In an air brake system, the air governor controls the cut-out pressure range.

In an air brake system, the air governor controls the cut-out pressure range.

• A. 80-100 psi
• B. 70-90 psi
• C. 150-170 psi
• D. 120-130 psi

Answer: (D)

The air governor sets the high-pressure limit at which the compressor stops charging, known as the cut-out pressure. In most air brake systems, the cut-out occurs around 120–130 psi, so the governor’s specified range for stopping the compressor matches that band. This keeps system pressure within a safe, effective operating window. The other options correspond to lower pressures (often associated with the cut-in start pressure) or exceed typical maximums, so they don’t represent the cut-out setting.

The air governor sets the high-pressure limit at which the compressor stops charging, known as the cut-out pressure. In most air brake systems, the cut-out occurs around 120–130 psi, so the governor’s specified range for stopping the compressor matches that band. This keeps system pressure within a safe, effective operating window. The other options correspond to lower pressures (often associated with the cut-in start pressure) or exceed typical maximums, so they don’t represent the cut-out setting.