audi Workshop Repair Guides

Audi Workshop Service and Repair Manuals

ABOUT US
Flushing electrically driven air conditioner compressor (removing refrigerant oil) > < Flushing (cleaning) refrigerant circuit with refrigerant R134a

A4 Mk1

Block diagrams for various flushing circuits
Block diagrams for various flushing circuits
  Note
t  The arrows in the following illustrations indicate the direction of refrigerant flow on flushing (during flushing, the refrigerant flows in the direction opposite to that in air conditioner operation; the high-pressure end of the air conditioner service station is thus connected to the low-pressure connection of the refrigerant circuit to the air conditioner compressor).
t  The block diagrams illustrate a refrigerant circuit with restrictor and reservoir and a refrigerant circuit with expansion valve, receiver and a second evaporator (optional extra for certain vehicles).
t  Depending on the design of the air conditioner service station, non-return valves may be fitted between the refrigerant circuit and the air conditioner service station (to guarantee the correct direction of refrigerant flow on flushing).
Refrigerant circuit with restrictor and reservoir
  Note
On vehicles with a restrictor and reservoir, the restrictor and reservoir are removed and the lines unfastened to remove the restrictor are connected back together. The line connections to the reservoir removed are connected together with two adapters and the charging hose -VAS 6338/31- (from the VW/Audi passenger vehicle adapter set -VAS 6338/1-).
   
1 - Air conditioner service station
q   With electronics and a flushing program, e.g. Air conditioner service station with flushing attachment → Workshop equipment and special tools catalogue
q   If use is made of an air conditioner service station with no flushing program, the process is to be implemented manually (evacuation, 3x flushing with at least 4 kg of refrigerant each time, extraction of refrigerant again, evacuation).
2 - Refrigerant hose of air conditioner service station
q   From the high-pressure end of the air conditioner service station (generally red coloured) to the connection for the low-pressure end of the air conditioner compressor at the refrigerant circuit (larger diameter)
3 - Adapter for connection (low-pressure side) at refrigerant circuit
q   Different versions depending on vehicle → Chapter
q   From adapter set for refrigerant circuits -VAS 6338/1-
4 - Connection (low-pressure side) at refrigerant circuit
q   Different versions depending on vehicle → Chapter
q   At the refrigerant pipe from the air conditioner compressor to the reservoir
5 - Connection to reservoir
q   Different versions depending on vehicle → Chapter
q   At the refrigerant pipe from the air conditioner compressor to the reservoir
6 - Adapter for bridging reservoir after removal
q   Different versions depending on vehicle → Chapter
q   From adapter set for refrigerant circuits -VAS 6338/1-
7 - Filler hose for refrigerant → Chapter
q   For example filler hose -VAS 6338/31- (from adapter set for refrigerant circuits -VAS 6338/1-)
8 - Adapter for bridging reservoir after removal
q   Different versions depending on vehicle → Chapter
q   From adapter set for refrigerant circuits -VAS 6338/1-
9 - Connection to reservoir
q   Different versions depending on vehicle → Chapter
10 - Evaporator
11 - Fitting location for restrictor
q   Restrictor removed.
q   Remove the restrictor → Heating, air conditioning; Rep. gr.87 or → Air conditioning; Rep. gr.87 (vehicle-specific workshop manual).
12 - Bolt connection in refrigerant line
q   Screw back together following restrictor removal → Heating, air conditioning; Rep. gr.87 or → Air conditioning; Rep. gr.87 (vehicle-specific workshop manual).
13 - Condenser
14 - Connection (high-pressure side) at refrigerant circuit
q   Different versions depending on vehicle → Chapter
15 - Adapter for connection (high-pressure side) at refrigerant circuit
q   Different versions depending on vehicle → Chapter
q   From adapter set for refrigerant circuits -VAS 6338/1-
16 - Filler hose to flushing kit for refrigerant circuits
q   From the high-pressure end connection of the air conditioner compressor at the refrigerant circuit (smaller diameter) to the inlet of the refrigerant circuit flushing attachment.
17 - Flushing kit for refrigerant circuits
q   Different versions and different design of flushing kit for refrigerant circuits → Workshop equipment and special tools catalogue
q   With filter, sight glass, safety valve, heater, refrigerant vessel etc. (depending on version)
q   Depending on the design of the air conditioner service station and the refrigerant circuit flushing kit, a non-return valve may be fitted at the outlet of the refrigerant circuit flushing kit (to guarantee the correct direction of refrigerant flow when flushing).
18 - Refrigerant hose of air conditioner service station
q   From low-pressure side of air conditioner service station (usually blue) to outlet of flushing kit for refrigerant circuits

Refrigerant circuit with expansion valve, receiver and second evaporator
  Note
t  This block diagram shows a refrigerant circuit with expansion valve, receiver and a second evaporator (optional extra for certain vehicles).
t  On vehicles with expansion valve and receiver, the expansion valve is removed and replaced with an adapter. Depending on the vehicle, the receiver is also removed and the pipe connections to the receiver are connected using two adapters and a filler hose.
t  On vehicles with only one evaporator, the components from item „16“ onwards are not fitted / are not required.
   
1 - Air conditioner service station
q   With electronics and flushing program, Air conditioner service station with flushing kit → Workshop equipment and special tools catalogue
q   If use is made of an air conditioner service station with no flushing program, the process is to be implemented manually (evacuation, 3x flushing with at least 4 kg of refrigerant each time, extraction of refrigerant again, evacuation).
2 - Refrigerant hose of air conditioner service station
q   From the high-pressure end of the air conditioner service station (generally red coloured) to the connection for the low-pressure end of the air conditioner compressor at the refrigerant circuit (larger diameter)
3 - Adapter for connection (low-pressure side) at refrigerant circuit
q   Different versions depending on vehicle → Chapter
q   From adapter set for refrigerant circuits -VAS 6338/1-
4 - Connection (low-pressure side) at refrigerant circuit
q   Different versions depending on vehicle → Chapter
5 - Adapter for removed expansion valve
q   Different versions depending on vehicle → Chapter
q   From adapter set for refrigerant circuits -VAS 6338/1-
6 - Evaporator
7 - Connection to receiver
q   Different versions depending on vehicle → Chapter
q   Not fitted on vehicles with a dryer cartridge in the receiver at the condenser or with a receiver installed in the condenser → Heating, air conditioning; Rep. gr.87 or → Air conditioning; Rep. gr.87 (vehicle-specific workshop manual).
8 - Adapter for bridging removed receiver
q   Not necessary on all vehicles
q   Different versions depending on vehicle → Chapter
q   From adapter set for refrigerant circuits -VAS 6338/1-
9 - Filler hose for refrigerant → Chapter
q   For example filler hose -VAS 6338/31- (from adapter set for refrigerant circuits -VAS 6338/1-)
10 - Condenser
q   If a receiver with dryer cartridge is fitted at the condenser, the dryer cartridge must be removed (seal receiver at or in condenser again following removal) → Heating, air conditioning; Rep. gr.87 or → Air conditioning; Rep. gr.87 vehicle-specific workshop manual).
q   If the receiver is attached directly to the condenser, the receiver is only to be removed and renewed after flushing → Heating, air conditioning; Rep. gr.87 or → Air conditioning; Rep. gr.87 (vehicle-specific workshop manual).
  Note
On certain vehicles, the receiver is integrated into the condenser and the dryer cartridge cannot be renewed separately or is not available separately. On these vehicles, the condenser is then to be renewed together with the receiver / dryer cartridge after flushing → Heating, air conditioning; Rep. gr.87 and → Electronic parts catalogue.
11 - Connection (high-pressure side) at refrigerant circuit
q   Different versions depending on vehicle → Chapter
12 - Adapter for connection (high-pressure side) at refrigerant circuit
q   Different versions depending on vehicle → Chapter
q   From adapter set for refrigerant circuits -VAS 6338/1-
13 - Filler hose to flushing kit for refrigerant circuits
q   From the high-pressure end connection of the air conditioner compressor at the refrigerant circuit (smaller diameter) to the inlet of the refrigerant circuit flushing attachment.
14 - Flushing kit for refrigerant circuits
q   Different versions and different design of flushing kit for refrigerant circuits → Workshop equipment and special tools catalogue
q   With filter, sight glass, safety valve, heater, refrigerant vessel etc. (depending on version)
q   Depending on the design of the air conditioner service station and the refrigerant circuit flushing kit, a non-return valve may be fitted at the outlet of the refrigerant circuit flushing kit (to guarantee the correct direction of refrigerant flow when flushing).
15 - Refrigerant hose of air conditioner service station
q   From low-pressure side of air conditioner service station (usually blue) to outlet of flushing kit for refrigerant circuits
16 - Adapter for sealing outlet to second evaporator
q   Only required for certain vehicles with „second evaporator“ as optional extra
q   From adapter set for refrigerant circuits -VAS 6338/1-
17 - Adapter for sealing outlet to second evaporator
q   Only required for certain vehicles with „second evaporator“ as optional extra
q   From adapter set for refrigerant circuits -VAS 6338/1-
18 - Connection (low-pressure side) at refrigerant circuit to second evaporator
q   Different versions depending on vehicle → Chapter
q   Only fitted on certain vehicles with „second evaporator“ as optional extra
19 - Connection (high-pressure side) at refrigerant circuit to second evaporator
q   Different versions depending on vehicle → Chapter
q   Only fitted on certain vehicles with „second evaporator“ as optional extra
20 - Adapter for expansion valve (removed) at second evaporator
q   Different versions depending on vehicle → Chapter
q   Only required for certain vehicles with „second evaporator“ as optional extra
q   From adapter set for refrigerant circuits -VAS 6338/1-
21 - Second evaporator
q   Only fitted on certain vehicles with „second evaporator“ as optional extra

   

Flushing electrically driven air conditioner compressor (removing refrigerant oil) > < Flushing (cleaning) refrigerant circuit with refrigerant R134a