This module discusses the features and operation of the air system and the brakes. The following Motor Graders are covered in this module:
The air system and the brakes have the following main components:
- Monitoring System
- Air Compressor
- Air Dryer
- Relief Valve for the Air Tank
- Air Horn
- Air Control Valve for the Service Brakes
- Air Control Valve for the Parking Brake
- Service Brakes
- Parking Brake
The AVSpare Monitoring System consists of an action alarm, action light and a monitoring panel with individual alert indicators for each machine system. The AVSpare Monitoring System provides three warning categories. The first warning category requires only operator awareness. The second warning category needs operator response. The third warning category requires immediate shutdown of the machine systems.
The air compressor pressurizes the air for the air system and the brakes. The air compressor operates only when the engine is running. An air governor regulates the air pressure in the air system and the brakes.
The air dryer removes moisture and oil from the compressed air. Clean, dry air is very important for safe operation and safe performance of the brake system. Clean, dry air will also prevent corrosion of parts.
Relief Valve (Air Tank)
An air relief valve is attached to the center section of the air tank. If the air compressor governor does not work correctly, the air pressure in the air tank may increase and the air system may be damaged. The air relief valve will open in order to prevent damage to the air system.
The air horn switch is located in the center of the steering wheel. Pressure air for the air horn is supplied through the air control valve for the service brakes.
Air Control Valve (Service Brakes)
The air control valve for the service brakes provides the proper flow in order to engage the service brakes. The air control valve for the service brakes also balances the air pressure between the left side brakes and the right side brakes.
Air Control Valve (Parking Brake)
The air control valve for the parking brake allows air pressure to the parking brake in order to disengage the parking brake. When the air control valve for the parking brake closes, the parking brake springs are allowed to engage the parking brake.
The service brakes are actuated by pressure air from the air control valve for the service brakes. The service brakes are activated when the brake control lever is depressed.
The parking brake engages when the transmission control lever is in PARK. The parking brake is spring engaged. Air pressure disengages the parking brake.