The air pump is a common emission component found on many road vehicles, and particularly older vehicles with V8 engines. The air pumps serve to reduce emissions, and is usually driven by an engine accessory belt. As is normally the case with most automotive belts, they are made of rubber that will wear out and eventually need to be replaced.
As the air pump belt is what drives the pump, the pump, and therefore the entire air injection system, cannot function without it. Because the air pump is an emission component, any problems with it can quickly translate to problems with engine performance, and can even cause the vehicle to fail an emissions test. Usually, a careful inspection of the belt for any visible symptoms can quickly reveal to the driver if the belt needs to be replaced.
1. Cracks on the belt
Cracks on the belt are one of the first visual symptoms that the air pump belt needs to be replaced. Over time, with constant exposure to the extreme heat from the engine and contact with the pulleys, cracks will develop on and at the ribs of the belt. Cracks are permanent damage to the belt that weaken its structural integrity, making the belt more susceptible to failure.
2. Large chunks of rubber missing from belt
As the AC belt continues to wear, cracks can develop near each other and weaken the belt to point where entire chunks of rubber can break off. Any places along the ribs of the belt where rubber has broken off are considerably weakened, as are the places along the belt where it is more likely to break.
3. Scuffs along the outside of the belt
Another symptom of an excessively worn AC belt are scuffs along the edges or outsides of the belt. Usually this is caused by a misalignment of the belt on the pulley, or by contact with some sort of debris or component of the engine. Some scuffs may cause threads from the belt to come loose. Loose threads along the edges or outside surface of the belt are obvious signs that the belt should be replaced.
The belt is what directly drives the AC compressor, which pressurizes the entire system so that the AC can function. If the belt fails, your AC system will be completely disabled. If your AC belt has failed, or you suspect that it may need to be replaced, have a professional technician, such as one from YourMechanic, inspect the vehicle and replace your air pump belt to restore and maintain proper functionality of the vehicle’s AC system.
This article originally appeared on YourMechanic.com as Symptoms of a Bad or Failing Air Pump Belt and was authored by Ed Ruelas.