Checking The Ac Pressure
The first thing you should do before making any judgments is to check the pressure of your air conditioning system. Performing the pressure check will provide you with the assurance you want that it is, in fact, the pressure that is excessive and creating the problem.
If youre interested in learning more about this subject, you should watch this video:
Could It Be A Problem With The Condenser Fan Or Fan Motor
The condenser fan in your cars air conditioning system may be operated at a variety of capacities as well as speeds. It is extremely conceivable that any type of fault with the condenser fan may cause it to run at a lower speed and so impair its efficiency. This, in turn, will result in the fans incapacity to effectively cool the system and allow for adequate circulation.
What Are The Symptoms Of An Overcharged Ac System
Based on the common signs below, it is swift for you to detect that the AC is overloaded:
- The cooling AC is faulty, most evident because the air is only slightly cooler than room temperature, and the cooler can even blow out hot air.
- The compressor is noisy or damaged.
- The engine is not working efficiently, which can cause the car to slow down and consume more fuel than usual.
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How To Remove The Overcharged Freon
If your system is overcharged with Freon, the first thing youll need to do is remove the excess Freon. This can be done by releasing some of the Freon through the low side pressure relief valve.
Once youve released some of the Freon, youll need to have a certified mechanic check the system for leaks. Once any leaks have been repaired, the mechanic will be able to properly recharge the system with the correct amount of Freon.
Ac Low Side Pressure Too Low And High Side Pressure Too High

- Check the temp of the line on the high pressure side before and after your repair. You may have caused a restriction, which will show up as high temp before and lower temp after.
- Check your fans — both should be spinning. In my case the main fan was toast , if so replace that.
- Check the temp across your condenser while running. If you notice that half of the condenser seems cold, there may be an issue with it/a restriction. In general they tend to get hit with road rash and whatnot which diminishes their performance over time. The condenser is only $45 on rock auto so you may just replace it.
- Moisture or air contamination in the system — if you had a leak in one of your fittings the vehicle could suck some air in while charging.
- Check your expansion valve — they recommend you replace the mechanical one in the 6th gen every time you service the vehicle.
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Can I Buy Freon Myself
Yes, you can purchase Freon from most auto parts stores. However, its important to be aware that this is a potentially dangerous task. Recharging your AC system with Freon can cause serious injuries if its not done properly. For this reason, its always best to leave this job to a certified mechanic.
Problems With Ac Pressure
The high pressure within the condenser fancan leads the aluminum to deform and the evaporator coils to leak, resulting in a faulty cooling system. Because the compressor may need to be repaired or replaced, the cost of repair and replacement is considerable because the dash may need to be removed. Air pressure that is higher than normal is generally the result of two circumstances. One possibility is that your air conditioning system is experiencing restricted or non-existent airflow through the condenser.
If there is debris near the fan that is obstructing the flow, you will experience the same problem.
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What Causes Low Pressure On High Side Of Ac
The Reasons for the Appointment ofAC Pressure on the low side is high, while on the high side is low. The air conditioning system in your automobile might experience a variety of issues. There might be a variety of factors contributing to this scenario, including a malfunctioning compressor, low refrigerant levels, problems with the heater or AC settings, among others. In the Lower Lowland Side pressures that are extremely high Lowerthan normalpressureon both the high and low sides, even with the proper quantity of refrigerant, might indicate a problem with the systems ability to produce pressure or that too much heat is being lost at the condenser.
- Also Do you know what generates excessive pressure in an air conditioning system?
- The temperature differential between the condensing temperature and the ambient temperature will decrease, and the refrigerant gas will not condense until the headpressure climbs above the condensing temperature.
- One of the most prevalent reasons for high flow and head pressure at an air conditioner or heat pump compressor motor is because: Because of a refrigerant leak or an incorrect charge, the refrigerant level is too low.
- What are the signs and symptoms of an overcharged air conditioning system?
What Is The Receiver/drier In My Cars Ac
The receiver/dryer is a component of your air conditioning system that stores and dries the refrigerant used in the air conditioning. It contains something known as a desiccant, which is comparable to those small packets that you would find in a new pair of shoes or other items that are intended to keep the wearers feet dry. They are often labeled with a warning that they should not be consumed. The desiccant in your air conditioning machine performs the same function. It draws moisture from the refrigerant and absorbs it, preventing the refrigerant from becoming polluted with water.
If you have an excessive amount of water in your system and the receiver / drier is overloaded, it will be unable to perform the functions it is designed to perform.
That in turn can cause issues with your air conditioning compressor and expansion valve as well as the problem of your low side pressure being too high and your high side pressure being excessively low.
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What Is A Cars Ac Compressor
The compressor is the component of your vehicles air conditioning system that is responsible for creating the pressure that the coolant is forced to operate under. If there is a problem with the pressure in your air conditioning system, this would be the first place to examine. In order to maintain pressure on both sides of the compressor, it must first rise pressure before passing through your air conditioning system to the condenser, where it converts from a gas to a liquid, and then drop pressure while the cooling process occurs.
If your compressor is not operating in the manner in which it is meant to, the pressure in your air conditioning system will most likely be significantly impacted as a result.
What Is The Pressure Switch In My Car’s Ac
If it’s not the compressor that’s causing trouble for your AC pressure, it may be your pressure switch. The pressure switch is mounted on both the high and low sides of your air conditioning system and it monitors the pressure of the refrigerant as it travels through. The point of the switch is to turn off the compressor to prevent damage if the pressure is too far out of line for the system. If the switch fails, then this is not able to happen and it can result in your pressure being thrown out of whack.
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Low Side Pressure Is Too High
Finally, if youre wondering why your AC pressure reads too high on the low pressure side, while the high side pressure remains normal, you might be dealing with incorrect cycling of the condenser.
This happens when there is an unusually rapid cutting in and out of the cycle. Its not a common occurrence, and requires a professional to resolve the issue. Youre also likely to be dealing with a thermostat switch malfunction due to a wrong temperature gauge, and in such case, the thermostat switch needs to be replaced by a mechanic.
Ac Low Side High High Side Low: Why Does This Happen

The pressure reading from the low side should be between 25 and 30 psi, and the pressure reading from the high side should be between 200 and 250 psi, respectively. However, if you notice that the AC low side is high and the high side is low, such as the low side is 100 and the high side is 150, it is possible that one of the internal components is faulty. Possible explanations for this might include an excessive quantity of Freon being sent to the evaporator. It is also possible that the thermal bulb has failed and is no longer able to detect temperature signals, or that the TXV has been stuck in the open position.
This tube serves as an expansion valve, allowing the quantity of refrigerant that flows to the evaporator to be controlled.
This issue occurs if the o-ring seal located outside of the orifice tube becomes worn out.
Before selecting whether or not to replace the compressor, you should inspect the pressure switch, expansion valve, and compressor clutch, among other things.
Determine whether or not it is providing the right reading using an Ohmmeter.
In a similar vein, when you power on the system, the fan has to start spinning.
However, it is always a good idea to contact with a professional before replacing any element of your vehicle.
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What Happens If The Readings Arent Normal
If you find that when you measure the pressure on the low side of your air conditioner, it rises above 100, while the pressure on the high side drops to around 150 or lower, you have a problem with the low side being high and the high side being low, you have a problem with the low side being high and the high side being low.
Obviously, this indicates that there is a problem with the air conditioning machine itself, which is causing this to malfunction.
What Do Lower Low
This condition usually means there is a restriction in the system or the TXV or orifice tube is blocked or closed. Feel the lines is there a pressure/temperature drop at the TXV or orifice tube?
- If there is a drop, there may be a restriction at the TXV or orifice tube.
- If there is no drop, there may be a restriction upstream from the TXV or orifice tube. Follow the liquid line back towards the condenser to see if you can feel a pressure/temperature drop.
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The Importance Of Ac Readings
Car air conditioners are delicate pieces of equipment. The main function of an AC system is to remove hot air and humidity. Adding cool air is a by-product of this function. Your cars AC system can develop issues, especially in the low and high-pressure lines.
High low AC pressure readings can develop. At first, they may not pose any problems to your cars performance. Over time, if you continue to ignore these issues, your AC system will deteriorate.
Driver adjusting the AC system.
AC readings refer to the pressure readings of your cars air conditioning system. They reveal if the AC unit is working correctly or not. The readings can detect damage to the system. If the temperature readings rise above normal levels, there is likely an issue with the AC.
Your cars AC unit needs to stay within a certain pressure range. If the pressure gets too high and continues at this level, it will eventually cause compressor failure, which is expensive to fix.
Other Common Ac System Issues
Aside from the ones Ive already mentioned above, there are a few other problems that might be going on with your malfunctioning AC system. These include using an inappropriate compressor lubricant, having a low or old oil system, or issues with loose wirings and slipping belts.
Most of these issues and more can be exposed when you rigorously test your AC systems pressure readings, and you have a clear understanding of what each reading means. But, for a closer inspection and a more accurate diagnosis, its still best to take your car to the local mechanic.
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How Does An Ac System Work
The modern AC system hasnt changed much in the last 60-odd years. Sure, its considerably more efficient now, but the principles governing it are pretty much the same a bit like the internal combustion engine.
Heres a fundamental fact that most people dont quite grasp. The main job of the AC in a car isnt to push cold air into the vehicle. Instead, its to remove the hot air and associated humidity. Sure, adding cold air in is a by-product, but its not the primary purpose.
Here is an example of an AC system. Have a quick watch this video is 7 minutes long but well worth your time.
The serpentine drive belt is attached to the crankshaft the power output shaft of your engine if it helps to think of it that way. This belt can drive several components, depending on how the company designed the car. These components might include the alternator, the power steering pump, and such as is relevant to this article the air conditioning compressor.
From the compressor, two lines lead in/out. These are what we call the high-pressure and low-pressure sides of the compressor. They contain a fluid the refrigerant.
You can tell which side is which from a quick look at your air conditioning system. The larger-diameter pipes are lower pressure. The pipes with a narrower diameter are high pressure.
The next component is the thermal expansion valve. This turns the hot liquid into a cold gas. Following this, the gas passes through the evaporator.
How Do You Release Pressure From Low Side Ac
Though there are ways and steps you can follow to release pressure from low side AC, this work should be left to professionals only. Any wrong action could lead to a bigger and more costly problem to the AC system. Taking your car for pressure release could be expensive, but its right.
Here are the steps to release pressure from low side AC if youre a DIY enthusiast.
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Possibility #2 Ac Low Side Pressure Is Too High Because Theres Air In The System
An AC system is a closed system. If youre low on refrigerant its because you have a leak. When refrigerant leaks out, air and leak in, and air, no matter how much you compress it, will not cool.
One way to check for air in the system is to watch the high-pressure reading. Run the system for about 5-mins and shut it off. If the high side pressure drops from around 150-200 to around 28-psi quickly and then falls gradually after that, youve got air in the system.
What Happens If The Readings Aren’t Normal

If you’re finding that when you measure the pressure on the low side of your AC and it’s coming up above 100, while the pressure on the high side is down around 150 or lower then you have a problem with the low side being high and the high side being low. Obviously, that means something is wrong inside the air conditioning unit itself that’s throwing this off.
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What Do Your Car Ac Pressures Mean Ac Pressure Readings Telling About My Ac Pressure
Now, how would you know if the AC pressure of your car is too high or maybe too low? Whats the perfect number to have for your AC pressure? Before I go ahead and answer those, I would like to begin with the meaning of AC pressure numbers.
Usually, there is a gas called refrigerant in an AC, which is responsible for all the temperature control. It changes its state in different pressure ranges. With the proper pressure PSI, it will act adequately and keep your car cold through the AC. So, the AC pressure on your car means it has the right PSI to properly process the refrigerant.
Typically, you dont need to worry too much about low pressure as they dont impact the performance. What you should be looking at is the PSI of high pressure. The best PSI to have as your higher pressure is 150 PSI.
However, you may get different readings on your car AC. So, lets take a look at what those different readings mean for your AC.
Usually, whenever you see these readings on your AC pressure, you should have these particular problems. So, when you know the problems, you will be able to fix them quickly. Thats why knowing what the readings mean can be very crucial for you.
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