Operating Instructions - Section 32 10/04 OM3215 Page 32-14 Blank (Not Used In This Application) Reserved for future options (11, Figure 32-8). Wheel Brake Lock Control The Wheel Brake Lock control (12, Figure 32-8) should be used with engine running for dumping and loading oper- ations only. The brake lock switch actuates the hydraulic brake system which locks the rear wheel service brakes only. When pulling into shovel or dump area, stop the truck using the foot-operated service brake pedal. When truck is completely stopped and in loading position, apply the brake lock by pressing the rocker switch toward the ON symbol. To release, press the rocker switch toward the OFF symbol.
Use at shovel and dump only to hold truck in position. Do not use this switch to stop truck, unless foot-operated treadle valve is inoperative. Use of this switch applies rear service brakes with unmodulated pressure! Do not use brake lock for parking. With engine stopped, hydraulic pressure will bleed down, allowing brakes to release! Parking Brake Control The Parking Brake is spring applied and hydraulically released. It is designed to hold a sta- tionary truck when the engine is shutdown and keyswitch is turned OFF. The truck must be completely stopped before applying the parking brake, or damage may occur to parking brake.
To apply the parking brake, press the rocker switch (13, Figure 32-8) toward the ON symbol. To release the parking brake, press the rocker switch toward the OFF symbol. When the keyswitch is ON and Parking Brake switch is applied, the Parking Brake indicator light (A3, Overhead Panel) will be illuminated. Do not use the parking brake at shovel or dump. With keyswitch ON and engine running, sudden shock caused by loading or dump- ing could cause the system's motion sensor to RELEASE the park brake. Tachometer The tachometer (14, Figure 32-8) registers engine crankshaft speed in hundreds of revolutions per minute (RPM). Governed RPM: Komatsu SDA16V160 or SSDA16V160 Engine:
Low Idle — 750 RPM High Idle, No load — 1910 RPM High Idle, Full Load — 1900 RPM