•Maintain proper steering gear and power steering pump lubricant
levels.
•Regularly inspect steering column joint bolts and steering linkage,
particularly for body-to-chassis clearance.
Note:Have any steering problems corrected at once by a qualified
service technician.
Failure to maintain the steering system in proper condition can
cause reduced steering ability resulting in property damage,
personal injury or death.
Tightening steering column joint bolts
As a good maintenance practice, it is recommended that steering column
joint bolts be checked for tightness every 60,000 miles (96,000 km) or
annually, whichever occurs first. DO NOT OVERTIGHTEN.
Power steering
Whenever the power steering’s hydraulic system has been drained and
refilled for any reason, air must be bled from the system before returning
the vehicle to service. Failure to properly bleed the hydraulic system can
result in degradation of power system performance.
Consult your dealer who is aware of the proper procedures for filling and
bleeding the system.
OPENING THE HOOD
The hood and fenders are held in position by a latch located on each
fender.
The parking brake must be fully set before opening the hood or
possible personal injury may occur.
To reduce the risk of the possibility of personal injury, never
stand beneath the hood when it is being raised or lowered.
If you must leave the engine running while checking under the
hood, do not allow any loose clothing, jewelry, hair or other
items to get near moving engine components or possible personal
injury may occur.
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Running out of fuel
Avoid running out of fuel as this will allow air to enter the fuel system,
which will make restarting the vehicle difficult.
If you have run out of fuel:
•If your vehicle is equipped with dual fuel tanks,add at least 4–5
gallons (15–19 liters) of fuel to each tank before attempting to restart
the engine.
•The fuel system must be primed before attempting to restart the
engine. Refer to the engine operator’s manual for instructions on
priming the engine.
•Use caution not to overheat and damage the starterby cranking
the engine for an excessive period of time. You may need to crank the
engine for a longer time than normal. If the engine fails to start in 30
seconds, turn the ignition to the OFF position and wait for two
minutes before cranking the engine again.
•Any remaining trapped air will self-purge from the fuel system once
the engine starts running.
•The engine may run rough and produce white smoke while air is in
the fuel system. This is normal and should stop after a short period of
time.
FUEL CONSUMPTION IMPROVEMENT MEASURES
There are two important factors you can control to improve fuel
economy: the mechanical condition of your vehicle and how you drive it.
A properly maintained vehicle will deliver better performance than a
neglected vehicle. Always follow your maintenance schedule to keep your
vehicle in top operating condition.
Also, your driving habits have a significant influence on use of fuel. By
following these suggestions, you can stretch your fuel use:
•Avoid changes in speed as much as possible.
•Anticipate changing traffic conditions. Sudden stops and fast
acceleration waste fuel.
•Avoid extensive idling.
•Do not drive with your foot resting on the brake pedal.
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Calculating fuel economy
1. Fill the fuel tank(s) completely and record the initial odometer
reading (in miles or kilometers).
2. Each time you fill the tank(s), record the amount of fuel added (in
gallons or liters).
3. After at least three to five tank fill-ups, fill the fuel tank(s) and record
the current odometer reading.
4. Subtract your initial odometer reading from the current odometer
reading.
5. Follow one of the simple calculations in order to determine fuel
economy:
•Divide total miles traveled by total gallons used.
•Multiply liters used by 100, then divide by total kilometers traveled.
Keep a record for at least one month and record the type of driving (city
or highway). This will provide an accurate estimate of the vehicle’s fuel
economy under current driving conditions. Additionally, keeping records
during summer and winter will show how temperature impacts fuel
economy. In general, lower temperatures give lower fuel economy.
Driving style - good driving and fuel economy habits
Give consideration to the lists that follow and you may be able to change
a number of variables and improve your fuel economy.
Habits
•Smooth, moderate operation can yield up to 10% savings in fuel.
•Steady speeds without stopping will usually give the best fuel
economy.
•Anticipate stopping; slowing down may eliminate the need to stop.
•Sudden or hard accelerations may reduce fuel economy.
•Slow down gradually.
•Driving at reasonable speeds (traveling at 55 mph [88 km/h] uses 15%
less fuel than traveling at 65 mph [105 km/h]).
•Using the air conditioner or defroster may reduce fuel economy.
•Resting your foot on the brake pedal while driving may reduce fuel
economy.
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Conditions
•Carrying unnecessary weight may reduce fuel economy.
•Fuel economy may decrease with lower temperatures during the first
8–10 miles (12–16 km) of driving.
•Flat terrain driving improves fuel economy over hilly roads.
•Transmissions give their best fuel economy when operated in the top
cruise gear and with steady pressure on the accelerator.
•Close windows for highway driving.
DIESEL PARTICULATE FILTER (DPF)
Your vehicle is equipped with a diesel particulate filter (DPF), as part of
the after-treatment exhaust system, to trap soot and other large particles
produced by the engine combustion process. The soot that accumulates
in the filter must be periodically reduced to ash to prevent excessive
exhaust restriction. The soot reduction process, also known as “filter
regeneration,” is generally performed automatically by your engine and
after-treatment system.
The normal operating temperature of the exhaust system is very
high. Never work around, or attempt to repair, any part of the
exhaust system until it has cooled. Use special care when working
around the diesel particulate filter. The DPF heats up to a high
temperature after only a short period of engine operation, and can
remain hot even after the engine is turned off. Failure to follow these
instructions may result in personal injury.
Diesel particulate filter regeneration (Caterpillar engine only)
DPF regeneration requires no operator interaction and may occur at any
time. A small increase in engine sound-level during filter regeneration is
normal and should be no reason for concern.
A separate fuel injector/nozzle, which requires periodic cleaning, is used
in the regeneration process. Refer to Caterpillar’sOperation and
Maintenance Manualfor details regarding cleaning requirements.
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When these steps are performed successfully in the order outlined above,
the DPF lamp will begin flashing at a rate of once every 10 seconds. The
engine speed may also increase slightly. To allow parked regeneration to
continue uninterrupted:
1. The vehicle must remain parked
2. The transmission must remain in P (Park) or N (Neutral) (as
previously described in Step 2).
3. The accelerator pedal, service brake pedal, and clutch pedal (if
equipped) must not be depressed
4. The parking brake must remain set
On average (depending on filter level and other factors), the process will
take 20–30 minutes to complete. The DPF lamp will turn off when the
process is complete. Repeat Steps 1–5, if parked regeneration is
interrupted.
To discontinue parked regeneration (Cummins engine only)
Depress any of the floor pedals to discontinue parked regeneration.
Diesel particulate filter maintenance and service
The DPF is designed to retain a relatively large amount of residual ash
and provide many miles and hours of maintenance-free operation. At
some point, generally beyond 150,000 miles (240,000 km) or 5,000 hours
of operation (whichever comes first), the DPF will require professional
cleaning to remove the accumulated ash
The exact number of miles or hours of operation will vary greatly
depending upon vehicle/engine loading and operating conditions, ash
content of the engine oil, and quality of the diesel fuel used in your
truck. Adhering to your engine manufacturer’s recommended oil and fuel
specifications will maximize the miles and hours of operation before a
DPF professional cleaning is required. Refer to your engine
manufacturer’s owner’s manual for more details regarding recommended
maintenance and service of your DPF.
Exhaust outlet assembly
The normal operating temperature of the exhaust system is very
high. Never work around or attempt to repair any part of the
exhaust system until it has cooled. Failure to follow these instructions
may result in personal injury.
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such as the fuel sender, cranking motor, alternator and feed-through
studs should be cleaned and re-coated with a lubricant sealing grease
such as Motorcraft Silicone Brake Caliper Grease and Dielectic
Compound XG-3, or equivalent. This should include the ground cable
connector for batteries, engine and cab as well as the jump starting stud.
Accessory feed connections
Vehicle electrical systems are complex and often include electronic
components such as engine and transmission controls, instrument panels,
ABS, etc. While most systems operate on battery voltage (12 volts),
some systems can be as high as 90 volts or as low as five volts. Refer to
the Electrical Circuit Diagram Manuals, available from your vehicle’s
manufacturer, to ensure that any additional body lights and accessories
are connected to circuits that are both appropriate and not overloaded.
No modification should be made to any vehicle control system without
first contacting your dealer.
SUSPENSION INSPECTION
Note:Do not adjust air suspension height to any setting other than the
specified setting. Altering the height setting will change the driveline
angle and may result in unwarrantable component damage, such as
transmission component damage.
Verify drive axle air suspension height and height control valve
performance at engine lube oil change intervals.
Periodically:
•Check condition of spring leaves for evidence of fatigue, bending or
breakage.
•Check condition of suspension mounting brackets and bushings.
•Check that torque rod mounting fasteners are tight.
•Check to be sure the suspension alignment is maintained at all times.
•Check U-bolts after the chassis has been operating under load for
1,000 miles (1,600 km) or six months, whichever comes first, the
U-Bolt nuts must be re-torqued. The U-Bolt nuts thereafter must be
re-torqued every 36,000 miles (58,000 km). The U-Bolt and nut
threads and seats should be cleaned and lubricated to ensure a “like
new” condition when re-torquing.
Note:See theU-Bolt Nut Torquechart later in this section.
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Air suspension U-bolt checks and re-torquing procedures
1. Inspect the threads of the U-bolt and nut for rust and debris. Clean
the threads if contaminated.
2. Using a torque wrench, determine if any nuts can be turned with a
force below the specified torque.
3. Using the lowest discovered torqued nut as a starting point, retighten
the nuts using the sequence listed underAir suspension U-bolt and
U-bolt nut installation.
Air suspension U-bolt and U-bolt nut installation
1. Inspect the threads of the U-bolt and nut for rust and debris. Clean
the threads if contaminated.
2. Install the U-bolts and nuts and torque the nuts to 15 ft. lb. (20 N•m),
using a diagonal pattern.
3. Re-torque the nuts to 100 ft. lb. (136 N•m), using a diagonal pattern.
4. Re-torque the nuts to 200 ft. lb. (271 N•m), using a diagonal pattern.
5. Re-torque the nuts to 400 ft. lb. (542 N•m), using a diagonal pattern.
(For vehicles equipped with 14ACC, 14 ADN and 14ADP axles, do not
use Step 6.)
6. Re-torque the nuts to 425 ft. lb (576 N•m), using a diagonal pattern.
(For vehicles equipped with 14ACC, 14 ADN and 14ADP axles.)
7. Use the same diagonal pattern with each U-bolt nut re-torque.
Spring U-bolt checks
Check U-bolt nuts and re-torque every 36,000 miles (58,000 km) after
initial 1,000 miles (1,600 km) re-torque. The U-bolt and nut threads and
seats should be cleaned and lubricated to ensure peak condition when
re-torqued.
DRIVESHAFT
At the regular lubrication interval, check the universal joints for any
evidence of wear or looseness. Should driveshaft vibrations occur, stop
the vehicle immediately to avoid possible hazardous consequences or
damage to other components.
REAR AXLE LUBRICANT
Refer to theScheduled Maintenance Guidechapter for rear axle
lubricant level checks and lubricant change intervals.
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When installing wheel balance weights, they must be mounted on the
dome-side of the wheel only. Failure to do so may result in loss of wheel
weight and/or damage to brakes or wheels.
Important:Remember to replace the wheel air valves when the road
tires are replaced at the end of their useful life.
Oil lubricated front wheel bearings
During normal vehicle duty cycle, the lube and air inside the hub/wheel
cavity expands and if not vented, causes pressure build-up that could
cause accelerated seal wear.
There are two venting methods:
•a slit or small hole in the rubber check vent or
•the window
You can use either of these methods to prevent pressure build-up.
Normal maintenance
Over a period of time, if not routinely cleaned, a slight film of oil can
collect dirt around the rubber fill plug and face, which could appear to
be a leak. Routine cleaning ensures that the lube level can be easily
observed through the clear window as intended. In situations where the
window is clean on the outside but discolored on the inside, the lube
level may be checked by inserting a finger through the rubber check
vent hole.
The specified lube level for a clear window type hubcaps is from the
minimum line to + 5/16 inch above the minimum line.
If the lube level should suddenly drop dramatically below the minimum
level, see theWorkshop Manualfor diagnostic procedure.
Installation, tightening and alignment
When installing wheels, be certain that the threads on studs and nuts are
clean to permit correct torque. The mounting surfaces of rims, wheels,
spacer rings and clamps must be free of dirt, rust, lubricants or damage.
Use a wire brush to clean the mounting contact surfaces. Do not use
lubricant on threads.
After the rim or wheel has been properly tightened, it should be checked
for alignment. Rotate the wheel with a piece of chalk attached to a
steady, firm surface, and placed to just barely clear the outside surface of
the tire bead seat. This procedure will point out the high spot. A high
spot does not necessarily mean that the lug nuts have been unevenly
tightened. This condition or misalignment could be caused by a bent
wheel.
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