Ford Thunderbird (2004 year). Manual — part 48

Use the recommended cold inflation pressure for optimum tire
performance and wear. Under-inflation or over-inflation may cause
uneven treadwear patterns.

Under-inflation is the most common cause of tire failures and
may result in severe tire cracking, tread separation or

⬙blowout⬙,

with unexpected loss of vehicle control and increased risk of injury.
Under-inflation increases sidewall flexing and rolling resistance,
resulting in heat buildup and internal damage to the tire. It also may
result in unnecessary tire stress, irregular wear, loss of vehicle control
and accidents. A tire can lose up to half of its air pressure and not
appear to be flat!

When weather temperature changes occur, tire inflation pressures also
change. A 10 degree temperature change causes a corresponding drop of
7 kPa (1 psi) in inflation pressure. Check your tire pressures frequently
and adjust them to the proper pressure which can be found on the tire
label or certification label.

If checking tire pressure when the tire is hot, (i.e. driven more than 1.6 km
[1mile]), never “bleed” or reduce air pressure. The tires are hot from
driving and it is normal for pressures to increase above recommended cold
pressures. A hot tire at or below recommended cold inflation pressure
could be significantly under-inflated.

To check the pressure in your tire(s):

1. Make sure the tires are cool, meaning they are not hot from driving
even a mile.

Note: If you have to drive a distance to get air for your tire(s), check
and record the tire pressure first and add the appropriate air pressure
when you get to the pump. It is normal for tires to heat up and the air
pressure inside to go up as you drive. Never “bleed” or reduce air
pressure when tires are hot.

2. Remove the cap from the valve on one tire, then firmly press the tire
gauge onto the valve.

3. Add air to reach the recommended air pressure

Note: If you overfill the tire, release air by pushing on the metal stem in
the center of the valve. Then recheck the pressure with your tire gauge.

4. Replace the valve cap.

5. Repeat this procedure for each tire, including the spare.

Note: Some spare tires require higher inflation pressure than the other
tires.

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6. Visually inspect the tires to make sure there are no nails or other
objects embedded that could poke a hole in the tire and cause an air
leak.

7. Check the sidewalls to make sure there are no gouges, cuts, bulges or
other irregularities.

Tire and wheel alignment

A bad jolt from hitting a curb or pothole can cause the front end of your
vehicle to become misaligned or damage to your tires. If your vehicle
seems to pull to one side, vibrate or shake when you’re driving, the
wheels may be out of alignment. Have a qualified technician at a
reputable repair facility check the wheel alignment periodically.

Wheel misalignment in the front or the rear can cause uneven and rapid
treadwear of your tires and should be corrected by a qualified technician
at a reputable repair facility. Front wheel drive (FWD) vehicles, and
those with independent front suspension require alignment of all four
wheels.

The tire should also be balanced periodically. An unbalanced tire and
wheel assembly may result in irregular tire wear.

Tire rotation

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197

• Front Wheel Drive (FWD)

vehicles (front tires at top of
diagram)

• Rear Wheel Drive (RWD)

vehicles/Four Wheel Drive (4WD)
vehicles (front tires at top of
diagram)

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198

Sometimes irregular tire wear can be corrected by rotating the tires.

Note: If your tires show uneven wear ask a qualified technician at a
reputable repair facility to check for and correct any wheel misalignment,
tire imbalance or mechanical problem involved before tire rotation.

Tire wear

Measure and inspect the tire tread on all your tires periodically.
Advanced and unusual tire wear can reduce the ability of tread to grip
the road in adverse (wet, snowy, etc.) conditions. Visually check your
tires for uneven wear, looking for high and low areas or unusually
smooth areas. Also check for signs of tire damage.

When the tread is worn down to 4
mm (1/16th of an inch), tires must
be replaced to prevent your vehicle
from skidding and hydroplaning.
Built-in treadwear indicators, or
“wear bars”, which look like narrow
strips of smooth rubber across the
tread will appear on the tire when
the tread is worn down to 4mm (1/16th of an inch). When you see these
“wear bars”, the tire is worn out and should be replaced.

Inspect your tires frequently for any of the following conditions and
replace them if one or more of the following conditions exist:
• Fabric showing through the tire rubber
• Bulges in the tread or sidewalls
• Cracks or cuts on the sidewalls
• Cracks in the tread groove
• Impact damage resulting from use
• Separation in the tread
• Separation in the sidewall
• Severe abrasion on the sidewall
If your vehicle has a leak in the exhaust system, a road tire or the spare
tire may be exposed to hot exhaust temperatures requiring the tire to be
replaced.

Safety practices

Driving habits have a great deal to do with your tire mileage and safety.
• Observe posted speed limits

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