There’s nothing quite like the suffocating and painful sensation of stepping back into your car after it has been sitting for a few hours in the sun. Boiling leather seats combined with thick, musty, hot air doesn’t make for a great experience. Luckily, cars nowadays come fitted with great air conditioning systems. Switch it on, and the whole car will cool off in no time. But then, it’s when your car’s air conditioning system starts blowing warm air into the car that you know you’re in trouble.
It’s very likely that the issue lies with the expansion valve, which is also known as an orifice tube in some car models. The valve works by regulating the flow of refrigerant, a mixture or substance used to keep the airflow cold. This guide will explain how to determine if the issue does lie with your expansion valve, how to find a good replacement for your valve or tube, and finally, how to actually replace it. Please note that this job should probably be completed by a professional. However, if you feel up to and have the appropriate equipment, please read on.
What’s Wrong With Your Car’s Air Conditioning?
When your car’s air conditioning system starts blowing out warm air, it’s easy to get frustrated. But then, before you start taking apart your car’s air conditioning system and purchasing new parts, it’s essential to identify exactly what’s wrong with your expansion valve. Here are three common problems that are fairly simple to identify.
1. Refrigerant Leak
Refrigerant leaks are sometimes hard to spot. This is because the refrigerant liquid instantly evaporates as gas if it’s not being contained at the correct pressure in the air conditioning loop. Because the liquid will turn to gas upon leaking out of the loop, it won’t appear as a puddle or spillage. Instead, keep an eye out for an oil-like residue on the A/C hose units and connections. If you’re unsure of how to spot a refrigerant leak, a team of professionals can test your vehicle using UV dyes and other specialized test equipment.
2. Problems With The Electrics
Your car’s air conditioning is comprised of a complicated wiring system made of a myriad of different electrical components. If any of these components malfunctions or stops working for whatever reason, the whole system is designed to shut down as a safety measure. This issue will need to be spotted by a professional engineer or mechanic with the right testing equipment.
3. Problems With Your Expansion Valve Or Orifice Tube
If your air conditioning unit is blowing hot rather than cold air, likely, the expansion valve isn’t functioning correctly. Another symptom to look out for is frost forming where the air is released. Sometimes, when the expansion valve or orifice tube stops working, cold air begins to blow unmetered, and this can cause the evaporator to freeze over. Both of these problems occur when the orifice tube stops being able to regulate the refrigerant. Too much and your car will be too cold; too little and it will be too hot. The next step will be to think about replacing the orifice tube.
What’s An Orifice Tube?
What exactly is an orifice tube, and how does it work? As explained above, your car’s air conditioning system uses refrigerant, which is the substance used to change the air’s temperature. It exists within a pressurized loop in your air conditioning system. An expansion valve or orifice tube (depending on your car model) is used to meter out the correct amount of refrigerant. As the refrigerant enters the evaporator in liquid form, it passes through the expansion valve. Here, the pressure is removed from the refrigerant, causing it to expand and cool into a vapor. In the air conditioning cycle, it’s at the point where the air meets the orifice tube that the air is the coldest. An orifice tube is a key component of the air conditioning system in any car, and if it stops working properly, the whole system will become ineffectual. If the air flowing through your car’s system is never cooled or is cooled too much, your car will be unable to keep the air inside the car at a regulated, pleasant temperature.
What Type Should You Get?
If you believe that you’ve determined that the orifice tube in your car’s air conditioning system definitely needs replacing, you’ll have to purchase a new one before you can start the replacement process. Please note that having all the parts before you begin dismantling the parts of your air conditioner is crucial. Leaving the loop open exposes it to all sorts of problems that can arise from contamination.
Aclube.com is a great place to start if you’re in the market for a sturdy, durable orifice tube. They have a variety of orifice tubes to choose from. Their tubes are designed to fit seamlessly into Fords, Chryslers, GM’s, and Audi’s, and come in a variety of colors. Be sure to double-check the specific size of your old orifice tube by searching your car type. You’ll also need to purchase o-rings for the line that contains the orifice tube. These parts can also be purchased at aclube.com. Be sure you find the perfect fit, as o-rings of the wrong size will cause other problems such as leaks.
How Do You Replace It?
The replacement process is fairly complex and can be challenging to follow if you’re inexperienced with mechanics and electrics. If you’re at all unsure, look into hiring a professional who can replace the orifice tube for you.
The basic steps in the replacement process are as follows:
- All refrigerant is removed from the system.
- The defective orifice tube is removed.
- The new orifice tube is installed.
- Refrigerant is recharged into the system.
- Removing refrigerant from the car’s air conditioning system
You’ll first need to use a refrigerant identifier to determine what type of refrigerant is being used. If it’s clean and safe to remove, this tool will tell you after taking a small sample. Once you’ve determined that the refrigerant is safe to remove, you must then connect the refrigerant recovery system. Using the low-pressure port on the system, open the valve on the storage tank and let the machine empty out the refrigerant from your vehicle. This can take as long as half an hour to complete fully.
1. Removing Your Faulty Orifice Tube
You’ll find the old orifice tube inside the high-pressure line that leads toward the evaporator. Usually, this is located under the hood of the car. Open the line, and you should see a small plastic tab that can be pulled out using tweezers or pliers. If it doesn’t want to budge, an orifice tube can be used to remove it from the device. This will grip onto the removal tabs and help you pull out the old tube.
2. Inserting The New Orifice Tube
Insert your new orifice tube into the line. Make sure that the tube is facing toward the evaporator. Usually, you’ll find an arrow pointing toward the evaporator. Use this as a guide. Seal the open line shut again using lubricated o-rings.
3. Reinserting The Refrigerant And Recharging The System
This final complicated step will most likely require professional equipment and help. It’s crucial that the correct amount of refrigerant is inserted, or the air conditioning system won’t work properly.
We recommend that you don’t attempt this process unless you’re very familiar with your car and understand how to identify the correct components of the air conditioning system easily. If you’ve managed to replace the orifice tube alone, congratulations! Your summer drives should now be much cooler and much more comfortable.
The air conditioning system in your car is complex. There are many components that contribute to its functionality, and when even one of these parts starts to malfunction due to age or breakage, the whole system can collapse. Identifying the error within the system is the first important step. With this guide, you’ll know what small signs you can look out for to determine which part of the system isn’t working properly.
A problem in the temperature of the air coming from your air conditioner is likely an issue with your expansion valve or orifice tube. This is because the orifice tube’s job is to regulate pressure, and therefore, the temperature of the refrigerant liquid and/or vapor. If the air coming out of the system is either too hot or too cold, this is probably your issue.
Replacing the orifice tube can be a complicated and challenging task, but if it’s something you feel comfortable and capable of doing, this guide has helped you through the four necessary steps. Hopefully, your car’s air conditioner is back in business, and you can breathe a little more easily.