Your car's air conditioning relies on varying pressures in order to produce the cool air you desire. This system depends on hoses delivering the refrigerant to the other components at the right pressure and temperature. Your car has two of these hoses on each "side" of the system: one for the high-pressure side and one for the low-pressure side. However, when one or both of those hoses fail, then your air conditioning system won't work efficiently. Here are some symptoms and causes of pressure hose failures.
The overall symptoms of failure are basically the same for both the high-pressure and low-pressure hoses. One of the more common symptoms is that your air will not be cool or will slowly lose its ability to cool over time depending on how big the problem is. Many components can cause this symptom, but hoses should be one of the first thing you suspect, and one of the easiest things to check when the problem becomes apparent. If your high-pressure hose is failing, then you may also see dripping or an oily stain on or around the hose or fittings as refrigerant is pushed or lost from the usually closed system.
Reasons for hose failure:
Many air conditioning hose failures are caused by leaks. High-pressure hose failure can also be caused by overfilling the system or crimping the hose. When these things happen, it creates a much higher than normal pressure which could cause the hose to explode or become detached. A clogged system can also create this same ultra-high pressure. Leaks can be caused by an actual cut or tear in the hose or by the hose breaking down from the inside out. Sometimes, hoses are cut when they rub against other components, such as against a belt or bracket, due to being misaligned or improperly installed. Hoses can also leak around the fittings which may be more difficult to find as they are frequently small or hard to see.
Fixing the hoses:
The good thing is that a hose problem can easily be remedied by anyone who knows how to work with an automotive air conditioning system. Hoses are fairly easy to find for most vehicles, and they are also easily removed and installed. Don't try to patch up any leaks as they often don't hold due to pressurized nature of the system, and even if you could, they wouldn't last very long. When you install the new hoses, make sure to protect them against rubbing against any other components. This may mean installing specialized brackets and ties to reduce movement.
For more information on fixing your car's AC, check out companies like Williams Oil Filter Service Co.