Quick check of serviceability of functioning of the air conditioning system (on the example of a 901 series minibus, - for M-class models, the check is carried out in a similar manner)
1 - Temperature meter; 2 - Viewing window of the receiver-drier; 3 - Refrigerant leak detector
1. Illustrative material for a quick check of the functioning of the air conditioning system is presented in the illustration, which includes all references in the text.
2. Drive the car into the shade, open all windows.
3. Move the temperature selection knob to the COLD position (Cold).
4. Turn on fresh air mode.
5. Fully open the nozzle passages of all air ducts.
6. Run the engine to idle.
7. Turn on K / V, - the engine speed should increase.
8. Turn on the maximum fan speed.
9. Through the viewing window of the receiver-drier (2) check for signs of refrigerant bubbles.
Note. When starting a freshly charged system for the first time, the formation of air bubbles should not be a cause for concern - wait about 10 minutes - the bubbles should disappear.
10. Carefully examine the external condition of all components of the refrigeration A/C, using a special detector, check them for signs of leak development.
11. Set the fan to high speed «1» and with a special meter (1) measure the temperature of the air escaping through the central deflectors of the instrument panel. After 5 minutes of system operation, the temperature of the air supplied to the passenger compartment must be within the range of +2°С ÷ +12°С, and the A/C compressor must switch to cyclic mode (on off), otherwise check the condition of the evaporator temperature switch.
12. Turn off the air conditioner and turn off the engine - more detailed checks of the A/C system should be carried out in a car service workshop.