Operation - Section 3 OM3017.3 Page 3-24 Instrument Panel and Indicator Lights (36, Figure 3-7) DRY ROAD / SLIPPERY ROAD SWITCH RETARD SPEED CONTROLS (RSC) (38, 39, & 40, Figure 3-7) The Dry / Slippery road control switch permits the operator to select either full braking capability at all wheels for "dry" road or reduced braking at the front wheels for "slippery" road. Indicator (38) and controls (39, 40) are used to moni- tor and control the Retard Speed Control (RSC). Slippery road position reduces front wheel braking effort while maintaining full braking of the rear wheels.
Reduced braking of the front wheels as- sists in steering control on slippery roads, but increases stopping distance. (38, Figure 3-7) RETARD SPEED CONTROL INDICATOR The amber light is illuminated when the RSC switch (39) is pulled out to the "On" position. (39, Figure 3-7) RETARD SPEED CONTROL (RSC) SWITCH The retard speed control switch turns system "on" or "off". Pull out to turn "on", push in to turn "off". See instructions at beginning of this section for symbols. (37, Figure 3-7) WHEEL BRAKE LOCK (40, Figure 3-7) RSC ADJUST DIAL The Wheel Brake Lock should be used (with engine running) ONLY at the dump and loading operations.
When pulling into shovel or dump area, stop the truck using the service brake pedal. When truck is com- pletely stopped and in position (brake lock will not function if truck is moving above 2 MPH), apply brake lock by moving switch lever to "ON". This control ap- plies brake pressure to the REAR WHEEL BRAKES ONLY. Front wheel brakes are NOT applied. The RSC Adjust Dial allows operator to adjust safe productive downhill retarding speed of truck. When Dial is rotated counterclock- wise toward this symbol, RSC is set for slower speeds. When Dial is rotated clockwise to- ward this symbol, RSC is set for faster speeds. DO NOT use brake lock for parking!
Use of the brake lock with the engine shut down will allow the brakes to release! The throttle pedal position will override RSC setting. If operator depresses throttle pedal to increase truck speed, Dynamic Retarding will not come on unless truck overspeed setting is reached or foot operated retard pedal is used. When throttle pedal is released and RSC switch is "On", Dynamic Retarding will come on at the RSC pre-selected speed and will maintain that maximum speed.