You see refrigerant building up on the hose. The low side is designed to carry the refrigerant to the compressor, so if there is a problem with the hose, it tends to negatively impact the entire AC system. When the low pressure hose has a leak, the first and most obvious sign is there will be less cool air flowing into the cabin. There is a lack of cool air blowing into the cabin. When the low pressure hose has a leak or is broken, it tends to display the following symptoms or warning signs. If the problem is with the high pressure hose, the symptoms will be not as noticeable at first.īecause the AC system on your vehicle is closed loop, it's critical for you to find the source of the leak, before making decisions on replacing parts. When the leak is on the low pressure side, this means that the cabin is going to get less cool air. This is due to the fact that the low pressure side is where the cool air is blown into the vehicle. When the low pressure side of the air conditioning system is damaged, symptoms tend to be noticed sooner than if the issue is on the high pressure side. Part 1 of 4: Understanding the symptoms of a broken AC low pressure hose If this occurs, you'll have to test the AC system for leaks to determine the precise location that is causing the AC system failure and replace those parts in order for the air conditioning in your vehicle to work smooth and correctly. Due to the fact that the engine compartment is extremely hot, the AC low pressure hose can sometimes develop small holes that causes refrigerant to leak and can render the AC system useless. Most low pressure AC hoses are made out of metal, with flexible rubber hose material for places where the hose needs to run through tight spots inside the engine compartment. Both systems must work together to convert warm air inside your cabin to cool air that is blown into the cabin after completing the closed-loop cycle. The high pressure side distributes liquid refrigerant through the AC condenser and dryer. It's referred to as the low pressure side because during this phase of the cooling process, the refrigerant flowing through the system is a gaseous state. The low pressure side of the air conditioning system in most vehicles is attached from the AC evaporator to the AC compressor. However, occasionally problems occur with the AC low pressure hose which requires replacement, and recharging your AC system. When the lines are secure and tight, there is no reason why the AC in your vehicle shouldn't continue to blow cool air unless the refrigerant needs to be added. Typically, the leaks are found in one of two different locations the high pressure or AC feed lines or the low pressure or return lines. The air conditioning (AC) system of today's modern cars, trucks, and SUVs is a closed-loop system, meaning that coolant and refrigerant inside the system does not escape unless there is a leak.