Testing for Air Conditioning System Leaks

Of course, everyone would want to know the source of the leak before deciding to replace the low-pressure hose on an air conditioner. Most AC leaks come from the condenser, the dryer, the evaporator, and AC compressor seals. AC units come with multiple low-pressure hoses that connect the compressor to the evaporator and expansion valve.

The source of the leak could be any of those connections, components, or hoses. That is what makes the process of diagnosing an AC unit time-consuming and complicated even for the experienced repair technicians. However, there is a simple guide that even a novice person can follow to diagnose a leaking air conditioning system in Modesto, California or any other location.

Locate all the Lower Ports of the Air Conditioner

Most SUVs and trucks come with a Schrader valve mounted to the refrigerant can and port for charging the AC unit. For the test to complete, the mechanic has to locate the AC low port and remove any available cap. Then attach the valve to the lower side port and snap that connection tightly. Chances are the lower side port has defects if the link cannot lock into place. It could also indicate that the lower side port is the source of the leak.

Turn on the Air Conditioner and Activate the Canister

Turn the air conditioner on after securing the refrigerant to the valve, but allow it to heat up for about two to three minutes. Let it run until it achieves the maximum pressure setting and cold setting. It should run for at least two minutes before you move the refrigerant valve to the open position.

Add Dye to the Air Conditioner after Activating the Canister

Back of air condition unit

Attach a pressure gauge to the Schrader valve to display the refrigerant pressure. Most indicators come with a green section that indicates the pressure to add to the air conditioning unit. With the refrigerant can upside down, turn the canister on until the desired pressure is achieved. The can comes with instructions that guide users on how to check if the AC unit is fully charged. But most certified mechanics prefer running the AC compressor for about two to three minutes and then listen to it to engage the AC system.

The best way to test for dye and leak on an AC unit is in the dark. Though this may sound crazy, the dye and UV light often show up well when it is dark. The trick is to test for leaks with a little flashlight.

The presence of dye indicates that the AC unit is leaking, but repair technicians can use a drop light to illuminate the leaking section. Experts recommend replacing the AC hose if the component that is leaking is connected to the low-pressure hose. Alternatively, follow the instructions in the manufacturer’s manual for replacing parts of the AC if the leak is coming from another component. Shining a UV light or black light along all connections or lines of the AC unit can help detect leaks on other parts.

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