BMW 7 Series: Instructions For Desiccant Insert Replacement

A desiccant insert that is in a correctly functioning, sealed A/C system does not have to be changed at regular service-inspection intervals.

The desiccant bottle or desiccant insert must be replaced in the event of

• the refrigerant being fouled by chips (e.g. mechanical damage to the compressor due to clamping)
• a leaking A/C system or loss of refrigerant
• the refrigerant circuit being open for a period exceeding 24 hours (e.g. during a repair)

INSTRUCTIONS FOR OPENING AND REPLACING PARTS IN REFRIGERANT CIRCUIT

WARNING:

• Avoid contact with refrigerant and refrigerant fluid.
• Follow safety instructions for handling R 134A refrigerant.
• Follow safety information for HANDLING REFRIGERANT FLUID.

IMPORTANT:

• Always use new O-rings each time A/C connections are opened (refer to Electronic Parts Catalogue) They must not be coated.

  Use special tool 00 9 030 to install sealing rings without damaging them.

• Open the refrigerant circuit for as short of a period as possible.
• Close all components and lines in the refrigerant circuit and return parts immediately following the removals at openings with special tool 32 1 270 to prevent penetration of moisture or foreign objects.
• If the refrigerant circuit was closed at the openings with special tool 32 1 270 but it remains open for more than 24 hours, the dryer insert for the air conditioning must be replaced.

I. Part replacement as preliminary work fur further repair work and part replacement based on gradual leakage

(minor leak, e.g. hairline crack)

Procedure:

• DRAW OFF A/C system, then determine drawn-off refrigerant oil quantity
• Carry out part replacement
• Replace removed refrigerant fluid and additionally top up with new refrigerant fluid according to components replaced:
  • Compressor: refer to NOTES ON REPLACING COMPRESSOR
  • Evaporator: 10 ml
  • Capacitor: 20 ml
  • Desiccant insert/dryer flask: 20 ml
  • Each replaced refrigerant line: 10 ml
  • Capacitor with integrated dryer: 40 ml
  • Safety pressure switch and seals: no additional refrigerant fluid
• EVACUATE AND FILL A/C system

II. Part replacement due to sudden leak

(major leak, e.g. pipe break due to accident)

Procedure:

• DRAW OFF A/C system, then determine drawn-off refrigerant oil quantity
• Carry out part replacement
• Replace removed refrigerant fluid and additionally top up with new refrigerant fluid according to components replaced:
  • Compressor: refer to NOTES ON REPLACING COMPRESSOR
  • Evaporator: 35 ml
  • Capacitor: 35 ml
  • Desiccant insert/dryer flask: 55 ml
  • Each replaced refrigerant line: 35 ml
  • Capacitor with integrated dryer: 55 ml
  • Safety pressure switch and seals: no additional refrigerant fluid
• EVACUATE AND FILL A/C system

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