BOLT, HEX E190048 - Caterpillar

Sudden movement of the machine or release of air under pressure can cause injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the air system and brakes.
Operational checks of the air system and of the brakes can be used to find the source of leakage in the system. Also, operational checks can make a diagnosis of poor performance.Note: You can hear the sound of air leakage. Air leakage can be seen when soapy water is applied to connections, valves and hoses.
Start the engine and allow the air pressure to increase to the cut out pressure. Stop the engine.
Check the air control valve for the parking brake in the console to the right of the operator's seat.
Check air lines and fittings at the junction blocks. The junction blocks are located at the top of the tandem housings.
Check all the valves on the air tank.
Check for leakage in the hoses and the connections from the air compressor and the air compressor governor to the air tank.
Check for leakage in hoses, lines, connections, and components from the air tank to the air control valve for the service brakes.
Check for leakage in the air control valve for the service brakes.
Depress the service brake control (pedal) and hold the service brake control (pedal) down. Check for leakage in hoses, in air lines and in connections from the air control valve for the service brakes to the service brakes. Release the pedal.
Check for leakage in the quick-release valve and the parking brake actuator. Place the transmission control (lever) to the PARKING BRAKE ENGAGED position.
Make sure that the centershift lock switch is in the ENGAGED position. Check for leakage in hoses, lines, connections, and components from the air control valve for the service brakes to the port on the centershift lock pin.
Make sure that the centershift lock switch is in the DISENGAGED position. Check for leakage in hoses, lines, connections, and components from the air control valve for the service brakes to the port on the centershift lock pin.
Push down and pull back on the transmission control (lever) to the NEUTRAL position. Check for leakage in the hose and in the connections from the air control valve for the parking brake to the parking brake.Note: If the air pressure in the air tank lowers to the cut-in pressure, start the engine and operate the engine. When the air pressure reaches the cut out pressure, stop the engine.Note: When you check the control valves for leakage, check the exhaust passages for any restrictions such as mud or dirt. Restrictions in an exhaust passage of the control valves may prevent the release of air pressure during normal operation. Also, restrictions may slow the release of air pressure during normal operation.