One of the many parts that can fail within your vehicle's air conditioning, is the orifice tube. This tube is also known as the expansion tube, and is located within the tube between the condenser and the evaporator. It has 1 side that is a little smaller than the other, to supply more pressure. There is also a screen on the inside, to catch any debris that may be traveling in the system. When this orifice tube does not work properly, the air conditioner will seem like it is seized up. Here are some steps to replace the orifice tube in your vehicle.
Step 1: Become Familiar with AC Unit
Before jumping under the hood of your vehicle, and tearing apart the various tubes looking for the orifice tube, you should become familiar with the air conditioning. Read through a current repair manual for your vehicle, and pay particular attention to the air conditioning section. This will help you to see all of the different parts and components that make up your car's AC.
Handling refrigerant is Federally restricted to licensed handlers, so be aware that you will need to involve a licensed professional in this repair.
Step 2: Locate Orifice Tube
The orifice tube is located in a junction, in a tube that runs between the condenser and the evaporator.
Step 3: Disconnect Tube from Orifice Tube
Use an open ended wrench, or a coupling wrench, and loosen up the coupling in the liquid line. This connection will be on the upper end of the junction box.
Step 4: Remove Seal from Line
Located within the line, you will find a small rubber seal. This must be removed before you can take out the orifice tube. It is located on the end of the liquid line coupling, and can be removed with a screwdriver or a pair of needle nose pliers.
Step 5: Remove Orifice Tube
You will see the orifice tube within the line. Use some pliers, and gently pry the tube out of the line. You may need to twist in back and forth, in order to work it free. Make sure that you do this carefully, so it does not break off within the tube.
Step 6: Install New Orifice Tube
Once the old orifice tube is removed from the liquid line, you can install the new one. Place it in the same orientation as the old one. The smaller section should be pointed away from the coupling. Slide it into the tube, and make sure it is seated properly.
Step 7: Install Seal
Before making the connection with the coupling, you must place a new seal over the pin. Do not reuse the old one. Carefully press it into place, and connect the coupling to the line. Tighten the nut with a wrench.
Step 8: Charge the System
Once the line is secure again, you need to charge the air conditioning system. This is something that must be done at a shop, so there will be some expense included with the replacement. Turn on the air conditioner, and you should find that the new orifice tube is allowing better airflow.