Refrigerant Circuit, Cleaning

Components are almost always flushed in the opposite direction of refrigerant flow when the A/C system is in operation. (Exception: the electrically-driven A/C compressor). 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 operating instructions for the A/C service station or refrigerant circuit flushing device. Refer to A/C service station Owner's Manual.

The filter in the refrigerant circuit flushing device depends on the type and degree of contamination in the flushed refrigerant circuit, it should be changed after five to ten flushing cycles (flushed vehicles) at the latest. If a heavily contaminated refrigerant circuit is flushed (the refrigerant oil from the circuit is black and viscous or there are many shavings in the refrigerant circuit), the filter should be replaced after flushing. With a refrigerant circuit heavily contaminated in this way, it is wise to flush the circuit again after changing the filter.

Depending on the type of contamination, dirt (old refrigerant oil and abraded material from A/C compressor) is deposited on the viewing glass. If necessary clean the level indicator after flushing and flush the refrigerant circuit with a flushing procedure to check (one cycle is sufficient).

Liquid refrigerant cannot be led through the expansion valve, restrictor and desiccant bag of certain receiver/dryers at the necessary speed, therefore these components must be removed and replaced by adapters if necessary. Refer to REFRIGERANT CIRCUIT, CLEANING and Refrigerant Circuit .

Adapters for connecting the A/C service station and for bridging certain refrigerant circuit components. Refer to ADAPTER FOR ASSEMBLING FLUSHING CIRCUIT .

Flushing procedure sequence. Refer to REFRIGERANT CIRCUIT, CLEANING PROCESS .

The flushing procedure is to be performed according to the A/C service station Owner's Manual. Refer to the A/C service station Owner's Manual.

Depending on version of 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.

Observe the refrigerant which flows back into the A/C service station from the refrigerant circuit, only when the refrigerant streams clear and completely colorless through the viewing glass of refrigerant circuit flushing device into the A/C service station is the refrigerant circuit cleaned.

While flushing, all the refrigerant oil is washed out of the refrigerant circuit (up to a very small amount for example 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).

There is a defined and prescribed amount of refrigerant oil in the replacement compressor. On vehicles with two evaporators if necessary install an additional certain amount of refrigerant oil in the circuit. Refer to APPROVED REFRIGERANT OILS AND REFRIGERANT OIL CAPACITIES .

If the A/C compressor is not be replaced, replace the refrigerant oil quantity in the A/C compressor to the specified capacity (pour out or flush out the refrigerant oil and refill the prescribed quantity into the A/C compressor or refrigerant circuit). Refer to COMPONENTS, REPLACING and APPROVED REFRIGERANT OILS AND REFRIGERANT OIL CAPACITIES .