In-car air conditioning is one of the great miracles of convenience when the system is working. Then there are times where it’s not working, and you feel like a chump for paying for a car with a nice & cozy interior only to have it turned into an oven on 4 wheels. Today on ShopTalk, we aren’t just talking about what makes that AC work; we’re going to go over some of the basics when it comes to repairing and recharging your car’s A/C system.

Lo primero es lo primero: ¿Cómo funcionan estas cosas?

I’m about to blow you away, literally: air conditioning systems do NOT create cold air. What they do is remove the heat and moisture from the air already in your car, leaving cooler air behind.

Freon/refrigerant resides in the a/c system. Then you have the a/c compressor, which initiates the high side of the system and compresses the freon/refrigerant to high pressure, causing it to liquefy and travel through high-pressure lines to the condenser. What a condenser is, is akin to a radiator, and it puts the liquid in contact with fresh air on the outside of the vehicle, which absorbs the heat from the liquid.

After flowing into the expansion valve or orifice tube, where it is restricted and becomes gaseous, into the low-pressure side of the a/c system, it flows into the receiver dryer/accumulator that contains a desiccant bag to remove and collect unwanted moisture/water and impurities.

The clean, gaseous freon/refrigerant then travels through a series of tubes into an evaporator (located in the passenger compartment of the dash). This allows the freon/refrigerant, in a gaseous state, to absorb heat from the air passing through the evaporator fins, leaving behind cooler air. The fans in your car blow this cooler’s dry air into the cabin before it circulates, and the process starts over.

Entonces, ¿cómo se repara y mantiene un sistema de aire acondicionado?

The key is in the freon/refrigerant. That has to stay fully charged in order to ensure proper operation.  If the freon/refrigerant level ever gets too low, the a/c system will still be able to operate, but the cooling effect will be diminished, not to mention the shorter operation cycle and the damage that will occur to the whole system.

Always be sure to check the pressures of the a/c system while in use. This will give you an indication of low freon/refrigerant, even if this does not tell you how low the refrigerant actually is. When it is low, it is usually due to a leak in the system.

Now, if you think your a/c system is not working properly, the best thing to do is to take it to a shop that you trust. They will perform some basic checks on the following

• Funcionamiento del compresor
• Embrague y correa del compresor
• Las presiones altas y bajas del sistema durante el funcionamiento,
• Funcionamiento correcto del panel de control
• El ventilador del calentador
• Funcionamiento del ventilador de refrigeración del motor
• Restricciones en el sistema
• Flujo de aire adecuado a través del condensador y el evaporador.
• Any obvious leaks

Now, it is possible to recharge your AC yourself, even as we recommend going to a trusted repair facility.

PASO 1: Determine si todavía queda refrigerante en su sistema.

What you do is fit a charging hose on the low-pressure port, located on the refrigerant line on your car, and near the accumulator. USE EYE PROTECTION.

PASO 2: Verifique si hay fugas evidentes.

If your system is lacking the proper amount of refrigerant, you have a leak. The good news is that it takes months to deplete the refrigerant. Do keep in mind that recharging a leaking system is a pointless exercise in futility. You can check these easily by spraying a soapy water solution on fittings and watching for bubbles to appear.

STEP 3: Make sure the condensing coils are not obstructed; the compressor is operating.

Puedes probar un compresor con baja carga haciendo saltar el interruptor de presión en el acumulador.

PASO 4: Golpee y selle la lata de refrigerante.

Completely open the valve on the tapping fitting, thereby retracting the tapping pin into the valve body. If you don’t do this, it will lead to a puncture and failure. After securely threading the tapping valve on the refrigerant can, make sure to close the valve completely. This prevents unwanted leaks.

Side note: Be sure to purge the charging hose beforehand, and locate the low-pressure charging port on the refrigerant line on your car (the larger tube, near or on the accumulator).

PASO 5: Encienda el motor y encienda el aire acondicionado en temperatura alta, con ventilador en alta potencia.

Most recharging hoses come equipped with a pressure gauge, which lets you check the system to determine whether it needs refrigerant. Now, if the pressure is holding steady, congratulations: the system is full and should not be charged, good job, and close up shop. Now, if the pressure is below the recommended range and/or falling, continue following our instructions to recharge the system.

PASO 6: Abra la válvula hasta que escuche el refrigerante pasando por la manguera.

Let the can dispense its contents (2-5 minutes most of the time). Be sure to keep the can with the tap up at all times in order to allow non-liquid refrigerant into the suction side of the system and prevent compressor damage. WARNING: Do not overcharge!

PASO 7: Cierra todo.

When you are finished charging, close the valve and disconnect the hose when the can is either empty and/or no longer discharging. Once again, inspect for port leaks before replacing all the caps.

PASO FINAL: Probar todo.

Finally, you will check the air from the car’s AC vents. If everything is working properly it should be blowing cold (38-45 degrees), if not, it is possible that either one can of refrigerant was not sufficient to charge the system, or some other component was the problem. Once again: Do not overcharge!

Si el problema persiste, lleva tu coche a un taller lo antes posible.