How to Repair a Refrigerant Line

If your car is having issues with its refrigerant line, your first objective is to identify the source of the leak. Once the leak is identified, a course of action can be determined. If the leak is in a flexible rubber line, the line itself must be replaced. If the leak is in a connection, the leak can be repaired on the vehicle. If the leak is in a component such as the drier, condenser, evaporator or compressor, the unit would need to be replaced to facilitate a repair. In all cases, an air conditioning reclaimer is necessary to evacuate, vacuum, and charge the system.

Things You'll Need

• Air conditioning reclaimer as required by law
• Freon leak detector
• Set of line wrenches
• Set of wrenches
• Box of assorted air conditioning o-rings

Instructions

1. Locate a leak in a line with the use of the Freon leak detector. Turn the detector on and allow it to heat up for a few seconds. Move the detector slowly along all the air conditioning lines. Remember that Freon is heavier than air and will sink, so check the lines on the bottom. When a leak is found, the detector will give off a continuous audible signal.

2. Evacuate the system of all Freon before attempting to open the system. Open the valve on the tank in the rear of the reclaimer. Plug the reclaimer in and make sure both the low (blue) valve and the high (red) valve are turned off. Connect the blue line to the low-side Schraeder valve on the vehicle's air conditioning system. This is the largest-diameter line. Connect the red line to the remaining Schraeder valve, which will be the high side with all the high pressure. Open both valves of the reclaimer. Press the button marked "Reclaim" or "Evacuate." Allow the machine to operate until it stops and indicates an empty system on the pressure gauge with a reading of zero. Close both the red and blue valves and turn the machine off.

3. Remove the leaking line using two wrenches of appropriate size.

4. Clean the connection ends with a clean cloth. Remove the o-rings and replace them with new ones. Coat the o-rings with a small quantity of refrigerant oil, replace the hose, and tighten the connections.

5. Replace the hose with a new one if it was found leaking anywhere other than at the fittings. Before installing the hose, clean and install new o-rings as directed in step 4.

6. Turn the machine on and open both valves. Press the button marked "Vacuum." Allow the machine to operate for 30 minutes to draw down the system into a vacuum. If there are no further leaks the system should draw down to 30 inches of vacuum on the machine gauge. The red line below zero indicates a vacuum. After 30 minutes, close the valves, then turn the machine off. Watch the vacuum gauge for five minutes. If the system holds vacuum, the gauge will not move. If the vacuum decreases, a leak exists. Add two pounds of Freon and retest the system for leaks (with the leak detector). Once the repair is complete the process should be repeated until there is no vacuum loss.

7. Turn the machine on and open the valves. Press the button on the top of the machine located on the oil valve. Hold the button until the gauge shows four ounces of refrigerant oil has been injected to replace the oil lost from the leak.

8. Look on the radiator support or hood for a placard indicating the quantity of charge the air conditioning system holds. With the machine on, press the button marked "Charge." It will ask how much charge. Punch in the amount on the number board. Now press "Enter," followed by the charge button again. The system will stop charging once the correct amount is injected. Turn both valves on the lines off. Turn off the valve on the tank in the rear. Turn the machine off and disconnect the two lines on the vehicle. Replace the Schraeder valve caps.