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Air Bags and Seat Belts |
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Air bags protected occupants in ways that seat belts alone cannot. The air bag
spreads out the violent impact of a crash and kept occupants from smashing
against the steering wheel, dashboard or windshield. Having an air bag and
wearing an effective seat belt is the best protection. By this, you are
protected from frontal crashes by the air bag -- you are also protected by the
seat belt in all other types of crashes. With an "effective" safety belt, your
body will stop, in a crash, before you hit or go through the windshield and
parts of your car. Seat belts are especially important in small cars, because
your chances of being killed or badly hurt in a collision with a big car is
eight times greater. Wearing your belt will greatly improve your chances of
survival. Air bags can reduce the risk of death in a head-on collision by 26%%
and in all serious accidents by 13%.
Air bags are only useful in frontal crashes, so it is not a good idea to skip
your seat belt because you have an air bag. Air bags provide very effective
protection in frontal crashes, inflating instantly to protect the driver or
passenger that has an air bag. They spread the impact of the crash over the
individual's head and chest and protect fragile body parts from the car's hard
surfaces. Many basic improvements have been introduced into cars in recent
years. These include anti-burst door latches, safety glass, energy-absorbing
steering wheels and columns, head restraints and various seat belt systems. The
benefits of the three-point seat belts have been firmly established: over 50%%
of fatal and serious injuries to car occupants would be avoided if all
occupants wore their seat belts.
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Air Conditioner
Maintenance |
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We all need Air Conditioners in our cars, but there is a
negative side to this too. CFC based refrigerant causes terrible damage to the
ozone layer. Our mechanics will have to make sure that there are no leaks, and
fix them if there are, before they can add any R-12 to our air conditioning
systems. Naturally, this cost will be passed along to us. Recovered refrigerant
will be recycled. Capturing refrigerants and restoring them for reuse is not
only environmentally sound, but mechanically safe. Each molecule of CFC in the
atmosphere has a 120 year life that will destroy tens of thousands of ozone
molecules. This means that a CFC molecule released in 1991 will still be
damaging the ozone layer in 2100. |
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Air Ducts |
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The air ducts control the passage of hot or cold air into the interior of the
car. They are operated by a control on the dash, either manually or
automatically. |
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Air Pump |
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The air pump pumps compressed air into the exhaust manifold and in a few cases
to the catalytic converter. The oxygen in the pressurized air helps to burn
quite a bit of any unburned hydrocarbons (fuel) and thereby converts the
poisonous carbon monoxide into good old carbon dioxide. A belt from the engine
drives the air pump. It has little vanes (thin, flat, curved fins) that draw
the air into the compression chamber. Here, the air is compressed and sent off
to the exhaust manifold where it speeds up the emissions burning process.
Stainless steel nozzles are used to shoot the air into the exhaust manifold,
because they will not burn. Some engines use a pulse air injection system.
Pulses of exhaust gases are used by the system to operate an air pump that
delivers air into the exhaust system. |
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Alternator or Generator |
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The chief source of power of the electrical system is the alternating-current
generator, or alternator. Its shaft is driven by the same belt that spins the
fan and it keeps the engine running. It converts mechanical energy into
alternating-current electricity, which is then channeled through diodes that
alter it to direct current for the electrical system and for recharging the
battery. |
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Ammeter |
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The device is used to determine whether the electrical system is charging,
discharging, or staying "level". The gauge should dip when the engine is
started, then go up as the alternator re- charges the battery. After a few
minutes, it should go to its middle position. |
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Automatic Transmissions |
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Automatic transmission has made driving a lot easier to drive and than manual
transmission. The best part is that you don't have to use a clutch pedal or
gearshift lever. An automatic transmission manages all of this on its own.
Automatic transmissions automatically change to higher and lower gears with
changes in the car's speed and the load on the engine. These transmissions are
also aware of how far down you have pushed the gas pedal, and shift
accordingly.
The output shaft turns the governor. The rolling of the governor is directly
proportional to the speed of the car. The centrifugal force from the governor
sends the oil is sent from the pump to the shift valves. The shift valves then
move out sending the transmission fluid to the gear shifting mechanisms in the
transmission. When the car slows down, the valves move in and send the
transmission fluid in the opposite direction, thus changing the gears. The
different gears are selected by routing the pressure to the clutches and brake
bands. |
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