICLE
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accumulation of bugs, leaves, etc. If dirty, clean by gently
spraying water from a garden hose vertically down the
face of the condenser.
Check the coolant recovery bottle tubing for brittle rub-
ber, cracking, tears, cuts and tightness of the connection
at the bottle and radiator. Inspect the entire system for
leaks.
Extremely cold ambient temperature may require the
addition of a “winter front” for effective operation of the
cab heating/cooling system. Make certain that a percent-
age of the radiator is exposed for adequate air flow
through the charge air cooler and automatic transmission
oil cooler. The percentage of opening must be increased
with the increasing ambient air temperature and/or
engine load. If the cooling fan can be heard cycling
frequently, increase the size of the opening in the winter
front.Coolant bottle level check
The coolant reserve system provides a quick visual
method of determining that the coolant level is adequate.
With the engine idling, and warmed to the normal
operating temperature, the level of the coolant on the
coolant bottle should be between the fluid level marks.
Check the coolant level whenever the hood is raised.
The radiator normally remains completely full, so there is
no longer a need to remove the coolant pressure cap
except for checking coolant freeze point or replacement
with new antifreeze coolant.
WARNING!
Never add coolant to the radiator when the engine is
overheated. Do not loosen or remove pressure cap to
cool overheated engine! The coolant is under pres-
sure and severe scalding could result.
MAINTAINING YOUR VEHICLE 445
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Page 452 of 552
Brake Master Cylinder
The fluid level of the master cylinder should be checked
when performing under the hood service, or immedi-
ately 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“FULL” dot and an “ADD” dot. The fluid level must be
kept within these two dots. Do not add fluid above the
full mark because leakage may occur at the cap.
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.
Refer to Fluids, Lubricants and Genuine Parts for the
correct Fluid type.
WARNING!
Use of a brake fluid that may have a lower initial
boiling point, or unidentified as to specification, may
result in sudden brake failure during hard prolonged
braking. You could have an accident.
452 MAINTAINING YOUR VEHICLE
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Rear Axle And 4x4 Front Driving Axle Fluid Level
For Model 9.25 Front Axles and 10.5”/11.5” Rear Axles
refer to Fluids, Lubricants and Genuine Parts for the
correct lubricant type. For normal service, periodic fluid
level checks are not required. When the vehicle is ser-
viced for other reasons, the exterior surfaces of the axle
assembly should be inspected.
When checking the fluid level, the vehicle should be in a
level position. The fluid level should be 1/4” ± 1/4” (6.4
mm ± 6.4 mm) below the fill hole on the 9.25” Front Axle.
The fluid level should be 3/4” ± 1/4” (19 mm ± 6.4 mm)
below the fill hole on all 10.5” and 1/4” ± 1/4” (6.4 mm
± 6.4 mm) on 11.5” Rear Axles.
Drain And Refill
Vehicles operated in normal service do not have regularly
scheduled oil changes. If fluid has become contaminatedwith water or subjected to severe service, follow the
recommended change intervals in Maintenance Schedule
“B” in Section 8 of this manual.
Lubricant Selection
Refer to Fluids, Lubricants and Genuine Parts for the
correct lubricant type.
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 Differentialsin vehicles equipped with
10.5”/11.5” AxlesDO NOT REQUIREany limited slip
oil additive (friction modifiers).
454 MAINTAINING YOUR VEHICLE