Refrigerant Lines, Disconnecting And Connecting
Special tools and workshop equipment required
- Engine Bung Set:VAS 6122
- For all the following work, close the open lines and connections with clean plugs from the Engine Bung Set:VAS 6122 .
- 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 plenum chamber 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
-- Switch off (deactivate) the "parking air conditioner". Refer to Owner's Manual.
-- Switch the ignition on.
-- Vehicles with Heat Pump Function, 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 .
-- Switch off the ignition.
Continuation for all vehicles
-- Discharge the refrigerant circuit. Refer to Refrigerant Circuit or A/C SERVICE STATION, USING .
-- To loosen the connection locations remove the front left wheel housing liner. Refer to FRONT WHEEL HOUSING LINER, REMOVING AND INSTALLING (for accessibility to the illustrated connection point).
Danger of frostbite due to refrigerant coming out under pressure.
Frostbite on the skin and other parts of the body is possible.
- Wear safety gloves.
- Wear protective eyewear.
- Evacuate or drain refrigerant and open the refrigerant circuit immediately.
- If more than 10 minutes elapse after extracting or draining the refrigerant and the refrigerant circuit has not been opened, extract or drain the refrigerant again. Pressure develops in the refrigerant circuit due to evaporation.
-- 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 or Working with A/C Service Station .
Vehicles with High-Voltage System
-- Switch the ignition on.
-- Vehicles with Heat Pump Function, Initiate the basic setting of the A/C system through the Thermal Management Control Module -J1024- and activate the power-controlled valves using the routine Charge/flush the refrigerant circuit stop routine using the Vehicle Diagnostic Tester .
Continuation for all vehicles
-- Operate 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