The supply pressure gauge indicates the pressure in which part of the system?

The supply pressure gauge indicates the pressure in which part of the system?

• A. The air tanks
• B. The tires
• C. The hydraulic reservoir
• D. The air lines

Answer: (A)

In an air brake system, the supply pressure gauge shows the pressure in the air tanks (air reservoirs) that store compressed air for the brakes. It doesn’t measure tire pressure or hydraulic fluid; those are separate systems or components. The air lines carry air to the brake chambers, but the gauge labeled supply specifically reflects how much stored air is available in the tanks. Keeping this pressure within safe ranges is essential for reliable braking, and a drop can indicate leaks or other issues that require attention.

In an air brake system, the supply pressure gauge shows the pressure in the air tanks (air reservoirs) that store compressed air for the brakes. It doesn’t measure tire pressure or hydraulic fluid; those are separate systems or components. The air lines carry air to the brake chambers, but the gauge labeled supply specifically reflects how much stored air is available in the tanks. Keeping this pressure within safe ranges is essential for reliable braking, and a drop can indicate leaks or other issues that require attention.