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.
