What is the reason for low low pressure and low high pressure in car air conditioning?

[SanKyle]

The reason for low low pressure and low high pressure in car air conditioning is due to the failure or damage of the air conditioning compressor. The following is relevant information about car air conditioning compressors: 1. Introduction: The car air conditioning compressor is the heart of the car air conditioning refrigeration system, responsible for compressing and transporting refrigerant vapor. Common reciprocating compressors include crankshaft connecting rod type and axial piston type, while common rotary compressors include rotary vane type and scroll type; 2. Classification: According to different working principles, air conditioning compressors can be divided into fixed displacement compressors and variable displacement compressors. The displacement of a fixed displacement compressor increases proportionally with the increase of engine speed. It cannot automatically change power output according to refrigeration needs and has a relatively large impact on engine fuel consumption. Variable displacement compressors can automatically adjust power output based on the set temperature. The air conditioning control system does not collect the temperature signal from the evaporator outlet but controls the compression ratio of the compressor based on the pressure change signal in the air conditioning pipeline to automatically adjust the outlet temperature.

[DeCalvin]

As someone who has long studied car air conditioning systems, I believe the main reasons for both low high and low pressure are often insufficient refrigerant or leaks. When there's less Freon in the system, the overall pressure naturally drops. The compressor can't draw enough gas, so the high pressure can't rise, and the low pressure also decreases. Another possibility is system blockage, such as a dirty filter or bent pipes, where restricted flow causes pressure to drop. Low ambient temperatures can exacerbate this situation, but it's usually not the root cause. I recommend checking for leaks as soon as possible, repairing pipes, and replenishing refrigerant to avoid compressor damage from running dry. Long-term neglect can lead to poor AC performance or even complete failure, making the car unbearably hot in high temperatures and affecting driving. Regular maintenance is key—use a pressure gauge to measure high and low pressure values and compare them with the manual to avoid many troubles. Remember to prioritize safety and avoid direct contact with refrigerant during operations.

[ParkerAnn]

In over a decade of auto repair experience, the most frequent cause of low pressure on both high and low sides of car AC systems is complete refrigerant leakage. Common culprits include loose pipe connections, aged cracks, or condenser perforations. Compressor failures such as bearing damage or piston wear can also cause insufficient suction leading to dual pressure drops. Issues with the expansion valve, like jamming or regulation failure, similarly result in reduced flow and dual pressure decline. Remember – if AC airflow isn't cold and pressure gauge readings drop rapidly when activated, address it immediately before summer repair shop queues form. Other rarer possibilities like system design flaws or initial undercharging during refrigerant replenishment require comprehensive diagnostics during troubleshooting to prevent repeated repairs.

[VanDerek]

As an average car owner, I always emphasize not to overlook daily maintenance. Low pressure in both low and high sides often indicates refrigerant leakage caused by insufficient accumulation. Regularly inspect pipeline joints to avoid cracks, and recharge the refrigerant once a year to ensure adequate levels, which can prevent many malfunctions. Preventive measures like briefly running the air conditioning during winter startups help prevent blockages and prolong seal life. On hot driving days, monitor cooling performance and conduct early inspections to avoid sudden breakdowns and costly repairs. Remember, minor neglect can lead to major issues and higher expenses—timely action is wise.

[VanMorgan]

From a cost perspective, I've encountered car owners with AC issues where both low and high pressures were low. If it's just a refrigerant shortage, topping it up is cheap—just a few hundred yuan to fix. But delaying repairs can lead to compressor failure, costing thousands for a replacement. Expansion valve malfunctions also cost around five to six hundred yuan to repair. Regular check-ups are small expenses that save big money. Before repairs, consult multiple shops for quotes and choose the most economical option. Don't just go for the cheapest and use inferior parts, as rework will cost more. In summer when demand peaks, repair costs rise—address issues early to avoid hefty expenses.

[LaLeonardo]

Prioritize driving safety. I'd like to remind everyone that low AC pressure, high pressure, poor cooling, and high temperatures can significantly increase the risk of heatstroke and reduce driving concentration, creating multiple hazards. In hot weather, if encountering such situations, you should park the car, open windows for ventilation, and avoid continued AC usage. Seek immediate repair and maintenance. Safety comes first—don't overlook comfort-related risks and potential hazards.