Refrigerant Circuit, Cleaning

Procedure 

-- Perform preliminary work for flushing the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CLEANING .

-- Check the refrigerant quantity in the A/C Service Station; there must be at least 6 kg refrigerant present. Refer to Owner's Manual.

-- Empty the used oil reservoir of the A/C Service Station. Refer to Owner's Manual.

-- Connect the supply hose (high pressure side) of A/C Service Station to the low pressure line leading to the A/C compressor (line with larger diameter) using an adapter. Refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT .

-- Connect the return hose (low pressure or intake side) of the A/C Service Station to the output of refrigerant circuit flushing device.

-- Connect the input on the flushing device to the high pressure line leading to the A/C compressor (line with smaller diameter) using an adapter. Refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT .

• Main Wiring Diagrams for Various Flushing Circuits. Refer to REFRIGERANT CIRCUIT, CLEANING .

• While flushing, contaminants from the refrigerant circuit enter the refrigerant circuit flushing device and the A/C Service Station and are absorbed by the filters and dryers installed there. Depending on the contaminant, these components are to be replaced in shorter intervals according to the Owner's Manual for the A/C Service Station or refrigerant circuit flushing device. Refer to Owner's Manual.
• If components such as, for example, an expansion valve are installed, the liquid refrigerant cannot flow through the refrigerant circuit with the required speed. This is why several components must be removed and replaced by adapters. Refer to REFRIGERANT CIRCUIT, CLEANING .

Perform flushing procedure

The process is done automatically, following the program of the A/C Service Station. Refer to Owner's Manual.

-- Select program for flushing.

-- Flushing the refrigerant circuit.

Tip

• One flushing cycle (consisting of 4 flushing procedures) has a duration of approximately 1 to 1.5 hours.
• Depending on version of the A/C Service Station, old oil container holds only approximately 125 cm ³ refrigerant oil, in the event a system with a larger quantity of refrigerant oil must be flushed, it may be necessary to drain the old oil container after the first flushing process of one flushing cycle.

-- Monitor the refrigerant which is flowing from the refrigerant circuit back into the A/C Service Station, through the looking glass of the flushing device.

• Only when the refrigerant is flowing clear and absolutely transparent into the A/C Service Station, then the refrigerant circuit is cleaned.

Tip

• All the refrigerant oil is washed out of the refrigerant circuit during flushing (except for a very small amount in the evaporator, however this can be disregarded).
• If heavily contaminated, it may be necessary to perform the flushing procedure twice (two flushing cycles with four flushing operations each).

-- After completion of the flushing procedure, check the looking glasses of the flushing device for contamination. Clean if there is contamination. Refer to Owner's Manual. Then repeat the flushing procedure to check (one procedure with a duration of 30 min. is sufficient).

-- Check pressure in refrigerant circuit. There must not be any pressure in the refrigerant circuit (evacuate the refrigerant circuit briefly once more if necessary).

-- Disconnect the A/C Service Station from the refrigerant circuit of the vehicle.

-- Depending on the design of the refrigerant circuit, some components must be replaced after flushing. Refer to REFRIGERANT CIRCUIT, CLEANING  or Refrigerant Circuit .

-- Perform an adaption of the refrigerant oil amount in the refrigerant circuit, depending on the complaint. Refer to COMPONENTS, REPLACING  and REFRIGERANT OIL CAPACITIES .

-- Charge the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CHARGING .

-- A/C System, Starting according to guidelines. Refer to A/C SYSTEM, OPERATING AFTER CHARGING .