A small air leak may seem minor, but on a truck equipped with air brakes, it can quickly become a serious problem. The system must maintain enough pressure to operate properly, so any constant air loss should be investigated before you continue driving.

One of the first wa
ing signs is hearing air escaping while the truck is stopped. You should also pay attention if the air compressor cycles too often, if pressure takes longer than usual to build back up, or if the gauge starts dropping while you apply the brakes. FMCSA wa
s that frequent compressor cycling often points to air loss somewhere in the system.

Leaks can develop in hoses, fittings, valves, brake chambers or even the air tanks. Wear, corrosion, heat and constant vibration can damage these components over time.

Do not ignore the problem assuming the compressor will always make up for the loss. During a commercial vehicle inspection, an air leak can be recorded as a violation and, depending on its severity or whether the vehicle fails the air-loss test, it can result in an out-of-service condition.

Before starting your day, listen for possible leaks, watch the air-pressure gauges and visually inspect accessible hoses and fittings. If the low-air wa
ing comes on or you notice excessive pressure loss, pull over in a safe location and do not continue until the cause has been identified.

The air system may give you little wa
ing beyond a light on the dash. Often, the first sign is a simple “ssss” sound that seems insignificant. Catching it early can help prevent a major repair, a failed inspection or getting stranded on the side of the road.