# Question: What Would Cause Excessive Pressure On The High Side Of An AC System?

## What are the symptoms of an overcharged AC system?

In summary, there are seven symptoms or telltale signs of a system that has too much refrigerant.High discharge temp.High subcooling in the condenser.High pressures in the condenser.Higher condenser splits.Normal-to-high evaporator pressures.Normal superheats.High compression ratio..

## What should AC pressure be with engine off?

That’s normal with the compressor off. Then watch the pressures when you turn it on. The low side will drop to 25-40psi, and high side should go to around 150-200psi.

## What should AC gauges read on 134a?

R134a Pressure Gauge ChartAmbient Temperature (°F)Low SideHigh Side80°45-50 psi175-220 psi75°40-45 psi150-175 psi70°35-40 psi140-165 psi65°25-35 psi135-155 psi6 more rows•Jan 13, 2018

## What should the pressures be on a 134a system?

For the normal running pressure in an R134A system, the coil should run at 22 pounds per square inch at the lowest temperature, 45−20 = 25 degrees Fahrenheit. Similarly, at the highest temperature, 60−20 = 40 degrees Fahrenheit, the coil should run at 57 psi.

## Is my AC overcharged?

Inefficient Cooling The most obvious sign of an overcharged AC system is poor cooling. Without room to depressurize the coolant, the AC system simply stops functioning. You might still get a cool breeze coming from the vents, but just as often you could get room-temperature or even hot air.

## What would causes high pressure on the low side of a AC system?

What is An Expansion Valve in My Car’s AC? The expansion valve failing is another thing that can cause the pressure on the low side to go too high and the high side to go too low. Your expansion valve is located at the evaporator and regulates the flow of refrigerant through the AC system as a whole.

## What should high side AC pressure be?

The low-side should be near 30 PSI at 90 degrees Fahrenheit or less. Pressure that is too much lower or higher shows there is a problem. On a properly working system, high-side pressure will be about twice the ambient temperature, plus 50 PSI.

## What causes high pressure in car AC system?

Mechanics often misdiagnose high-pressure gauge readings in a car’s air-conditioning system. … Most high-pressure readings are a result of the freon or refrigerant not cooling adequately. Insufficiently cooled freon automatically causes the pressure to increase.

## Can overcharged AC cause overheating?

Also, if you recently recharged your a/c (especially if you converted to R34 and didn’t reduce the volume of refrigerant to 80% of factory recomended capacity) you may have the system overcharged, which will cause the engine to lope at idle, and believe it or not… overheat!

## How do I know if my AC high pressure switch is bad?

Symptoms of a Bad or Failing AC Pressure SwitchAC system cutting on and off rapidly. Repeatedly cycling on and off is part of the normal operation of an AC system. … Unable to cool the car. If either of the AC pressure switches fails, then the system will have a difficult time maintaining the pressure required to function properly. … Compressor not coming on.

## Will low refrigerant cause high pressure?

Condenser subcooling is a good indicator of how much refrigerant charge is in the system because low condenser subcooling can mean a low charge. … The excess refrigerant will accumulate in the condenser, causing high subcooling and high head pressures.

## What happens if refrigerant pressure is too high?

The system might be overcharged It is advisable that you do not add refrigerant during this time to avoid damage to the evaporator core. Too high a pressure may result in a leak on the evaporator’s thin aluminum and its folded seams, the condenser piping, and other thin parts of the piping system.