tire pressure FORD F650 2008 11.G User Guide

Tires should be properly inflated to manufacturers recommended
pressure for the size and service load in which the vehicle is being used.
Refer to the tire manufacturer in which your vehicle is equipped for the
latest information concerning service load and inflation pressure.
It is particularly important to keep moisture from the inside of tires, and
proper selection of air compressor equipment, proper air line routing,
and the use of shop air dryers is strongly recommended to avoid
moisture in the high pressure air used for tire inflation.
Under-inflation
Tires should not be permitted to become under-inflated. Increased
flexing due to under-inflation causes heat build-up within the tire
components. This leads to reduced strength, breakdown of the rubber
compounds, and possible separation of the tire components (i.e., ply and
tread separation and reduced retreadability).
Under-inflation is the primary cause of premature tire concerns including
sudden loss of air. In addition, low inflation causes an increase in rolling
resistance. This results in reduced fuel mileage, a loss in tread mileage,
and uneven wear due to increased tread movement. To determine proper
inflation refer to the tire manufacturer load/inflation guide which can be
found on the tire manufacturer website or at your local truck tire dealer.
Inspection
Check condition of tires for abnormal wear patterns, and proper inflation
pressures. Cut or broken tire casing must be repaired or replaced.
Tires should be inspected for the following conditions. If any are present,
the tire should be removed and repaired, retreaded or scrapped as the
condition indicates.
•Any blister, bump or raised portion anywhere on the surface of the
tire tread or sidewall (other than a bump made by a repair). These
indicate the start of internal separation.
•Any cut that reaches to the belt or ply cords, or any cut that is large
enough to grow in size and depth.
•Any nail or puncturing object.
•If any stone or object is held by a tread groove and is starting to drill
into the tread base, remove the object.
Proper tire inflation, toe-in adjustment, loads, and road speeds are
important factors governing tire mileage, steering ease and
maneuverability.
2008 F-650/750(f67)
Supplement
USA(fus)
Maintenance and Specifications
205

If rib tire is used on front axle and lug or off-road type on rear axle
positions:
1.Front (Steering) Axle:Replace tires at front wheels when tread is
worn to 4/32 inch (3 mm) or less.
2.Rear Axles:Tires must be removed when the tread is worn to
2/32 inch (2 mm) or less. Tires identified with the word “re-groovable”
molded on the sidewall can be re-grooved. A minimum of 3/32 inch
(2.5 mm) of under-tread must be left at the bottom of the grooves.
Wheel and tire balancing
Out-of-round or out-of-balance wheels or tires can cause vehicle
vibration, bounce and shimmy. Replace damaged or out-of-round wheels.
Out-of-round tires and wheel assemblies can be corrected by re-clocking
the tire relative to the wheel.
The tire and wheel assembly should then be dynamically balanced.
Wear
Radial tires can exhibit three types of normal wear patterns: 1) Even,
2) Erosion, 3) Chamfer.
Even wearis a sign that the tire is being properly used and maintained.
Erosion wearhas also been called rolling wear, channel or river wear.
Erosion wear is found more often at free rolling tires. This is an
indication that the tire is being used in a slow wearing operation. What
happens is that the belt plies are held very rigid and the tread is not
allowed to distort as it passes through the contact area. Wear will only
occur at the edge of the tread. No corrective action required. If erosion
gets to be 1/16 inch (2 mm) or more, the tire may be rotated to a drive
axle.
Chamfer or shoulder wear,with tires inflated properly, is a normal
tendency of most radial tire designs. If both inside and outside shoulders
are wearing evenly around the tire, no further action is required.
Over-inflation is not effective in correcting this effect.
Tires: Irregular Wear
If irregular wear is present, check the axle alignment, tire pressure,
wheel balancing, shock and suspension component condition, and wheel
bearing end play.
This condition not only shortens tire life, but will adversely affect the
handling of your vehicle, which is dangerous.
2008 F-650/750(f67)
Supplement
USA(fus)
Maintenance and Specifications
207

Rotating tires from one wheel position to another is a way often used to
even out many types of irregular wear or to avoid it altogether. Some of
the more effective tire rotation programs are:
•Steer tires that have developed some type of irregular wear pattern
can be rotated to drive axles if rib tires are being used on all wheel
positions. Applying steer tires to a drive position will often clean them
and they can be moved back to the steer axles or run out to re-tread
stage on the rear axle.
•Another rotation possibility for fleets with rib tires in all wheel
positions is to break in the new steer tires in the drive axle positions,
then move them to steer axles. This will wear away tread rubber
relatively quickly in the early life of a tire when it is most likely to
develop an unusual wear pattern.
•Drive axle tires may be placed on the other end of the same axle so
that direction of rotation is reversed. This is often helpful if a heel and
toe or alternate lug wear pattern has developed.
Irregular wear can be minimized by:
•Using the right inflation pressure for the load being carried.
•Maintaining proper front wheel alignment -especially toe-in-to
specifications.
•Maintaining proper tire and wheel balance.
•Maintaining shock absorbers and suspension components.
Use of tire chains
Refer to chain manufacturer’s recommendation for correct tire chain
usage, installation and removal.
2008 F-650/750(f67)
Supplement
USA(fus)
Maintenance and Specifications
208

Maintenance Operation Frequency - Observation
Check the engine performance
and the engine governorExcessive engine noise.
Inspect the fan, the fan shroud,
and the fan clutchEngine overheats, fan runs at high
speed constantly, excessive fan noise,
or fan wobble due to worn bearings.
Check for operation of ABS
warning lampAt each engine start up.
Inspect the entire exhaust
system (including inlet pipe,
muffler, outlet pipe and all
exhaust clamps and fasteners)
for holes, leakage, breakage,
looseness and corrosive
damageExcessive noise or the smell of fumes
is experienced.
Inspect the engine air
induction system (including the
air ducts and the air filter) for
loose fitting, damaged or
missing componentsExcessive noise emanates from the
engine compartment.
Inspect the tires and check the
air pressure
(3)Poor steering, wandering or excessive
tire wear.
Balance the wheels and the
tiresVibration or abnormal tire wear
indicates imbalance.
Check the front end alignment
(3)Poor steering, wandering or excessive
tire wear.
Check the transmission and
engine mountings
(2)Hard shifting or excessive vibration.
Check and adjust transmission
controls
(2)High effort to shift or noisy
transmission.
Check fuel pump pressure Insufficient full-throttle power or
backfiring.
Clean radiator cap seal. Clean
and inspect the cap surface on
the radiatorWhen the cap does not hold pressure.
2008 F-650/750(f67)
Supplement
USA(fus)
Scheduled Maintenance Guide
238