CHANGING THE ENGINE AIR
FILTER - 6.8L
WARNING
To reduce the risk of vehicle damage
and personal burn injuries, do not
start your engine with the air cleaner
removed and do not remove it while the
engine is running. Note:
Operating your vehicle in heavy
snowfall or extreme rain conditions may
allow excessive amounts of snow or water
into the air intake system. This could plug
or soak the air filter that could cause the
engine to lose power or shut down.
When replacing the air filter element, use
a Motorcraft® air filter element. See
Motorcraft Parts (page 252).
Note: Failure to use the correct air filter
element may result in severe engine
damage. Resulting component damage
may not be covered by the vehicle Warranty.
Change the air filter element at the correct
interval. See
Scheduled Maintenance
(page 314). 1. Locate the mass air flow sensor
electrical connector on the air outlet
tube. Disconnect the mass air flow
sensor electrical connector. 2. Reposition the locking clip on the
connector (connector shown from
below for clarity), squeeze the
connector and pull it off of the air
outlet tube. 3.
Clean the area from around the air tube
to the air cover connection to prevent
debris from entering the system. Next,
loosen the bolt on the air tube clamp
so the clamp is no longer snug to the
air tube. It is not necessary to
completely remove the clamp.
4. Pull the air tube off from the air cleaner
housing.
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5. Remove the clips that secure the air
filter housing cover. Push the air filter
cover toward the center of the vehicle
and up slightly to release it.
6. Remove the air filter element from the
air filter housing.
7. Install the new air filter element.
8. Engage the clips to secure the air filter housing cover to the air filter housing.
Be careful not to crimp the filter
element edges between the air filter
housing and cover. Ensure that you
align the tabs on the edge properly into
the slots.
9. Slip the air tube onto the air filter housing and tighten the air-tube clamp
bolt snugly. Do not over tighten
air-tube clamp bolt. 10. Reconnect the mass air flow sensor
electrical connector to the outlet
tube. Make sure the locking tab on
the connector is in the locked position
(connector shown from below for
clarity).
CHANGING THE ENGINE AIR
FILTER - 6.7L DIESEL
Air Filter Restriction Gauge WARNING
To reduce the risk of vehicle damage
and/or personal burn injuries do not
start your engine with the air filter
removed and do not remove it while the
engine is running. Note:
Operating your vehicle in heavy
snowfall or extreme rain conditions may
allow excessive amounts of snow or water
into the air intake system. This could plug
or soak the air filter that could cause the
engine to lose power or shut down.
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The restriction gauge, located on the upper
housing of the air filter assembly, measures
the vacuum inside the air filter. The more
the air filter is restricted (dirty, clogged),
the higher the vacuum reading.
Check the air filter restriction gauge
whenever you open the hood to perform
general engine maintenance or at least
every 7,500 miles (12,000 km). If you
operate your vehicle in extremely dusty
conditions, check and reset the gauge at
least every 500 miles (800 km), or two
weeks, whichever comes first. Change the
air filter when the restriction gauge reads
near the change filter line and the gauge
is yellow. If you allow the restriction gauge
to reach maximum restriction you can
affect your engine performance and fuel
economy.
Note:
Do not blow out the air filter element
with compressed air since the compressed
air could damage the filter paper.
Note: Do not rely on filter appearance
alone. A filter which appears to be dirty may
actually have several thousand miles
(kilometers) of life remaining. After installation of the new filter element,
reset the gauge by pressing the reset
button on top of the gauge.
The following actions are recommend after
operating the vehicle up to 200 miles (320
km) in heavy snowfall or extreme rain:
•
Snow: At the earliest opportunity, open
the hood and clear all the snow and ice
from the air filter housing inlet (do NOT
remove the foam filter) and reset the
air filter restriction gauge.
• Extreme rain: The air filter will dry after
about 15– 30 minutes at highway
speeds. At the earliest opportunity,
open the hood and reset the air filter
restriction gauge.
Air Filter Replacement
When replacing the air filter element, use
a Motorcraft® air filter element. See
Motorcraft Parts (page 253).
Note: Failure to use the correct air filter
element may result in severe engine
damage.
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3. Reinstall the lower portion of the
housing by slowly turning it clockwise
onto diesel fuel conditioner module
housing, allowing fuel to soak into the
fuel filter element. Tighten the lower
housing until it contacts the
mechanical stop.
Note: The engine will not run properly if you
do not install the diesel fuel conditioner
module fuel filter in the housing or if the
filter bowl is not tightened to the
mechanical stop.
Note: You will need to purge the system of
air after removal or changing of the filter.
See Purging Air from the Fuel System later
in this chapter.
Engine-mounted Fuel Filter
Removal
The engine-mounted fuel filter is a plastic
disposable cartridge. 1.
Disconnect both fuel lines by squeezing
the connector tabs and pulling the lines
straight off. Note:
Although the fuel system is not fully
pressurized when the vehicle is off, some
residual pressure may remain in the fuel
system since it can take some time for the
pressure to completely bleed off. Therefore,
we recommend you place a shop rag below
the filter connectors to absorb the small
amount of fuel that will drain.
2. Rotate the filter fully counterclockwise
until the peg is at the far end of the slot.
3. Pull the filter straight up from the bracket and discard the filter.
Installation
1. Install the new filter into the filter bracket. Turn the filter clockwise to
lock it in place.
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2. Reconnect both fuel lines.
Note:
Using a fuel that has more than
average impurities may require you to
replace the fuel filter more frequently than
the service interval specifies.
Note: You will need to purge the system of
air after removal or changing of the filter.
See Purging Air from the Fuel System later
in this chapter.
Purging Air from the Fuel System
Turn the ignition key to on for 30 seconds,
then turn it to off. Do this six times in a row
to purge any trapped air from the fuel
system.
After filter service, a no start or rough
running engine may indicate that air is
entering the system through the filter bowl
seal or drain. Make sure the drain is tight
and you tightened the filter bowl to the
mechanical stop.
ELECTRICAL SYSTEM
INSPECTION
Periodically inspect electrical connectors
on the outside of the cab and on the engine
and frame for corrosion and tightness.
Exposed terminals, 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 Dielectric 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 powertrain components,
such as engine and transmission controls,
instrument panels and ABS. While most
systems operate on battery voltage (12
volts), some systems can be as high as 90 volts or as low as five volts. See the
Electrical Circuit Diagram Manuals,
available from your vehicle
’s manufacturer,
to make sure that any extra body lights and
accessory connections to circuits are both
appropriate and not overloaded. Do not
make modifications to any vehicle control
system without first contacting an
authorized dealer.
AIR INDUCTION SYSTEM
INSPECTION WARNING
When performing maintenance to
any turbocharged engine with engine
air inlet piping disconnected, keep
loose clothing, jewelry and long hair away
from the engine air inlet piping. A
turbocharger compressor air inlet
protective shield should be installed over
the turbocharger air inlet to reduce the risk
of personal injury or death. Perform a complete inspection of the air
induction system annually.
In areas where road salt is used,
disassemble the joints of each aluminum
component and inspect for salt build-up
and 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 pitting is evident at the joint ends of the
intake pipes, use Motorcraft Silicone
Gasket and Sealant TA-30 to seal the
joints. Make sure no excess material, which
can pull into the engine, is on the inside of
the pipes. If the service condition of the
pipes, hoses or clamps is questionable,
replace the defective part(s).
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Your vehicle is equipped with
non-asbestos brake linings. However,
exposure to excessive amounts of brake
material (whether asbestos or
non-asbestos, fiberglass, mineral wool,
aramid or carbon) may be a serious health
hazard.
Air Brakes
WARNING
Do not manually adjust the
automatic slack adjusters to correct
excessive push rod stroke as it may
result in reduced brake effectiveness and
a vehicle crash. Excessive push rod stroke
indicates that a problem exists with the
automatic adjuster, with the installation
of the adjuster, or with foundation brake
components that manual adjustment does
not remedy. Seek service from a qualified
facility for excessive push rod stroke. Inspection and Adjustment
Establish a regular schedule for periodic
cleaning, lubrication and adjustment
inspection based on vehicle use. Exact
maintenance intervals are difficult to
predetermine due to vehicle applications
and operating conditions. If you are
uncertain of the proper schedule for your
vehicle, contact an authorized dealer.
Regular inspections should include:
•
Periodic checking (every service
interval) of push rod travel or brake
adjustment. This is essential for
effective braking. Brake chamber push
rods on original equipment chambers
now incorporate an orange paint
marker near the base of the push rod as a stroke indicator to aid in
adjustment checks. If the push rod is
clean and the brakes are out of
adjustment, you can see the orange
marker protruding from the chamber
when the brakes are applied.
• Checking the brake lining (every service
interval). When brake linings or blocks
wear within 0.063 in (1.6 mm) they
must be replaced.
• Periodic checking (every service
interval) of the air compressor filter.
Check the filter minder and when the
indicator is near or on the red line
marked
Service, replace the filter and
reset the service filter minder.
Do not back off or disconnect the front
brakes so that they are less effective,
letting the rear brakes do all the stopping
of your 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, inspect the entire brake
system:
• Rubber components for deterioration.
A qualified technician should inspect
these components and replace them
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.
Periodically inspect parts such as air brake
chamber diaphragm, air compressor and
air cleaner. Replace any parts if you can
consider them unserviceable.
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Air Dryer
Climactic conditions affect performance
of desiccant or after-cooler type air dryers.
You must establish a maintenance
schedule for each specific operation.
The use of an air dryer on a vehicle does
not eliminate the need to drain the air
reservoirs periodically.
Inspect for moisture in the air system by
opening reservoirs, draincocks or valves
and checking for presence of water. The
presence of small amounts of water due
to condensation is normal and is not an
indication that the dryer is not functioning
properly.
Replace or rebuild the desiccant cartridge
when you determine that the desiccant is
contaminated and does not have adequate
water absorption capacity. The desiccant
change interval may vary. A general
recommendation is to replace the
desiccant 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.
Draining the Air Brake Reservoir
WARNING
Failure to drain air brake reservoirs
can result in a reduction or loss of
braking ability due to fluid
accumulation in the reservoir and/or
possible freeze-up during cold weather. Completely drain all the air brake reservoirs
daily by opening the draincock at the ends
of the tanks. (Where accessible.
Pull-chains are used when the drains are
undercab or otherwise inaccessible.) Close
the draincock after draining. Manually drain any air tanks equipped with automatic
moisture ejector valves, as required, to
maintain a dry air system. Contact an
authorized dealer if you are unsure of the
air reservoir locations or the draining
procedure.
Hydraulic Brakes
Establish a regular schedule for periodic
cleaning, lubrication and adjustment
inspection based on vehicle use. Exact
maintenance intervals are difficult to
predetermine due to vehicle applications
and operating conditions. If you are
uncertain of the proper schedule for your
vehicle, contact an authorized dealer.
Regular inspections should include:
•
Checking the brake lining (every service
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. A qualified
technician should perform this
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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 equals ½ steer axle
loading).
Special applications may warrant a setting
based on experience with the type of tire
operating loads and conditions. Radial tires
are more sensitive to toe-in setting than
bias ply tires. Fine tuning school bus
alignment to line-haul truck standards
does not drastically improve tire tread life.
STEERING SYSTEM
INSPECTION
WARNING
Failure to maintain the steering
system in proper condition can cause
reduced steering ability resulting in
property damage, personal injury or death. Note:
Have any steering problems
immediately corrected by a qualified service
technician.
Ask your service technician to examine the
steering mechanism. Only minor
adjustments may be necessary.
Regular inspections should include:
• Checking the tie rod, drag link end
clamp bolts and ball joints for proper
tightness.
• Checking for installation and spread of
cotter pins and tightness of nuts at
both ends of the tie rod and drag link.
• Checking that the pitman arm (steering
arm at steering gear) mounting is tight
and locked. Check system for leaks or
hose chafing. Repair immediately, if
necessary. •
Maintaining proper steering gear and
power steering pump lubricant levels.
• Checking steering column joint bolts
and steering linkage, particularly for
body-to-chassis clearance.
Steering Column Joint Bolts
As a good maintenance practice, check
steering column joint bolt tightness every
60,000 mi (96,000 km) or annually,
whichever occurs first. Do not overtighten
the bolts.
Hydraulic System
Whenever draining and refilling the power
steering's hydraulic system for any reason,
bleed air from the system before returning
the vehicle to service. Failure to bleed the
hydraulic system properly can result in
degradation of power system performance.
Consult an authorized dealer who is aware
of the proper procedures for filling and
bleeding the system.
SUSPENSION SYSTEM
INSPECTION
Note: Do not adjust air suspension height
to any setting other than the specified
setting. Altering the height setting changes
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
oil change intervals.
Periodically check:
• Condition of spring leaves for evidence
of fatigue, bending or breakage.
• Condition of suspension mounting
brackets and bushings.
• Torque rod mounting fasteners for
tightness.
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