Heating and A/C Unit
Heating and A/C Unit
Special tools, testers and auxiliary items required
• A/C service station (VAS 6007A) or succeeding model.
• Drip tray (V.A.G 1306)
• Hose clamps up to dia. 40 mm (VAS 3093)
• Compressed air gun, commercially available
Removing
• To improve accessibility, additional components e.g. engine cover must be removed (depending on engine version)
- Extract refrigerant e.g. using A/C service station (VAS 6007A), only then open the refrigerant circuit. Observe notes => [ Refrigerant Circuit ] Refrigerant Circuit.
- Remove instrument panel
- Remove rear channels for right and left footwells => [ Rear Footwell Channel ] Vents
- Place Drip tray (V.A.G 1306) under the engine.
- Mark coolant hoses - 1 -.
CAUTION!
Contact with hot engine coolant can cause severe scalding.
Coolant temperature can be above 212° F (100 °C) with a warm engine. The cooling system is under pressure.
If necessary, reduce pressure and temperature before repairs.
- Clamp off coolant hoses - 1 - using hose clamps up to dia. 40 mm (VAS 3093) and disconnect coolant hoses to heater core.
- Connect a section of hose - A - onto upper connection.
- Hold a container - B - under the lower connection - C -.
- Using a compressed air gun, carefully blow residual coolant out of heater core at heater core connection.
Only for vehicles with shielding plate in front of expansion valve
• Clamping washers are installed on right hand drive vehicles instead of a clamp and nut.
- Remove the nut - 1 - (6 ± 0.9 Nm).
- Loosen clips - 2 - and remove shielding plate - 3 -.
All vehicles
CAUTION!
There is a danger of ice-up.
Refrigerant leaks out if refrigerant circuit is not discharged.
Refrigerant must be extracted before opening refrigerant circuit. If refrigerant circuit is not opened within 10 minutes of extraction, pressure may form in refrigerant circuit due to evaporation. Extract refrigerant once more.
- Working from the engine compartment, remove the bolts (10 ± 1 Nm) - 1 - on the refrigerant lines - 2 -.
- Disconnect refrigerant lines from expansion valve - 3 -.
• Seal open pipe connections.
• To seal off all open connections on expansion valve, sealing caps from a replacement expansion valve can be used (preventing dirt and moisture from entering the system).
- Cover floor carpet in vehicle interior with leak-proof foil and absorbent paper.
• On removal, note down bolt lengths and assignment for re-installation.
1 Screw
• 4.5 ± 0.7 Nm
• on the lower right, on the air conditioner cable bracket near the bulkhead.
2 Screws
• 4.5 ± 0.7 Nm
3 Cable bracket
4 Heating and A/C unit
• Removing:
- Disconnect condensation water hose from heating and A/C unit => [ Condensation Water Drain Hose on Heating and A/C Unit, Checking ] Testing and Inspection.
- Disconnect harness connectors from heating and A/C unit.
• All cable ties and other wiring harness fasteners released or cut open on removing air conditioner unit are to be re-attached in same position on installation.
• The air conditioning wiring harness is removed with the A/C unit.
- Remove the two nuts from the comfort system central control module (J393) and secure the module to the side
- Remove the bolts - 6 - and the bracket - 5 -.
- Remove the bolts - 8 - and - 10 - and the supports - 9 - and - 11 -.
- Remove the bolts - 12 - and - 14 - and the bracket - 13 -.
- Remove the bolts - 1 - and - 2 - from the wiring bracket - 3 -.
• To be able to reach the bolt - 1 -, the air conditioner on the driver side must be pulled out slightly from the facing wall.
• When removing heat unit, make sure the two coolant pipes of the heater core do not get caught and bent or damaged on plenum chamber or noise insulation pan.
• Also pay attention to wiring harness, individual wiring connections may get damaged when pulling too forcefully on wiring harness.
- Remove heating and A/C unit.
Installing:
Installation is carried out in the reverse order, when doing this note the following:
• The assistance of a second technician is necessary to install the heating unit.
- When inserting heating unit, have the second technician guide both coolant pipes to heater core through the seal (from engine compartment)=> [ Seal for heating and A/C unit / engine compartment ].
- When installing, make sure condensation water hose is seated correctly => [ Condensation Water Drain Hose on Heating and A/C Unit, Checking ] Testing and Inspection.
- Fill with coolant
- Fill with R134a refrigerant and refrigerant oil.
5 Bracket
6 Screws
• 8 Nm
7 Assembly carrier
8 Screws
• 9 ± 1.3 Nm
9 Right support
10 Screws
• 20 ± 3 Nm
11 Left support
12 Screws
• 9 ± 1.3 Nm
13 Bracket
14 Screws
• 9 ± 1.3 Nm
• Only tighten the bolts - 8 - when installing the supports - 9 - and - 11 -.
Seal for heating and A/C unit / engine compartment
• Note installation position of seal - A - during assembly.