Maintenance 119 Front and Rear Brake System Air Pressure Air pressure in the two circuits is monitored by two pressure gauges on the right side of the instrument panel. The gauge for the secondary (front) brake circuit is marked with an “F” within a symbol and The gauge for the primary (rear) brake circuit is marked with an “R” within a symbol. The two pointers should register equal or nearly equal pressure. By observing the gauge pointers, the operator is forewarned in the event of a pressure drop in either or both of the circuits, and also may readily identify the specific circuit. Gauge 1 Before operating the vehicle, check the air gauges which indicate air pressure.
The LED lights up if the air pressure drops below 65 psi. DO NOT operate the vehicle in this condition of air pressure being below 65 psi. Gauge 2 Air Tubing and Hoses All compressed air tubing and hoses need regular inspection. Check for signs of wear and that the routing is not near parts that can cause damage. Have any damaged tubing or hoses replaced by your local Volvo Truck dealer. W3005381