Refrigerant
The characteristics of the refrigerant are indicated on the label located in the engine compartment of the car.
Use the high pressure line of the filling station to collect, create a vacuum and charge the R134A refrigerant.
Note. Be sure to plug the air conditioning piping openings with plugs to prevent moisture from entering the system. Remove plugs from spare parts only at the last moment before installing them.
Note. With the engine running, check for leaks with a leak detector five minutes after refueling; at the same time, the heater and the air blower must operate at maximum mode.
Note. Follow all instructions for topping up oil when working on air conditioning system components.
Note. When replacing valves, observe the required tightening torque of 8 Nm.
Pic. 8.135. Refrigerant charge
Air conditioning system maintenance
Every year of operation it is recommended:
- clean and purge the condenser and radiator of the engine cooling system;
- make sure that the condensate drain hole in the cold air blower is not clogged.
It is recommended to check the refrigerant charge of the refrigeration circuit or drain the refrigerant every four years.
Bactericidal preparation for the treatment of the air conditioning system
Note. Treat the heating and ventilation system with a special preparation after each winter season or a long break in the operation of the system in order to eliminate possible contamination.
Note. Spray all of the preparation from the aerosol can with extension through the filter port of the cabin ventilation system.
Attention! It is strictly forbidden to spray the product through the air intake inlet and because of the risk of damage to the electric air blower.
Attention! Wait 15 min.
Attention! Turn on the fan at very low speed for 5 minutes.
Draining the refrigerant
Note. Since the air conditioning circuit is equipped with only one filling valve, some filling stations use only the high pressure pipe.
Note. In some cases, let the system run for a few minutes before draining the refrigerant to ensure complete draining.
When draining the refrigerant or when checking the charge of the refrigeration circuit, three cases must be taken into account:
- 1. Engine and air conditioning are running;
- 2. The engine runs, but the air conditioner does not work;
- 3. The engine and air conditioner do not work.
Engine and A/C running
Let the air conditioner run until the engine cooling fan turns on twice, then stop the engine.
Carry out the first refrigerant drain (measure its amount), wait 15 min.
Check that the relative pressure is less than or equal to 0 bar, restart the drain cycles if the pressure is not less than or equal to 0 bar.
Sum the amount of refrigerant drained from all cycles.
Charging is considered sufficient if the amount received is +35 gr or -100 gr from the nominal value.
Engine runs but air conditioner does not work
Let the engine run until the cooling fan turns on twice, then stop the engine.
Carry out the first refrigerant drain (measure its amount), wait 15 min.
Let the engine run until the electric fan of the cooling system turns on twice, drain the coolant a second time (measure its amount).
Restart drain cycles if pressure is not less than or equal to 0 bar.
Sum the quantities of refrigerant drained from all cycles.
Charging is considered sufficient if the amount received is +35 gr or -100 gr from the nominal value.
Engine and air conditioner not working
Carry out the first refrigerant drain (3. The engine and air conditioner do not work.), wait 2 hours.
Restart drain cycles if pressure is not less than or equal to 0 bar.
Sum the quantities of refrigerant drained from all cycles.
Charging is considered sufficient if the amount received is +35 gr or -100 gr from the nominal value.
Pic. 8.136. Operation of the air conditioning system: 1 - compressor; 2 - condenser; 3 - receiver-drier; 4 - pressure sensor; 5 - reducer with a tubular control valve; 6 - evaporator; 7 - interior electric fan; 8 - electric fan of the engine cooling system; 9 - radiator of the engine cooling system; 10 - refrigerant under high pressure; 11 – steam under low pressure; 12 - steam under high pressure; 13 - filling valve; 14 - salon; 15 - engine compartment; 16 - outside air; 17 - to the air distribution unit; 18 – bulkhead shield; 19 - outside or recirculated air; 20 - pipeline flange on the bulkhead
Air extraction
Be sure to properly evacuate the air from the refrigeration circuit before charging it with refrigerant, otherwise the air conditioner will fail.
There are two cases to consider:
- air is pumped out immediately after the circuit is discharged;
- air is evacuated a few hours or days after the discharge of the circuit.
Air is evacuated immediately after the circuit is discharged.
Air is pumped out for 20 minutes.
Air is evacuated a few hours or days after the discharge of the circuit.
Air is pumped out for 45 minutes to completely eliminate traces of moisture.
After evacuating the air, check the circuit for leaks (some charging stations do this automatically).
Refrigerant charge
Add oil of the right brand and in the right amount, depending on the work performed.
Refuel.
Empty the filling station pipes.
Check system performance. Search for leaks.
Search for leaks
Pic. 8.137. Refrigerant Leak Finder Tool: 1 - capsule; 2 - ultraviolet lamp
Contrast agent supplied in single-use capsules is used to locate leaks, traces of leaks are detected using an ultraviolet lamp (pic. 8.137).
The contrast agent remains in the air conditioning system.
Using an ultraviolet lamp, you can check the condition of the refrigeration circuit.
Attention! In the presence of characteristic fluorescent traces, it is forbidden to introduce a contrast agent into the refrigeration circuit.
Attention! Administer a dose of contrast agent if there are no characteristic fluorescent traces and no warning label (about the use of a contrast agent in the past).
The introduction of a contrast agent into the circuit.
Install the contrast agent injection system on the low pressure valve 3a on vehicles with a single valve.
Inject the contrast medium into the circuit.
Turn on the air conditioner and let it run for about 15 minutes.
Leak detection procedure.
Do a pre-check (with the engine off), by passing a beam of ultraviolet lamp along the refrigeration circuit.
If no leaks are found:
- thoroughly clean the outer surfaces of the refrigeration circuit parts,
- turn on the air conditioning compressor and do not turn it off until the location of the refrigerant leak is determined (if unsuccessful, check the condition of the evaporator).
Attention! After using a contrast agent, be sure to indicate on the warning label (supplied with the capsule of this substance) the fact of its use and the date of the operation. The label must be affixed in a visible place near the filling valves of the refrigeration circuit (on the support cup of the shock absorber).
Table 8.3. Locating refrigerant leaks
Place of application | Detection zone |
Condenser | At the entrance and exit |
Evaporator | Connecting flange |
Compressor | At the entrance and exit |
Receiver dryer | At the entrance and exit |