• A failed compressor in the car's air conditioning makes for miserable summer days.car image by maxuser from Fotolia.com
  
  A failed air conditioning compressor in an automobile causes the entire air conditioning system to fail, leading to hot cars in the summer sun. Modern a/c systems are more complex than those in older cars, and are often regulated by computer, which makes some repairs more expensive and difficult. Simply replacing a compressor in today's automobiles may not be enough.
  
  

Condensers

• When a compressor fails, small pieces of the compressor are spewed into the rest of the cooling system. Changing the compressor fixes the original problem, but does not clean the pieces out of the coolant and other parts of the system where the pieces are trapped. If these pieces find their way back into the condenser, they can cause "black death" -- another compressor failure caused by these black particles from the old compressor. To avoid the problem, replace the parallel flow condenser as well as the compressor.
  
  

From the Bottom

• On many vehicles, it is easier to change the compressor from the bottom of the vehicle rather than trying to reach it from the top. Raising the car up on a jack and removing the right front wheel is necessary to reach the compressor from beneath.
  
  

Filters

• Each air conditioning system will have either an accumulator or a receiver/drier. These parts are different, but are the same in function. They trap, filter out and hold moisture, filter any debris from the system and store excess compressor oil and refrigerant. The desiccants, or water removal agents, in these parts become saturated over time. Also, when a compressor fails, these filters quickly fill up with debris. Just as an oil filter is automatically replaced when the oil is changed, so too an accumulator or receiver/drier should automatically be changed when the compressor is changed.
  
  

Remove Oil

• The oil in an air conditioning system is there only for the compressor. No other components of the system require internal lubrication. All the oil in the system should be flushed and replaced when the compressor is changed. Look for an oil that is not hygroscropic, or in other words, find an oil that does not attract water.