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vehicle at least once a year. Remember that regular maintenance and
replacement of worn components will usually prevent serious problems
from developing later.
Making modifications to various parts, components and systems
of the vehicle, such as brake and steering systems can adversely
affect the quality, reliability and operation of your vehicle and could
result in property damage, personal injury or death. Such modifications
must be avoided.
The lubrication intervals present a good opportunity to inspect the
vehicle. It is suggested that the various points listed herein be checked
at the lubrication or other recommended intervals.
Failure to properly perform maintenance and servicing
procedures could result in vehicle damage, personal injury or
death.
If the owner/operator of the vehicle is a skilled technician and intends on
performing the vehicle maintenance and service, he is strongly urged to
purchase a service manual.
Take care when performing any maintenance, system check or
service on your vehicle. Some of the materials may also be
hazardous if used, serviced or handled improperly and could result in
property damage, personal injury or death.
Air conditioning system checks
Have your air conditioning system checked each spring. The refrigerant
charge, cleanliness of the condenser-evaporator cores and belt condition
are essential to air conditioning performance.
When the air conditioning system is being used daily, remove the fresh
air filter (if equipped) once each season and check for dirt, lint, etc.
Replace the filter if necessary. Vehicles operating in unusually dusty
conditions may require inspecting and replacing the fresh air filter more
often.
Front axle - general service information
Maintaining the front axle alignment to specifications is very important
and should only be performed by a qualified technician. Toe-in
adjustment is particularly important with radial tires.
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Check to make sure that the axle mounting U-bolt nuts, attaching or
mounting bolts and nuts are securely tightened. Regularly check front
axle for damage, binding, worn parts and adequate lubrication.
At regular intervals, or during other scheduled maintenance, (tire
rotation/service, wheel bearing service, alignment, etc.) the kingpins
should be checked for excessive wear. Refer to the service manual for
proper procedures.
Toe-in setting - general inspection
Inspecting steer axle tires in the first 3,000–10,000 service miles
(4,800–16,000 service km) will generally show if tires are wearing
normally.
Rapid outside shoulder wear on both tires indicates too much toe-in.
Rapid inside shoulder wear on both tires indicates too much toe-out. In
P&D-type service, left-to-right steer tire tread life differentials up to 40%
can be observed depending on routes and other variables.
Follow the tire manufacturer’s recommended cold inflation pressure for
the tire size, load range (ply rating) and steer axle loading typical for
their operation (each steer axle tire will equal
1 2steer axle loading).
Special applications may warrant a setting based on past experience with
the type of tire operating loads and conditions. Radial tires are more
sensitive to toe-in setting than bias ply tires. While not insensitive to
vehicle alignment, fine tuning school bus alignment to line-haul truck
standards will not drastically improve tire tread life.
It is essential that correct toe-in and tire pressure be maintained for
optimum tire wear.
Rear axle - general inspection
Check to make sure that the axle mounting U-bolts, attaching or
mounting bolts and nuts are securely tightened. Refer toU-bolt nut
torquein this chapter. Regularly check the rear axle for damaged,
binding or worn parts.
NoSpin Detroit Locker positive locking differential
Vehicles equipped with this type differential have the operator’s manual
supplied with the vehicle. Refer to this manual for maintenance checks.
Brake system - general inspection
Your vehicle is equipped with non-asbestos brake linings. However,
exposure to excessive amounts of brake material (whether asbestos or
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non-asbestos, fiberglass, mineral wool, aramid or carbon) may be a
potentially serious health hazard.
Avoid breathing brake lining fiber dust as it may be extremely
hazardous to your health. Always use a respirator during brake
maintenance.
Note:Persons handling brake linings should follow all precautions listed
below:
1. Always wear a respirator approved by the National Institute of
Occupational Studies of Health (NIOSH) or Mine Safety and Appliance
(MSA) during all brake service procedures. Wear the respirator from
removal of the wheels through assembly.
2.Neveruse compressed air or dry brushing to clean brake parts or
assemblies.
3. Clean brake parts and assemblies in open air. During assembly,
carefully place all parts on the floor to avoid getting dust in the air. Use
an industrial vacuum cleaner with a HEPA filter system to clean dust
from the brake drums, backing plates and other brake parts. After using
the vacuum, remove any remaining dust with a rag soaked in water and
wrung until nearly dry.
4.Neveruse compressed air or dry sweeping to clean the work area.
Use an industrial vacuum cleaner with a HEPA filter system and rags
soaked in water until wrung until nearly dry. Dispose of used rags with
care to avoid getting dust in the air. Use an approved respirator when
emptying vacuum cleaners and handling used rags.
5.Worker clean-up:Wash your hands before eating, drinking or
smoking. Vacuum your work clothes after use and then launder them
separately, without shaking them, to prevent fiber dust getting into the
air.
Air brakes - inspection and adjustment
A regular schedule for periodic cleaning, lubrication, adjustment and
inspection should be established based on the type of vehicle operation.
It is difficult to predetermine an exact maintenance interval (time or
mileage), since vehicles will be used in a wide variety of applications and
conditions. If you are uncertain of the proper schedule and procedures
for your vehicle, contact your dealer.
Periodic checking of push rod travel or brake adjustment is essential for
effective braking. Push rod travel should be checked every service
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interval to determine if adjustment is necessary. Brake chamber push
rods on original equipment chambers now incorporate a stroke indicator
to aid in adjustment checks; an orange paint marker near the base of the
push rod. If the push rod is clean and the brakes require adjustment, the
orange marker can be seen protruding from the chamber when the
brakes are applied.
Slack adjusters should also be checked to ensure proper operation of the
adjuster mechanism at the six-month interval. Push rod travel should be
kept at a minimum without the brakes dragging.
Inspect the brake lining every maintenance interval. When brake lining or
blocks are worn to within 1/16 inch (1.6 mm) of rivets, brake lining must
be replaced. This inspection or adjustment should only be performed by
a qualified technician and must be in accordance with instructions
provided by the service manual.
Do not back off or disconnect the front brakes so that they are less
effective, letting the rear brakes do all the stopping of the vehicle. Do
not overlook the brakes on the trailer, either. Brake condition on the
trailer is just as important as the tractor. Proper brake balance on trucks
and tractor-trailers is essential for effective braking.
Once a year, the entire brake system must be inspected. Check the
following:
•Any rubber as it may deteriorate whenever used. Rubber brake
components should be inspected by a qualified technician and
replaced as necessary. Replacement intervals vary according to the
severity and length of vehicle service.
•Condition of brake drums, brake chambers and slack adjusters.
•System for air leaks.
•Hose or pipes for rust, damage and deterioration.
•Operation of service and parking brakes.
Some parts such as air brake chamber diaphragm, air compressor and air
cleaner should be inspected periodically and replaced if considered
unserviceable.
Air brakes - air dryer
Performance of desiccant or after-cooler type air dryers is dependent on
climatic conditions in which your vehicle is operating. Maintenance
schedules must be established for each specific operation.
The use of an air dryer on a vehicle does not eliminate the need to
periodically drain the air reservoirs.
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Air brakes - desiccant air dryer
Inspect for moisture in the air system by opening reservoirs, drain cocks
or valves and checking for presence of water. The presence of small
amounts of water due to condensation is normal and should not be
considered as an indication that the dryer is not functioning properly.
The desiccant cartridge should be replaced or rebuilt when it has been
determined that the desiccant is contaminated and does not have
adequate water absorption capacity. The desiccant change interval may
vary; it is generally recommended that the desiccant be replaced every
12 months (yearly). If experience has shown that extended or shortened
life has resulted for a particular installation, then the yearly interval can
be increased or decreased accordingly.
Hydraulic brakes - general inspection and adjustment
A regular schedule for periodic cleaning, lubrication, adjustment and
inspection should be established based on the type of vehicle operation.
It is difficult to predetermine an exact maintenance interval (time or
mileage), since vehicles will be used in a wide variety of applications and
conditions. If you are uncertain of the proper schedule and procedures
for your vehicle, contact your dealer.
Inspect the brake lining every maintenance interval. Establish inspection
intervals that provide for lining replacement before damage to the disc
occurs. Excessive lining wear may expose the backing plate to the disc
causing scoring of the disc faces.
This inspection should be performed by a qualified technician and must
be in accordance with instructions provided by the service manual.
Note:Hydraulic brake system are power assisted. Braking capabilities
will be greatly reduced without engine assist.
Hydraulic brakes - fluid level
Fluid level should be at the bottom edge of the ring on each reservoir fill
port. Do not fill the master cylinder to the top of the reservoir.
Note:If brake fluid requires attention to maintain a proper master
cylinder level, this is an indication of either severe operation (pad wear)
or fluid system leakage. A more frequent and thorough brake inspection
will be required.
Hydraulic brakes - fluid precautions
The HydroMax brake system consists of two completely separate
hydraulic systems operating with two different and incompatible fluids;
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power steering fluid and hydraulic brake fluid. Failure to observe
precautions preventing the contamination of either system with fluid
from the other will result in swelling and deterioration of rubber parts
leading to reduced brake performance and eventual brake failure.
To avoid fluid contamination, the following should always be observed:
1. Use only fluids specified (or equivalent) and properly identified.
2. Add fluids only to the following locations:
•Power steering fluid to the power steering fluid pump reservoir
•Brake fluid to the brake master cylinder
Hydraulic brakes - brake lines, hoses and fittings
Inspect these components every 4,000 miles (6,000 km).
•Check lines for kinks, dents, corrosion or rupture.
•Check hoses for abrasions, kinks, soft spots or rupture, collapse,
cracks, twists or loose frame supports. When replacing a hose, be sure
there is adequate clearance to the hose to avoid an abrasion to the
new hose.
•Examine all connections for leaks.
•Repair or replace brake line tubes, hoses or fittings as required.
Driveline parking brake
Parking brake adjustment should only be performed by a qualified
technician, and in accordance with the instructions in the service
manual.
Use wheel chocks and exercise caution when inspecting under
the vehicle. A vehicle roll-away could result in property damage,
personal injury or death.
Catalytic converter
If your diesel engine is equipped with a catalytic converter, it is
important to review the maintenance schedule to ensure proper
functioning of the catalytic converter. Also, take precautions not to
damage the catalytic converter when servicing your engine or storing
your vehicle.
Note:If your vehicle is equipped with a catalytic converter/muffler,do
notblend waste oil with Diesel fuel. Operate only on low sulfur (less
than 500 parts per million sulfur) diesel fuel with a cetane value of 45 or
higher.
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Note:If your vehicle is equipped with a vertical exhaust pipe, it is very
important to have and maintain a rain cap on the exhaust pipe to
prevent water from entering the exhaust system and catalytic converter.
Any water entering the catalytic converter may damage the catalyst and
affect the function of the converter.
Air induction system
Once each year, perform a complete inspection of the air induction
system. In areas where road salt is used, the inspection consists of
disassembling the joints of each aluminum component and inspecting for
salt build-up, presence of chlorine that can cause aluminum particles to
flake off and enter the engine combustion chambers.
If evidence of corrosion is found (usually at the pipe connections), use a
wire brush to clean the inside of the pipes and inside the rubber hoses.
If the intake pipes are pitted at the joint ends, use Motorcraft Silicone
Gasket and Sealant TA-30 to seal the joints. Be certain that no excess
material is on the inside of the pipes that can be pulled into the engine.
If the service condition of the pipes, hoses or clamps is questionable,
replace the defective part(s).
Be sure that prior to reassembly all dust and debris has been cleaned out
of the pipes and couplings with a clean, damp rag.
To reduce the risk of personal injury or death when performing
maintenance to any turbocharged engine with engine air inlet
piping disconnected, a turbocharger compressor air inlet protective
shield should be installed over the turbocharger air inlet.
Cummins B and Caterpillar engines
Refer to the respective engine operator manual for air filter replacement
procedure.
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.
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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.
To open the hood:
1. Set the parking brake, shift into N (Neutral) (automatic transmission)
or 1 (First) (manual transmission) and turn the engine off.
2. Lift upward on the bottom of
each latch.
3. Pull the bottom of each latch
away from the fender.
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