All special aspects of car air conditioner servicing. Why and when diagnostics of AC should be carried out. What measures can prevent possible failures? What kind of damages can be detected in the course of diagnostics?

Answers to the most important questions concerning operation failures of vehicle AC are provided below.

Methods of AC compressor diagnostics

Vehicle air conditioners are subjected to heavy mechanical stresses: change of temperature, operation in severe environmental conditions (dampness, dust, dirt). That is why diagnostics of vehicle air conditioners is in great demand.

What equipment is used for diagnostics?

All air conditioners have similar operation principle. When the air conditioner is on, freon is being compressed. While it is powered off, freon is in gaseous form. Being under pressure, freon heats up and flows to a condenser where it cools down into liquid condition. Then freon passes to the receiver-drier, and after being purified, flows to the air-conditioning evaporator. Prior to that, freon passes through thermoregulating valve (TRV) which lowers pressure of the liquid and therefore cools it down. From the evaporator freon is transported back to the compressor.

Operation principle of any air conditioner implies that cooling agent circulates in a hermetically sealed space. Break of airtightness leads to freon leakage and may cause a serious damage to the air conditioner. Experienced specialists agree that air conditioner servicing is a hard and complex process. That’s why all the manipulations can be done to the air conditioner only after the diagnostics. A service center should have professional equipment for diagnostics of damages.

MS111 bench test is used for diagnostics of piston, axial piston, rotary and scroll compressors of climate systems. Small auto workshops most often use small-size and multifunctional MS211 tester. This tester is good for diagnostics of electromagnetic clutch and electromagnetic valve of a compressor.

What kind of damages can be detected?

Following operational problems can be detected during AC diagnostics:

• poor tightness of air conditioner;
• mechanical seizure of auto compressor;
• electrical problems;
• impassible system;
• extreme pressure;
• faulty choke valves, contamination of cabin air fine filter.

If a damage of any of AC detail, unit, or part has been detected, the problem is to be solved as soon as possible. Late repair of one unit can result in more serious damage and in eventual break down of air conditioner itself.