The System

• Picture of unit
• How does an air conditioning system work?
• Should the air conditioning be turned off each time the engine is turned off?

• What are some of the indictors of a system needing service?
• What should an air conditioning system service consist off?
• Steps to inspecting the AC system 
• Steps to servicing the air conditioning system
• What is the best time of the year to service an AC unit?
• Fundamentals of pressure
• Terms used when servicing
• What do gauges readings mean?
• How much refrigerant does the system hold?
• Can an AC system be serviced by pressures and air delivery temperature?
• If the system has a sight glass, can it be used?
• What engine RPM should the engine be run at for air conditioning service and testing?
• Pressure temperature chart
• Is there another method to test a system for operation?
• What is superheat?
• How is servicing done by the superheat method?
• How is charging by the subcooling method done?
• System temperature check points
• Sub cooling chart
• Can using the bare hands check line temperature?
• How can the pressures read what they should and have no cold air delivery?
• What are some of the tricks of servicing?
• Are there any other checks should be done after service is completed?

• How many ways are there to check for leaks?

• What is ambient temperature and its effect on refrigerant?
• What is retrofit and what refrigerant should be used?
• Are operating pressures higher on R-134a than R-12 systems?

• How does refrigerant become contaminated?

• How can refrigerants be identified for contamination when using  recycled refrigerant?
• How does air get into an AC system and become a contaminate?
• What are the dangers of handling refrigerants?

• What causes a compressor to fail?
• What is a variable displacement compressor?
• Compressor checks
• System oil capacity chart
• Establishing oil levels
• Watch it burn
• How can a test be done to determine if a reed valve is broken or leaking?
• Does the compressor need to be replaced just because the clutch burned out or the reverse?
• Are replacement compressors shipped with oil in them?
• Why does a compressor fail after a repair has been made?
• When are noisy compressor not a bad compressor?
• Can a cycling switch cause a compressor to fail?
• On water pump driven fan blades, can the blade cause compressor failure?
• Can heavy-duty radiators cause compressors to fail?
• What causes a compressor to blow a hole in the side of it?
• What causes a clutch to fail?
• What is a clutch saver switch and where should it be located?
• What does burnishing a clutch mean?
• Clutch failure checkout list
• Clutch ground circuit

• What kind of oil should be used in the system?
• What is the best method to install oil into the system?
• How is excessive oil removed from the system?
• When topping off a system, should oil be added to the system?
• When is it necessary to attach a label as to what refrigerant and oil is in the system?

• Must a system be evacuated before servicing?
• What is the proper method to connect and use an evacuation pump?
• Vacuum chart

• What must be done to prepare a system for repair?
• Is it necessary to flush a system when doing repairs?
• What is the procedure called "live flushing"?
• What is closed loop flushing?
• Flushing the CCOT system
• Flushing the TXV system

• What are some little known facts about a condenser?
• What are the signs of a restriction in the condenser?
• Is there such a thing as forming a gradual restriction in the condenser?
• When would it be nearly mandatory to replace to condenser?
• What is a sub cool condenser?
• Condenser designs
• Temperature testing work sheet

• What is a cycling clutch orifice tube?
• How does an cycling clutch orifice tube fail?
• What is a variable orifice valve?
• Can an orifice tube be put in backwards?
• How can a test for an orifice tube o-ring bypassing or if the orifice tube left out?
• How does an expansion valve work?
• How does an expansion valve fail?
• Is there more than one reason to read superheat?
• What causes a restriction in the expansion valve?
• How can the different expansion valves be identified?

• Can there be a restriction in the accumulator?
• Can there be a restriction in the receiver dryer?
• Can there be contamination in a muffler?

• How is temperature read correctly?
• Diagnosing the system (flow chart)
• System diagram with temperature points
• Temperature testing work sheet
• Is it possible to have a fifty degree drop across the condenser and not have a restriction?
• Is it possible to have the correct drop across the condenser but read higher than the outside temperature dictates it should be?
• What is the best method to diagnose duel AC units?

• What is a clutch cycling switch and how does it work?

• How do AC hoses fail?
• Ford AC hose assemblies
• Are aftermarket AC hoses as good as OE?

• How do screw type service valves work?
• Bulletin, refreshing ATC memory
• Bulletin, Honda grounds
• What causes water to run on the floor after the AC has been run for a time?
• Clutch ground circuit

• Fans
• What are bottom breathers
• What is the purpose of air dams and engine compartment seals?
• How do you test for a bad fan clutch?
• Can an electric motor on the radiator be wired backwards?
• How can an electric motor or clutch have current to it and still not work?
• Can Ford spring lock fittings be stopped from leaking?

• On vehicles that have evaporator regulator valves, can they be retrofitted with replacing the valves?

• What is wrong when an AC system is cold at slow speeds and gets warmer at highway speeds?
• What causes a system to get cold quickly when vehicle is cold but takes much longer when vehicle has been setting in the sun?
• What is wrong when the AC operates properly for a long period, and all of a sudden, the air turns hot?
• What is the reason the AC gets colder with R-12 in the system rather than R-134a?
• What would cause an AC system to operate off and on, depending on the time of day the car is driven and how it is driven?
• Is there a simple method to diagnose an AC system?