Accumulator HVAC: Service and Repair

Accumulator, Removing And Installing

NOTE: On the Audi RS4, a modified accumulator is installed; for this accumulator, the bracket cannot be obtained separately as a replacement part (only together with the accumulator).

Removing
- Discharge refrigerant circuit
- Remove entire front bumper
- Move lock carrier to service position
- If applicable, remove charge air cooler/secondary air pump motor (not always necessary, depends on vehicle).







- Remove bolts - A - and remove refrigerant lines - B - and - C -.







- Remove bolts - A -.
- Remove lug at bracket for accumulator - B - from body.
- Remove accumulator with bracket.
- Loosen bolt - C - and pull accumulator out of bracket - D -.

NOTE:
- Seal open line connections. Connection of refrigerant lines differs depending on engine version.
- Keep accumulator closed as long as possible.
- Only remove caps immediately prior to installation (accumulator contains a desiccant bag which soon becomes saturated with moisture and hence unusable after opening accumulator).

Installing
Install in reverse order, paying attention to the following:
Before installing accumulator
- Check type of seal at connections and refrigerant lines (must be designed for same type of seal) and.

NOTE:
- Connections at accumulator may be marked "IN" (from evaporator) and "Out" (to compressor).
- The accumulator removed contains refrigerant oil, which must be returned to refrigerant circuit (together with new accumulator).
- Adjustment of the oil quantity depends on the nature of the complaint. If, for example, a accumulator has been damaged in an accident (no loss of refrigerant, no ingress of moisture and dirt into refrigerant circuit), the air conditioner can be serviced by weighing the old and new accumulator without the need for extensive repair work. Pour refrigerant oil into the new accumulator until it weighs the same as the removed.
- If an indeterminate amount of refrigerant oil has escaped or dirt and moisture have entered into the refrigerant circuit, it must be cleaned using compressed air and nitrogen.







- Insert in bracket - D -.
- Engage bracket - D - with lug - B -.
- Insert and tighten bolts - A - (tightening torque 8 Nm).







- Replace O-rings - D - .
- Turn the accumulator such that the two refrigerant lines - B - and - C - can be inserted without strain in the accumulator. In doing so, pay attention to correct assignment of connections.
- Use bolt - A - to attach refrigerant line to accumulator (tightening torque 25 Nm). Use oil filter strap for example to secure accumulator to prevent it turning.
- Tighten bolt - C - (tightening torque 8 Nm).
- Reinstall remaining components removed.
- Discharge and recharge refrigerant circuit.