Your car’s air conditioner is helpful to regulate engine temperature for maximum fuel economy and minimum emissions. Proper use of the car’s air conditioning system is important. Otherwise, you may face problems such as reduction in fuel mileage and excessive stress on the engine. Your car’s AC pressure will let you know everything about your air conditioning system.

Car AC Pressure: High-Side and Low-Side

You need to measure high-side and low-side ac pressures to completely understand the functioning of your car’s air conditioning system. The pressure gauges that feature a small refrigerant can display the low-side pressure or the pressure right before the compressor. The low-side pressure gauges are inexpensive to build and easy to identify. Since they measure low pressure, they do not need to be precise.

The high-side pressure requires an advanced gauge and different connection, as it is hundreds of PSI higher than the low-side pressure. An AC gauge set is required to measure the high-side pressure in your car’s air conditioning system. The AC gauge sets come with a gauge for the high-side and low-side pressures, sight glass to help you observe the condition of your refrigerant, and line to connect your system to a refill can.

Like your engine oil dipstick, your air conditioning system does not have a set level. There is a range of low-side and high-side pressures that are acceptable and vary depending on the ambient temperature. However, generally your low-side pressure should be 30 to 40 PSI and high-side pressure should be 150 to 175 PSI. Everything in your air conditioning system should be working normally if low-side and high-side pressures are in range. Otherwise, you should check your ventilation system for operational faults or a clogged expansive valve or condenser.

Related Reading: Car AC Blowing Hot Air: Reasons and Their Remedy

You need to add refrigerant if you find low pressures on both sides of your air conditioning system. You might have added too much refrigerant if you find high pressures on both sides of your system. A faulty compressor may be a problem if your low-pressure gauge reads high and the high-pressure gauge reads low. The blockage of the expansion valve or orifice tube may be a problem if your low-pressure gauge reads low and high-pressure gauge reads high.

Call us today or schedule an appointment with us to set the right AC pressure in your car and check the performance of your AC.