64 53... Instructions for desiccant insert replacement

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

However, the drier bottle or drier insert must be replaced without fail in the event of: 

• Contamination of the refrigerant with dirt/debris (e.g. when the compressor is clamped).
• With depressurized and/or completely drained refrigerant circuit.
• With a refrigerant circuit, which was closed using special tool 32 1 270 but remains open for more than 24 hours.