Air conditioning system
Attention! The air conditioning system is constantly under high pressure. Never disconnect refrigeration lines or remove any system components without first discharging the system. The discharge of the air conditioning system must be carried out by an experienced specialist in a car service workshop. Always wear safety goggles when disconnecting refrigerant lines!
Attention! When replacing air conditioning system components, a certain amount of replacement refrigerant oil will be required to fill the volume of the new assembly. Use only oil suitable for use in R-134a systems (read the label on the container carefully).
Service
The following checks should be carried out on a regular basis to keep the air conditioning system in good working order:
- a) Check the condition of the compressor drive belt. If defects or signs of wear are found, replace (see chapter Current service);
- b) Check drive belt tension, adjust if necessary (see chapter Current service);
- c) Check the refrigeration hoses for cracks, swelling, signs of hardening and aging of the rubber. Replace if necessary;
- d) Check the condenser plates for insect remains, old leaves, and other debris stuck between them. If necessary, clean the gaps with a thin brush, or blow them with compressed air;
- e) Check system charge level;
- f) If water drips are found on the floor mats under the instrument panel, remove the condensate drain pipe from the evaporator casing (located in the lower front corner) and a piece of wire, check the patency of both holes (see accompanying illustration).
The air conditioning system must be switched on for at least 10 minutes at least once a month (even in the winter season). Prolonged inactivity of the A / C leads to hardening and failure of the sealing rings and cuffs of the connecting path.
Note. When the deicing function is activated, the A/C compressor is activated.
In case of irregularities in the operation of the A/C, first of all check the correct operation of the compressor clutch (see Check of an electric chain of coupling of coupling of the compressor K/V).
Due to the complexity of the system design and the need to use special equipment, its maintenance, in-depth diagnostics and refurbishment are beyond the qualifications of an average amateur mechanic and must be carried out in a car service workshop. Only the simplest checks and replacements listed below in this manual fall within the competence of the car owner.
The most typical cause of a malfunction in the functioning of the A/C is a decrease in the charge level of the refrigerant oil. The following simple checks will quickly identify signs of a low refrigerant level.
Examination
1. Warm up the engine to normal operating temperature.
2. Turn on the A/C for maximum cooling capacity. Select the maximum fan speed. Open the doors to prevent closed air circulation in the cabin.
3. Insert the thermometer into the outlet air duct through the central vent on the instrument panel (see accompanying illustration). When the A/C is switched on, the temperature of the air coming out of the deflector must lie within 2°С÷8°С. In very hot weather (40°С), it is permissible to increase the outlet temperature up to 15°C, but no more.
4. If the requirements listed in the previous paragraph are not met, then the system needs to be charged. For a more detailed diagnosis of the state of the system, the car should be driven to a specialized workshop.
Adding refrigerant
Attention! To charge the air conditioning system of the vehicles covered in this manual, use only refrigerant oil R-134a.
1. Prepare the standard charger kit R-134a (ask at car accessories stores). The set includes a bottle of refrigerant oil, a valve nozzle and a piece of hose connected between the valve and the fitting of the low-pressure part of the refrigeration tract (see accompanying illustration). Since one can of oil may not be enough to fully charge the system, it makes sense to buy a couple at once just in case. Make sure that at least one of the cans has a little red tint, which will allow you to quickly identify refrigerant leaks if they occur.
Attention! Never fill the system with more than two cans of refrigerant!
2. Connect the charging kit to the system according to the manufacturers instructions. The design of the fitting connections allows the set to be connected only to the low-pressure part of the system.
Attention! Do not attempt to connect the kit to the fitting of the high-pressure part of the duct!
3. Close the valve on the adapter and screw the adapter onto the cartridge head, making sure that the o-ring/rubber gasket is present.
Attention! Be sure to wear safety goggles!
4. Remove the dust cap from the fitting of the low-pressure part of the refrigeration circuit and connect the hose of the charging set equipped with a quick connection to it (see accompanying illustration).
5. Warm up the engine and turn on the A/C. Ensure that the charging kit hose does not come into contact with the engine cooling/air conditioning fan blades.
Note. Charging the system must be done with the compressor running. If the compressor clutch disengages, the system should be switched to maximum cooling capacity and all passenger compartment doors should be opened.
Note. To prevent the compressor from turning off during charging, disconnect the connector from the low pressure switch (some models use a combination low/high pressure switch) and bridge it with a paper clip or piece of wire.
6. Rotate the valve nozzle to pierce the head of the cartridge, thereby opening the refrigerant supply (you should hear the characteristic sound of escaping gas). During the entire charge, hold the can strictly upright, shaking it from time to time. Between two series of charging, pause as necessary to stabilize the system.
7. If you have an accurate thermometer at hand, insert it through the deflector into the central A/C air duct and monitor the temperature of the air supplied to the passenger compartment using it (see paragraph 3 "Checks").
8. When the cartridge is empty, close the valve and disconnect the hose from the system's low-pressure fitting. Replace the dust cap immediately.
9. Disconnect the valve nozzle from the cartridge, if necessary, move it to the second cartridge and continue filling. Upon completion of the procedure, place the unfinished cartridge upright on the rack and use it as needed to recharge the system.
Heating system
1. Wetting of the carpet on the floor under the heater heat exchanger, or steam escaping through the air duct deflectors, indicates leaks in the heater heat exchanger. Remove heat exchanger (see Replacing the heater heat exchanger) and replace it with a new one (the heater heat exchanger cannot be repaired).
2. If the heater does not provide heating of the air supplied to the passenger compartment, the reason for such a failure may be one of the following:
- a) The thermostat is stuck in the open position, which allows the engine coolant supplied to the heat exchanger of the heater to heat up to the proper temperature;
- b) There is a violation of the patency of the cooling tract, which blocks the supply of coolant to the heater heat exchanger. Feel the hoses connected to the nozzles on the rear bulkhead of the engine compartment - both of them must be hot, otherwise the patency of the tract is broken (blocked hoses, heat exchanger, or heater control valve). Disconnect the hoses and reverse flow the heat exchanger. Having previously disconnected, also flush both hoses.
- c) If it is not possible to restore the patency of the heat exchanger by flushing, the unit should be replaced.