What is the problem when the car air conditioning compressor pressure is insufficient?
2 Answers
Possible causes of insufficient pressure in car air conditioning compressor are as follows: 1. Insufficient pressure: If the air output of the compressor cannot meet the flow requirements at rated pressure, the exhaust pressure will decrease. The observable phenomenon is that the air conditioner installed in bedrooms or living rooms stops working. In this case, replacing with a machine that has the same exhaust pressure but larger capacity is necessary to ensure normal operation. 2. Overheating components: Issues with various components of the compressor may also occur. Friction areas such as crankshaft and bearings, crosshead and slide plate, packing and piston rod may exceed prescribed temperature limits during operation. This not only accelerates component wear but may also cause serious accidents due to heat accumulation burning friction surfaces. 3. Insufficient exhaust volume: There are numerous causes for this problem, mainly including: heavily clogged intake air filters blocking exhaust passages, wear-induced exhaust obstruction, severe wear of cylinder/piston/piston rings increasing gaps between components leading to abnormal exhaust volume, substandard packing quality or misalignment between piston rod and packing center during installation causing air leakage, mismatch between valve spring force and gas force - insufficient tightening force causes leakage while excessive force deforms/damages valve covers. Any valve malfunction will affect both gas volume and pressure regulation.
I've been repairing cars for over 30 years and have seen countless cases of insufficient air conditioning compressor pressure. The most common issue is insufficient refrigerant, often due to leaks in the system—whether it's aging seal rings at the connections or pinholes in the condenser causing refrigerant loss. Compressor failures are also frequent, with problems like piston wear or valve seal leaks leading to internal leakage and reduced compression efficiency. Stuck expansion valves are particularly troublesome—either opening too little and blocking refrigerant flow or failing to close properly, causing system pressure imbalances. Another issue is poor condenser heat dissipation, where clogged fins filled with willow catkins or insect debris hinder cooling, preventing pressure buildup. These problems all require professional pressure gauges to diagnose high and low pressures accurately. I advise car owners not to tinker blindly—damaging the compressor can lead to costly repairs. It's best to have a reliable repair shop conduct a thorough inspection.
