Refrigerant Lines, Disconnecting And Connecting

• For all the following work, close the open lines and connections with clean plugs from the Engine Bung Set: VAS6122  .

• The procedure for loosening applies to all connection points in the refrigerant circuit and for the branching point of refrigerant lines to rear heater and A/C unit. There are differences in the line connection diameter, O-ring versions and bolts.
• Depending on component location, various components in vicinity of connection points must be loosened or removed to be able to disconnect the connection point.
• The following illustration shows as an example the connection points between the refrigerant lines from the inner heat exchanger to the A/C compressor and to the condenser as well as the connection points on the opening in the perform to the refrigerant lines to the evaporator in the rear heater and A/C unit. These connection points are installed in the area under the left front fender.

Loosening 

Vehicles with high-voltage system (Audi Q7 e-tron) 

-- Switch off (deactivate) the "parking air conditioner". Refer to Owner's Manual.

-- Initiate the A/C system basic setting through the Thermal Management Control Module -J1024- and open the power-activated valves through the stored routine "Extract, evacuate and fill the refrigerant circuit" using the Vehicle Diagnostic Tester in the "Guided Fault Finding"  function.

Continuation for All Vehicles

Courtesy of AUDI OF AMERICA, LLC

-- Switch off the ignition.

-- Discharge the refrigerant circuit. Refer to Refrigerant Circuit (R134a) or Working with A/C Service Station (R1234ya) (1 of 2) or Working with A/C Service Station (R1234yf) (2 of 2) .

-- To loosen the connection locations remove the front left wheel housing liner. Refer to OVERVIEW - FRONT WHEEL HOUSING LINER (for accessibility to the illustrated connection point).

-- Remove the bolt -A-.

-- Disconnect the connection point of the refrigerant lines -B-, -E- and -C-.

Assembling 

Assemble in the reverse order of removal. Note the following:

-- Replace the O-ring seals -D- and -G-. Refer to REFRIGERANT CIRCUIT SEALS and the Parts Information for the different versions.

-- Thoroughly clean the refrigerant lines around the connection area and check for damage.

-- If equipped, inspect the alignment pin -F- (not present on all connections) for damage and make sure that it is seated correctly.

-- Check the routing of the refrigerant lines after attachment. They must be inserted in the provided brackets in a tension-free manner and must not come in contact with other components.

-- Reinstall the removed components in the reverse order and reattach detached components.

-- Evacuate and charge the refrigerant circuit. Refer to Refrigerant Circuit (R134a) or Working with A/C Service Station (R1234ya) (1 of 2) or Working with A/C Service Station (R1234yf) (2 of 2) .

-- Switch the ignition on.

-- On vehicles with a high-voltage system (Audi Q7 e-tron), initiate the basic setting of the A/C system through the Thermal Management Control Module -J1024- and activate the power-controlled valves using one of the routines stored there. "Charge/flush the refrigerant circuit stop routine" using the Vehicle Diagnostic Tester in the "Guided Fault Finding"  function.

-- Check the DTC memory for the Front A/C Display Control Head -E87- and, if necessary, delete any displayed errors using the Vehicle Diagnostic Tester in the "Guided Fault Finding"  function.

-- Start the A/C system after charging the refrigerant circuit. Refer to A/C SYSTEM, STARTING AFTER CHARGING REFRIGERANT CIRCUIT .

Tightening Specifications 

• Refer to OVERVIEW - REFRIGERANT LINES