Removal and Replacement
Heater and A/C Unit
Special tools, testers and auxiliary items required
• ROB 134APF or succeeding model.
• Drip Tray For Workshop Hoist (VAS6208)
• Hose Clamps up to 40 mm (3093)
• Compressed air gun, commercially available
Removing
• To improve accessibility, additional components must be removed, for example, the engine cover (depending on engine version).
- Extract refrigerant using ROB 134APF , only then open the refrigerant circuit. See notes, refer to => [ Refrigerant Circuit System Overview ] Refrigerant Circuit System Overview.
- Remove the instrument panel.
- Place (VAS 6208) under the engine.
- Mark the coolant hoses - 1 -.
Contact with hot engine coolant can cause severe scalding.
Coolant temperature can be above 100 °C (212 °F) with a warm engine. The coolant system is under pressure.
If necessary, reduce pressure and temperature before repairs.
- Clamp the coolant hoses - 1 - using the (3093) and remove the coolant hoses from the heater core.
- Connect a section of hose - A - to the 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 a heat shield in front of the expansion valve
- Remove the nut - 1 - (6 +/- 0.9 Nm).
- Remove the clamps - 2 - and the heat shield - 3 -.
All vehicles
Danger due to refrigerant coming out under pressure.
Danger of frost bite to skin and other parts of the body.
• Extract the refrigerant and immediately open the refrigerant circuit after that.
• If the refrigerant was extracted more than 10 minutes in the past and the refrigerant circuit was not opened, extract the refrigerant again. Pressure in the refrigerant circuit is caused by evaporation.
- From inside the engine compartment, remove the bolts (10 +/- 1 Nm), - 2 - from the refrigerant pipes - 2 -.
- Remove the refrigerant pipes from the expansion valve - 3 -.
• Seal the open 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 the carpet inside the passenger compartment with waterproof foil and water absorbing paper.
When removing the bolts, make note of the lengths and allocation.
1 Screw
• 4.5 +/- 0.7 Nm
• On the lower right side on the cable bracket for the heater and air conditioner near the plenum chamber bulkhead
2 Screws
• 4.5 +/- 0.7 Nm
3 Cable Bracket
4 Heating and A/C unit
• Removing
5 Bracket
6 Screws
• 8 +/- 1 Nm
7 Subframe
• There are 2 versions of subframe - 7 -. On the version made of steel, the supports are welded to the subframe - 8 - and - 10 -. On the version made of aluminum, the supports are attached to the subframe - 8 - and - 10 - with bolts.
• The illustration shows the version made of steel.
8 Right Support
9 Screws
• 20 +/- 3 Nm
10 Left Support
11 Screws
• 9 +/- 1.3 Nm
12 Bracket
13 Screws
• 9 +/- 1.3 Nm
- Remove the condensation water hose from the heater and air conditioner. Refer to => [ Condensation Water Hose, Checking ] Testing and Inspection.
- Disconnect the connectors from the heater and air conditioner.
• All cable ties opened or cut during the removal of the A/C system must be reinstalled at the same locations during installation.
• The air conditioning wiring harness is removed with the heater and air conditioner.
- Remove the bolts - 6 - and the holder - 5 -.
- Remove screws - 9 -.
- Remove the bolts - 11 - and - 13 - and bracket - 12 -.
- Remove the subframe- 7 -..
• On the version made out of aluminum, only the supports - 8 - and - 10 - need to be removed. Tightening specification for the upper bolts on the support: 9 +/- 1.3 Nm.
- Remove the bolts - 1 - and - 2 - from the cable bracket - 3 -.
To be able to reach the bolt - 1 -, the heating and A/C unit on the driver side must be pulled out slightly from the bulkhead.
• When removing the heater and A/C unit, make sure the two coolant pipes on the heater core do not get caught and bent or damaged on plenum chamber or noise insulation pan.
• Pay attention to the wiring harness. The individual wire connections could get damaged when pulling on harness.
- Remove heating and A/C unit.
Installing
Installation is carried out in the reverse order while noting the following:
• The assistance of a second technician is necessary to install the heating and A/C unit.
- Guide both heater core coolant pipes (from inside the engine compartment) through the seals with the help of a second technician when installing the heater and A/C unit. Refer to => [ Seal heater and air conditioner / engine
compartment ]
- Make sure the condensation water hose fits correctly. Refer to => [ Condensation Water Hose, Checking ] Testing and Inspection.
- Add coolant.
- Fill with R134a refrigerant and refrigerant oil.
Seal heater and air conditioner / engine compartment
Make sure the seal - A - is installed correctly.