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2 Key Components in an Air Brake System

Air Brake System
Most trucks, buses, and 18-wheelers on the road today generate their stopping power by means of air brake systems. Air brakes offer an efficient and highly safe means of stopping. Better yet, an air brake system allows secondary vehicular units like trailers to enjoy the exact same braking power as the cab.

Of course, despite their general reliability, air brake systems may develop problems as time goes on. Unfortunately, many truck owners fail to recognize such issues due to unfamiliarity with the working of an air brake system. This article takes a closer look at two key components of an air brake system, as well as some common problems they experience.

1. Air Compressor

As its name clearly states, an air brake system utilizes the power of air - in other words, pneumatic power - in order to provide the force necessary to stop a vehicle. Of course, the air in question must be highly pressurized in order to generate the appropriate amount of force. This pressurization occurs in the subset of the air brake system known as the charging system.
At the heart of the charging system lies an air compressor, which forces increasing amounts of air into a storage reservoir until the requisite pressure has been achieved. The air compressor receives its power directly from the truck's engine, either through a series of gears, or through a special belt. Likewise, the compressor also shares the truck's cooling system in order to keep temperatures within an acceptable range. 
Perhaps the most common problem associated with the air compressor involves either a delay or an outright inability to build air pressure. This issue may occur as the result of various compressor problems, most of which involve component failure. For instance, failed compressor drives, air governors, and head gaskets may all make it difficult to achieve full pressure.

2. Reservoir

As noted above, the compressor pushes air into a special tank known as the reservoir, gradually building up to the necessary pressure level. The reservoir functions in a passive manner, simply acting to hold the compressed air until the appropriate time. Nonetheless, reservoirs may experience problems that compromise the functionality of the system as a whole.
Air reservoirs face an especially potent foe in the form of moisture and water. If allowed to remain long enough inside of a reservoir, such moisture will quickly lead to corrosion. Ultimately, this may cause the walls of the reservoir to fail, allowing air to escape long before it reaches the pressure necessary for safe braking.
To reduce the threat of water, most air brake systems contain a component known as an air dryer, found between the compressor and the reservoir. The air dryer acts to remove both water and oil from the air before it reaches the reservoir. Yet once the dryer reaches its maximum capacity, it may no longer be able to prevent moisture from entering the reservoir.
For this reason, many reservoirs contain automatic drain valves. These valves open up at regular intervals, allowing any accumulate water to drain out the bottom of the tank.
The other major problem experienced by reservoirs involves leaking valves. A leaky valve allows air to escape from the tank at inappropriate times. As a result, the compressor must work much harder than it should to provide make-up air to the reservoir. Leaky valves may also reduce the effectiveness of your brakes, especially during periods of intensive braking.
Valve leaks may stem from a number of causes, depending on which particular valve has been affected. For more information on what it takes to troubleshoot and repair common air brake problems, please don't hesitate to contact the truck experts at S & T Truck Repair.