Question 1

When a compressor needs replacing

Accepted Answer

The air conditioning compressor circulates refrigerant through the system. Its internal bearings and mechanical parts wear over time. Typical life is 150 000–250 000 km, but long periods of non-use (e.g. winter) can dry out seals and cause premature leaks.

Symptoms of a faulty compressor: AC doesn't cool, metallic noise when the compressor engages, visible oil leak under the compressor and at worst a blown electrical clutch. Diagnostics measure pressures on the suction and discharge sides — deviations quickly reveal the fault.

Question 2

How a compressor is replaced

Accepted Answer

The system's refrigerant is recovered environmentally with specialist equipment. The compressor is removed along with its belt, mounting bolts and refrigerant lines. The old compressor is replaced with a new one and the system is flushed with cleaning solution to remove old metal shavings.

The new compressor is fitted with new O-rings. The dryer is always replaced at the same time — it contains absorbent material that collects moisture and has a limited service life. The system is evacuated to vacuum, filled with the correct amount of refrigerant and taken on a test drive.

Question 3

Why do compressors fail?

Accepted Answer

The most common cause is winter non-use — seals dry out and compressor oil settles in the system. So air conditioning should be used at least once a month even in winter. Another common cause is refrigerant loss — small leaks over time empty the system, and without sufficient refrigerant the compressor runs dry and wears the bearings.

AC Compressor Repair in Vantaa