OM3050 7/09 Operating Instructions - Section 30 Page 30-21 FIGURE 30-3. PARKING BRAKE WIRING FOR TOWING 1. Switch 2. Ground Wire 3. Harness 8. If the truck is loaded, dump the entire load. Never pull or tow a loaded truck. Refer to “Disabled Truck Dumping Procedure”. 9. The parking brakes must be released before towing. To release the parking brake, follow the steps below to install a special wiring harness to release the parking brakes. a. Ensure switch (1, Figure 30-3) is in the OFF position. b. Connect one lead of the special wiring harness to the 24VDC bus bar terminal on the side wall in the auxiliary control cabinet for the 24V supply. c.
Disconnect the truck wiring harness from parking brake solenoid (2, Figure 30-4). Connect special wiring harness (3, Figure 30-3) to the parking brake solenoid. Attach the short lead (2) to ground. FIGURE 30-4. BRAKE CABINET 1. Brake Manifold 2. Park Brake Solenoid d. WIth the window lowered, place the end of the special wiring harness inside the cab so the operator can control the parking brake with switch (1).