Air
Conditioner Maintenance
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.
Air Ducts
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.
Air Pump
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.
Alternator
or Generator
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.
Ammeter
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.
Automatic
Transmissions
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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