Checking the refrigerant level in the working path of the A/C system (Mercedes-Benz G-Class W463)

Caution! Observe all necessary precautions related to servicing the A/C systems (see Section General information and safety precautions)!

1. If the A/C receiver-dryer is placed in front of the radiator, remove the front decorative grille (see Chapter Body).

2. Wipe the viewing window glass (arrow) on the receiver-dryer assembly.

3. Disconnect the connector (2) of the low-pressure sensor-switch and short-circuit the terminals of the latter.

(Original published on the website: MercedesMan)

4. Start the engine at idle speed.

5. Turn on the heater fan and activate the air conditioning system in maximum cooling capacity mode.

6. Remove the jumper from the pressure switch connector and, looking into the viewing window of the receiver-dryer, make sure that there are no signs of refrigerant bubbling (during the initial start-up of a freshly filled system, the formation of air bubbles should not cause concern - wait about 10 minutes - the bubbles should disappear, minor bubbling is also acceptable at high [>35°C] ambient temperatures)

Note: When the compressor electromagnetic clutch is activated, the fluid flow rate should increase.

7. Carefully examine the external condition of all components of the refrigeration system, using a special detector, check them for signs of developing leaks.

8. Set the fan to speed mode "1" and measure the temperature of the air coming out through the central deflectors of the instrument panel using a special meter. After 5 minutes of system operation, the temperature of the air supplied to the cabin should be within the range of +2°C÷+12°C, and the A/C compressor should switch to cyclic mode (on-off), otherwise, check the condition of the evaporator temperature switch sensor.

9. Turn off the air conditioner and stop the engine - more detailed checks of the air conditioning system should be carried out in a car service workshop.