General Repair Instructions

WARNING: This page is about a different car, the 2002 Volvo C70, 2001 Volvo C70, 2000 Volvo C70, 1999 Volvo C70, and 1998 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Remedy, Plugs, O-Rings, Threads And Receiver Drier

Courtesy of VOLVO CARS OF NORTH AMERICA.

CAUTION: Moisture (water) in the system is the worst enemy of an air conditioning system.

Remedy immediately!

Any leakage must be remedied immediately in order to prevent moisture, air or foreign particles entering the system. In addition it is vital that working conditions are kept clean and dry.

If dirt has entered any component it must be cleaned or replaced.

In the event of collision damage, all components that may have been damaged must be checked thoroughly. Soldered joints must be checked extra carefully.

NOTE: Damaged hoses/pipes must be replaced. They must not be repaired.

Use plugs!

Protective plugs must be used as soon as a connection is separated. The plugs must be removed as late as possible (directly prior to connection).

This is especially important for the receiver drier and evaporator.

A plug kit is available as a replacement part.

The oil is hygroscopic (= moisture absorbent) and must therefore be stored in a seal container. This is especially important for PAG oil.

O-rings, threads

If a connection is taken apart the O-ring(s) must be replaced.

NOTE: Different O-rings depending on the type of refrigerant.

O-rings and threads must be lubricated with the correct type of oil prior to installation.

CAUTION: The ability of O-rings to seal is dependent on them being lubricated.

Replacing the receiver drier

If the system is opened the receiver drier must be replaced:

if air has entered the system for longer than 10 minutes.
if it is suspected that there is moisture in the system.
if the receiver drier is more than 1 year old.

The receiver drier should usually be replaced on most of the occasions that the system is opened.

This is because the drying agent is not reversible. It is not possible to extract water from the drying agent by vacuum pumping the system.

Topping up oil

Too much oil reduces cooling capacity.

Too little oil will damage the compressor.

The oil must be topped up when repairing a leak or when replacing a component.

The amount of oil required depends on the extent of the leak, whether it was large or small and on which components are replaced.

There are different oils depending on the type of refrigerant and compressor.

Some of the effects of too much water in the system

Internal corrosion ("rust")

Corrosive damage, applies in particular to systems with R12.

At high temperatures water functions as a catalyst for the break down of R12. Chlorine in R12 then compounds with the water and forms hydrochloric acid (=corrosive damage).

Poor power, interrupted operation (the compressor is disengaged for long periods).

The water freezes to ice at low temperatures and blocks the system, for example in the expansion pipe. As a result the pressure in the high pressure section increases and the safety switch disengages the compressor. It is then disengaged until the ice melts and the pressure has dropped.

Damage to the compressor (breakdown, reduced service life).

Liquids cannot be compressed so drops of water increase the load on the compressor.

Difficulties extracting the water from the system when vacuum pumping.

When the pressure sinks the water evaporates. Because pipes and hoses are poor conductors of heat, the heat (energy) required for evaporation is obtained from the water. As a result the water is over cooled and freezes to ice, blocking the system.