Receiver Dryer: Service and Repair
Reservoir
• A modified reservoir is installed in the Audi RS4. The bracket for this reservoir is not provided as a single part (only together with the reservoir).
• In the future reservoir - A - with part number " 8E0 820 193" and index "E" or "F" will not be available as a replacement part. It will be replaced by the reservoir with the same part number and index "P" and "Q". If a reservoir with a part number index starting from "P" is installed in a vehicle in which a reservoir with a part number with index " E" or "F" was previously installed, a wear protection - C - (e.g. a rubber star as a spacer) is installed on refrigerant line - B - (to protect refrigerant line - B - from wear at screw - D - or at the bracket)
Removing
- Drain refrigerant circuit.
- Completely remove the front bumper.
- Move the lock carrier to the service position (not always necessary depending on the vehicle). Refer to => Radiator Support Radiator Support
- Remove the charge air cooler or the secondary air pump motor (not always necessary, depending on the vehicle).
- Remove bolts - A - and disconnect refrigerant lines - B - and - C -.
- Remove bolts - A -.
- Remove the tab on the bracket for reservoir - B - from the body
- Remove the reservoir with the bracket.
- Loosen screws - C - and remove the reservoir from bracket - D -.
• Seal open pipe connections.
• Attachment of the refrigerant lines differs depending on the engine version.
• Keep reservoir closed as long as possible; only remove caps immediately prior to installation (reservoir contains a desiccant bag which soon becomes saturated with moisture and thus unusable when reservoir is open).
Installing
Installation is carried out in the reverse order, when doing this note the following:
Before installing the reservoir. Refer to => Heating and Air Conditioning Heating and Air Conditioning
- Check the type of seal at the connections and the refrigerant lines. These must be designed for the same type of seal. Refer to => [ Refrigerant Line to Component Connections ] Refrigerant Circuit, Servicing.
• Connection at reservoir can be marked with "IN" (from evaporator) and "OUT" (to compressor).
• The removed reservoir contains refrigerant oil that must be returned to the refrigerant circuit (with the new reservoir).
• Adjustment of the oil quantity depends on the nature of the problem. If the reservoir was damaged, e.g. during an accident (no refrigerant escaped, no moisture or dirt entered refrigerant circuit), the A/C system can be serviced without the need for extensive repair work by weighing the old and new reservoir. Pour refrigerant oil into new reservoir until it weighs the same as the reservoir removed.
• If an indeterminate amount of refrigerant oil has escaped or dirt and moisture have entered into refrigerant circuit, it must be cleaned using compressed air and nitrogen.
- Insert the reservoir in bracket - D -.
- Attach bracket - D - via tab - B -.
- Install screws - A - and tighten (tightening torque of 8 Nm).
- Replace O-ring seals - D -.
- Rotate the reservoir so that both refrigerant lines - B - and - C - can be installed in the reservoir without tension. In doing so, pay attention to correct assignment of connections.
- Attach the refrigerant line with screw - A - to the reservoir (tightening torque 10 Nm for screws with thread M6 and 25 Nm for screws with thread M8). Secure the reservoir against rotation with an oil filter band for example.
- Tighten screw - C - (tightening torque of 8 Nm).
- Check the distance of refrigerant line - B - from screw - D - and the bracket. If necessary, install wear protection - C - (e.g. a rubber star as a spacer)
• If reservoir - A - with part number "8E0 820 193 " to index "F" was replaced by a reservoir with the same part number starting from index "P". wear protection - C - (e.g. a rubber star as a spacer.) must always be installed.
- Check the routing of the refrigerant lines. They must not touch other components and must be far enough away to avoid wear. If necessary, install wear protection.
- Re-install remaining components removed.
- Evacuate and re-charge refrigerant circuit.