Operator Cab And Controls - Section 32 8/11 OM3232 Page 32-4 GRADE/SPEED RETARD CHART Grade/speed retard chart (8, Figure 32-1 and shown below) provides the recommended MAXIMUM retarding limits at various truck speeds and grades with a fully loaded truck. The operator should reference this chart before descending any grade with a loaded truck. Proper use of dynamic retarding will maintain a safe speed. OVERHEAD PANEL COMPONENTS The components described below are located on the overhead panel. Refer to Figure 32-1. Speakers Two speakers (9) for the radio/cassette player are located at the far left and right of the overhead panel. Two additional speakers are located in the rear of the cab.
Warning Alarm (Sonalarm) Do not LIGHTLY apply the service brakes when attempting to slow the truck on a downhill grade. Overheating of the brakes will result. FULLY apply the brakes (within safe limits for road conditions) in order to quickly slow the truck to maximum retarding limits or less. Warning alarm (10) will sound when activated by any one of several truck functions. Refer to Instrument Panel and Indicator Lights in this section for a detailed description of functions and indicators that will activate this alarm.
Radio/CD Player The numbers on the chart indicate the combination of speeds and grades which the vehicle can safely negotiate for unlimited time or distance during retarding. DO NOT exceed these recommended MAXIMUM speeds when descending grades with a loaded truck. This panel will normally contain radio/CD player (11). Refer to Section 70 for a complete description of the radio/CD player and its functions. Individual customers may use this area for other purposes, such as a two-way communications radio. NOTE: The decal in the truck may differ from the decal below due to optional truck equipment such as: wheel motor drive train ratios, retarder grids, tire sizes, etc.
Always refer to the decal in the operator's cab and follow these recommendations for truck operation. Air Cleaner Restriction Gauges Air cleaner restriction gauges (12) provide a continuous reading of the maximum air cleaner restriction reached during operation. The air cleaner(s) should be serviced when the gauge(s) shows the maximum recommended restriction of 25 inches of H 2 O vacuum. NOTE: After service, push the reset button on face of gauge to allow the gauge to return to zero.