Chevrolet Low Cab Forward 2023 Manual page 213

212 Vehicle Care
Brake Air Pressure
1. Check the brake air pressure gauges to
see that the primary and secondary air
systems are charged with air to proper
pressures.
2. Confirm the parking brake is fully
engaged. There are two air tanks on
your vehicle. One is behind the rear axle
and the other is between the front and
rear axles. Pull the lanyard attached to
the drain tap at the bottom of each air
tank. Allow the air in each tank to be
dischared.
Brake Air Pressure Warning Light
3. Start and run the engine at idle. The
brake air systems are in order if the
brake air pressure increases to the
typical air brake pressure shown above,
the Air Dryer discharge valve opens and
the brake air pressure warning light
goes out.
The amount of time before the brake air
pressure warning light goes out may vary
depending on the temperature and other
environmental conditions. However, you
should contact the nearest dealer if air
pressure does not increase at all or the
brake air pressure gauges show different
pressures after the Air Dryer discharge valve
opens.