If no obvious leak is found, recover the refrigerant and replace the service ports or valves, evacuate and recharge the system, and add dye in case there is another leak. You just need to hook up a gauge set to the AC system and record the pressures on the low side and the high side. If the condenser runs through this cycle more quickly than it's supposed to then the pressure on the low side is going to increase more than is normal. This can essentially destroy your entire air conditioning unit. If your compressor it's not working the way, it's supposed to then obviously the pressure in your AC system can be severely compromised as a result. The compressor is the part of your air conditioning system that actually creates the pressure that the. When you measure the high-pressure side of your air conditioning system you should be getting anywhere between 200 pounds per square inch and 250 pounds per square inch. manifold gauge shows vacuum on low side and no pressure on high side. It's possible that you might have a problem with your pressure switch, your expansion valve, or the receiver / dryer also. If you are low on refrigerant, it leaked out somewhere. The air conditioning system in any car is one of the most finicky systems that you have. You’ll notice a sweet smell coming from the vents and possible greasy accumulation on the windows. Your best bet if you know that the pressure is off in your air conditioner is to get it to a mechanic so they can narrow down the exact cause of the problem and get it fixed for you safely and quickly. Blockage on the high-pressure side of the system between the compressor and condenser but before the high-pressure port. If the switch fails, then this is not able to happen and it can result in your pressure being thrown out of whack. The low side pressure in your air conditioning system should drop down significantly when your engine is running and your AC compressor is cycling on. Look for oil residue around the hose ferrules, fitting connections at the compressor, condenser, and evaporator or expansion device. If the pressure on the high side and the low side match what is recorded for the ambient temperature around your air conditioner then you don't have a problem with the pressure of your coolant. Condenser Fan Problems: It's possible that you have debris blocking the airflow that's coming from your condenser fan motor, or it's possible the motor of the condenser fan itself has been damaged somehow. If you missed part I, start here. Obviously, this would be a clear place to look if there's a pressure issue in your AC system. From that point all you need to do is compare it to the ambient temperature and the pressure is listed on the number chart for your particular air conditioning unit. A new compressor may cost you a couple hundred dollars to buy and get repaired. You can buy an AC pressure gauge on. From that point all you need to do is compare it to the ambient temperature and the pressure is listed on the number chart for your particular air conditioning unit. If the expansion valve fails then the coolant levels can be thrown off. Refrigerant is undercharged; Excessive condenser water flow; Condenser outlet water temperature too low; Air conditioner unit is over capacity; Ineffective compression of compresor or valve is damaged; Ambient temperature too low; Low Pressure Side Too High. The temperature that your air conditioning is able to produce is directly related to the pressure in the overall system. It's possible that you might have a problem with your. When you hook up the gauge to your AC system to measure what the pressures are, on the low side the gauge should be giving you a reading somewhere between 25 pounds per square inch and 30 pounds per square inch. Get the BEST auto repair information Alldatadiy.com and Eautorepair.net are professional-grade shop manuals—period. Anyway, I hooked up my manifold gauges and the low side pressure maxed out the gauge! Overcharged System: The other reason you might be experiencing high pressure is even when the engine is off is that your whole air conditioning system has been overcharged. One of the problems that can pop up with your air conditioning is when the pressure on the low side of the compressor is running high, while the pressure at the high side of the, Determining the pressure in your AC system is not entirely difficult to do. 5. This can essentially destroy your entire air conditioning unit. Let us go through the causes and solutions of these vital dilemmas here. This could be normal if outdoor temps are very low. Compressor turns off then slowly goes back to about 30 psi. If you're finding that the low side pressure is higher than it should be while the high side pressure is about normal, then you're probably having an issue with your condenser. or so if you want to do this yourself. The pressure on the low side reads 35 PSI while the high side reads 275 PSI! fan itself has been damaged somehow. : The other reason you might be experiencing high pressure is even when the engine is off is that your whole air conditioning system has been overcharged. Check you car manual for specific guidelines. Car AC Pressure Too High – The Causes And Solutions. If the pressure is high when it's running, then that might just be normal operating procedure. (very common especially if you’ve tried to add refrigerant yourself). But if you see the AC low side high, high side low , such as the low side is 100 and the high side is 150, there might be problems with any of the inner components. If the expansion valve fails then the, What Happens When Your Heater Core Goes Out? This isn't really the kind of job you want to do on your own in the driveway by any means. A bad check valve on an air conditioner, heat pump or similar HVACR equipment can show up as abnormally low or abnormally high suction line pressures, or as abnormally low or high superheat. This happens when there is an unusually rapid cutting in and out of the cycle. If you have too much coolant going through the system it could end up freezing and if there's too little then the evaporator may overheat and cause damage. Check blend door operation by turning the temperature dial on your car’s HVAC and watching blend door operation. Low head pressure may occur simulataneously with high pressure on the suction side of an air conditioner, heat pump or refrigeration system compressor system. Low side pressure is too high (high side pressure is normal) Finally, if you’re 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. Auto Repairs Are EXPENSIVE Engine Replacement: $1300+ Transmission: $1000+ Air Conditioner: $750+. Therefore, you should get this part replaced or checked by an experienced mechanic. You can buy an AC pressure gauge on Amazon for about $30 or so if you want to do this yourself. The pressure is going to need to be released somehow, and it's best to leave that to a mechanic to get the job done safely and properly. The expansion valve controls the flow so that it stays at optimal levels and keeps the evaporator temperature where it needs to be. If you use your gauge and determine that your low side is up over 100 and your high side is down around 150 then odds are a mechanic is going to tell you that the problem you're dealing with is your compressor has failed. 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. Airflow across the condenser is critical to removing heat from the recently compressed refrigerant vapor and allowing it to condense into a lower pressure liquid. RE: 1995 Mercury Villager GS Problem: AC only cooling intermittently. If you have too much water in your system, and the receiver / drier is overloaded then it will not be able to continue doing what it's supposed to do. The pressure will cycle between the low and the high sides, so wait till it clutch engages to get the correct readings. AC symptom #3: Low side pressure is too high, High side pressure is high Here are the possibilities 1. Replace expansion valve, flush and install in-line filter. Fix: Evacuate the system. It's also possible that air has gotten into the. All Rights Reserved. The compressor is the part of your air conditioning system that actually creates the pressure that the coolant is under in your vehicle. Determining the pressure in your AC system is not entirely difficult to do. Experts suggest using an IR heat gun or similar tempeature measuring tool to check the tempeature of the refrigerant line on each side of the valve. Fix: Clean condenser fins and check for dented condenser tubes. High Pressure Side Too Low. That way you can at least tell for yourself that this is the main issue and not one of the other host of issues that could potentially cause problems with your car's air conditioner. However, if there’s a restriction on the high side of the system in the receiver/dryer, a crimped tube in the condenser or crud accumulation in the condenser or the expansion valve or orifice tube, there’s … On a properly working system, high-side pressure will be about twice the ambient temperature, plus 50 PSI. Generally, these can be found online, and you may also be able to find the correct pressure listed in the owner's manual for your car. Alldatadiy.com, on the other hand, uses the factory diagrams. Pressure that is too much lower or higher shows there is a problem. The following table presents the possible inferences and the actions that can be taken, based on the level of pressure registered by the high and low pressure gauges: The high-side pressure, which the FSM gives only somewhat roughly as higher than 2xx psi (my GM manuals have pressure tables based on humidity and ambient temp, it changes a lot), never goes above about 150 psi at 1500 rpm as specified. Is It Cheaper To Rebuild An Engine Or Replace It? is under in your vehicle. If both of your numbers are in these ranges, then everything is working the way it should be and you shouldn't have too much to worry about in terms of your AC system. Expansion valve and compressor already replaced. Getting your air conditioner serviced, especially if you need to drain the refrigerant and put new stuff in, is something that has to be done using the exact right tools by a professional. Your expansion valve is located at the evaporator and regulates the flow of refrigerant through the AC system as a whole. However, I noticed on the AC gauge manifold that the low pressure side consistently reads too low while the high pressure side reads too high. R-134a TEMPERATURE PRESSURE CHART (Tabla de Temperaturas y Lecturas) Ambient Temperature °F / °C (Temperatura Ambiental): Low-Pressure Gauge (Puerto de Servicio del Lado de Baja Presion): High-Pressure Gauge (Puerto de Servicio del Lado de Lado de Alta Presion): 65°F (18°C) 25-35 psi / 172-241 kPa: 135-155 psi / 931-1069 kPa The pressure reading from the low side should be between 25 and 30 psi and the high side between 200 and 250 psi. This could be the result of a problem with your thermostat switch or temperature gauge but you're going to need a mechanic to diagnose this one properly for you. Engine Problems with Honda CRV: Customers Had To Pay Up To $3700 On Repairs! Note: The most ideal pressure readings are around 150 high and 30 low. Evacuate and check for blockage. If the condenser fan is under too high pressure it can warp the aluminum and cause leaking from the evaporator coil. 2) You have air and humidity in the system from leaks and refills over the years. That's the result of either too much refrigerant being put into the system or too much oil. An A/C System that is working properly should have 150 PSI on the high side and 30 PSI on the low side. Let’s Find Out The Pros and Cons Of Each! If the ambient temperature is higher or lower than normal (70 to 80°F) the pressures will go up or down accordingly. Your condenser has a cycle that it goes through in order to allow your air conditioning to run properly. 1. After doing a vacuum test and not having a leak, then recharging it and having the high pressure line pressuring, yet the low side didn't change. Obviously, this would be a clear place to look if there's a pressure issue in your AC system. The best way for you to tell if you have a problem with the low side being too high in your air conditioner and the high side being too low is  by the pressure gauge that we linked to above. High side stays around 100 to 120 psi. In most cases, their diagrams are right from the factory manuals. 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. 2013 Ford Escape Problems – What You Need To Know! Replace clogged orifice tube and flush hoses. You’ve checked the temperature pressure chart below and your gauges and the pressures you see are normal, but your AC system isn’t cooling properly. Engine coolant levels will be low. Obviously the main issue that people deal with when they have a broken A/C system is that the air coming out the vents is not cold enough. Yo… This will reduce the airflow through the condenser and that in turn means it's not going to be able to cool down the AC system. There are a few too many variables for this one to just be handled on your own, or for the reason for this problem to be refined down more than what we've said. Fix: Replace a bad blend door actuator or faulty heater control valve or repair a faulty blend door or blend door linkage. The car will not turn the AC compressor on, probably because these pressure are out of wack. As we've established, there are two different sides to your AC system that have two different pressures. If you turn your car on and turn the AC to high and check the AC pressure lines, the low pressure side should read around 30 psi and the high pressure side should read around 250psi. It has something inside of it called a desiccant, which is similar to those little packets, but you might find in a pair of new shoes or other products that are meant to stay dry. 3. Fix: None needed. Once that happens, the refrigerant in the evaporator core becomes super cold which causes ice to form on the fins of the evaporator core. If the pressure is too high than what the chart indicates is normal then that means you have an overcharged system and if it’s lower it means that you might have a refrigerant leak somewhere in the line If you have zero pressure then it means you have no coolant at all and it's likely leaking entirely from someplace. The refrigeration side of your air conditioner needs to be at the correct pressure in order to produce the temperature required to cool down the vehicle. However, Alldatadiy.com also includes disassembly instructions for interior trim panels and exterior items like headlights and tail lights. Once it circulates back to the compressor it is repressurized as the whole process continues. Pressure Range Low side: 0 to -29.99 psi High side: 71 to 85 psi Indications Low pressure side becomes a vacuum High pressure as listed above Frost or condensation on the front and rear pipe connections of the receiver dryer or expansion valve Causes AC system is blocked by contamination or ice Recharge. Engine Problems Chevy Equinox: Will You Stand Excessive Oil Consumption and Complete Engine Failure? I hope that refrigerant didn't contain sealant, because that is death to an a/c system. Evacuate and check for blockage. For instance, on a 90-degree Fahrenheit day, … If you are experiencing a problem with how your AC works, but you also have these normal ranges of low pressures on the low side and high pressures on the high side then it means you have a problem somewhere else in the system. Check for debris on the orifice tube screen. Low side pressure at 50-55psi could be low charge, overcharge, bad compressor, weak compressor, low air flow over condenser, stuck open expansion valve, or many other things. Possibility #3 AC low side pressure is too high because the condenser has reduced airflow. If the pressure is too high than what the chart indicates is normal then that means you have an overcharged system and if it’s lower it means that you might have a refrigerant leak somewhere in the line If you have zero pressure then it means you have no coolant at all and it's likely leaking entirely from someplace. The blockage or stuck expansion valve restricts the flow of refrigerant into and out of the evaporator. It's also possible that air has gotten into the coolant system and is raising the pressure as well. Clogged condenser fins or an inoperative condenser fan can cause low side pressure to be too high. The pressure is going to need to be released somehow, and it's best to leave that to a mechanic to get the job done safely and properly. l. Defective winding Or There can be a number of problems that crop up with air conditioning not working at all to working at a diminished capacity. Although there are a number of reasons that can make your low side pressure go too high, and the high side pressure go too low, when it comes to both of them happening at the same time you have some limited options. The expansion valve controls the flow so that it stays at optimal levels and keeps the evaporator temperature where it needs to be. Fix: Remove excess refrigerant or evacuate and recharge with the correct amount. To know for sure that this is the problem you do need to test it when the engine isn't running as pressure goes higher when you do have the engine on, as they're supposed to. 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