【 Weak current College 】 auto air-conditioning maintenance and upkeep of 】

1. maintenance of method 1, failure phenomenon: the compressor is not closing, the air conditioning system is not operational, the system does not have the pressure.
Cause: all refrigerant leaks.
Solution: identify the leakage point (pipeline blistered, pipe rupture, condenser tube sealing ring worn, the pressure switch is not tightened has loose, expansion valve damage disclosure, damage to the compressor and the insurance piece has expired) after the replacement of a defunct parts, and then make the vacuum, pressure, air conditioning system of charge charging refrigerant, failure to discharge. 2, the symptom: compressor suction, the air conditioning system refrigerant, the compressor discharge pipe surface temperature is very high (hot) expansion valve and the pipe surface temperature is the temperature, high-pressure compressor does not change after the pick-up, but low pressure is very low.
Cause: the expansion valve sensor head worn, seal of refrigerant leakage, resulting in full expansion valve valve hole close to realization of refrigerant cycle.
Solution: replace the expansion valve, and then make the vacuum, pressure, air conditioning system of charge charging refrigerant, failure to discharge. 3. failure phenomenon: the compressor is not closing, the air conditioning system is not operational, system balance pressure normal (0.5 ~ 0.7MPa).
Cause: the failure of air conditioning system, air conditioning insurance tablets relay failure, thermistor clues bad or broken, compressor connection leads poor contact, condenser e fan connection leads poor contact.
Solution: on the zero of checks on the failure to replace parts and components, exhaust failure. 4, the symptom: air conditioning system operating normally, conditioners, and lack of outlet air flow fan noise, evaporator with frost.
Cause: the air box channel has no dust filters wind resistance, blocking.
Solution: remove the evaporator core and filter cleaning (once a year), andthen reassemble, installation on completion of the vacuum, pressure, air conditioning system of charge charging refrigerant, failure to discharge. 5, the symptom: air conditioner is operating normally, the air conditioning cooling effect, high pressure and low pressure are too high.
Cause: the air conditioning system refrigerant charging of excessive or compressor lubricants add too many.
Solution: should be recycled refrigerant release excessive compressor lubricant, and then make the vacuum, pressure, air conditioning system of charge charging refrigerant, failure to discharge. 6. failure phenomenon: the air conditioning works, use after a period of increasing cooling efficiency is not good, high pressure and low pressure is low.
Cause: the car is running after the pipeline vibration of each connector parts loose phenomenon, leakage of refrigerant chronic.
Solution: reset the connector screw, and then make the vacuum, pressure, air conditioning system of charge charging refrigerant, failure to discharge. 7. failure phenomenon: when the air conditioning running all normal, but after some time a significant drop in the refrigeration effect until no refrigeration, high pressure is high, and low pressure is very low (≤ 0.05MPa), stopped for a period of time before starting and back to normal, over time and repeat the last phenomenon.
Cause: the expansion valve ice jam.
Solution: replace dry filter, and then rerun the vacuum, pressure, air conditioning system of charge charging refrigerant, failure to discharge. 8, symptom: air-conditioning systems run 10 minutes later, the air outlet temperature is high, refrigeration, and low pressure too high, the compressor has a rattle.
Cause: the expansion valve failure.
Solution: replace the expansion valve, and then make the vacuum, pressure, air conditioning system of charge charging refrigerant, failure to discharge. 9, symptom: air conditioning system operating normally, conditioners, and lack of outlet air flow fan noise increases, the compressor frequent starting off.
Cause: the air box channel has no dust filters wind resistance increase, blocked, this is to prevent the evaporator surface frosting and cut off the compressor.
Solution: remove the evaporator core and filter cleaning (once a year), and then reassemble, installation on completion of the vacuum, pressure, air conditioning system of charge charging refrigerant, failure to discharge. 10, symptom: air-conditioning system, low pressure too high, and high-voltage side pressure gauge pointer slower swing, swing, compressor exhaust pipe surface temperature is high (hot).
Cause: the air conditioning system with air mixed in.
Solution: after recovering refrigerant again, to vacuum up the vacuum degree requirements, holding, press the empty. II. maintenance of air conditioning system, air conditioning system 1 common parameters refrigerant HFC-134a refrigerant: filling volume: 380g ± 10% of the compressor refrigeration lubricants: dedicated PAG lube system vacuum: vacuum gauge pressure ≥ 740mmHg low pressure 0.1 ~ 0.2MPa 2, maintenance ① in the winter, automotive air conditioning system stops running, the air conditioning system should also be regularly every two weeks starting work 5min above. ② should always check whether clean condenser surface, there are sundries and Earth surface attached to the condenser, the water used for cleaning, you should be careful not to damage the condenser fins. ③ air condition in the filter should be the first week after removal for cleaning, evaporator core should first year in the professional maintenance depot for disassembly cleaning. ④ regular professional maintenance station to adjust the compressor belt tension. 3. air conditioning system repair performance detection step 1, Setup repairs completed for Visual inspection, shall be clear is to repair the automobile air conditioning in the insulation, air distribution inside the car, the temperature differences are not detection, detection is used to measure its high pressure valve, low pressure value and measurement with temperature controller air-conditioning outlet temperature. 2, the first will use special filling machine or vacuum pumps, valves and systems connected to the table. 3, systems, vacuum, vacuum reach vacuum gauge pressure ≥ 740mmHg (use the vacuum pump pumping 2L 20min above), the high end and low end while vacuum. 4, system pressure 5min, such as a table-no change in the description of the system without leakage, you can proceed to the nextAction, such as a table there is a clear change description needle system leaks point, find the leak, and then on the action. 5, from low-voltage charging refrigerant HFC-134a endorsement —, 380g ± 10%. 6. remove the high-pressure side, start the engine and the air conditioning system that controls the engine speed in 3500r/min, air conditioning system will connect the tubes after 2min in cold preparations inhalation system. 7. measurement of outlet temperature of 8 to 12 ° c. 8. remove the connecting pipe fitted with a dust cover.