OM3040 03/13 Operating Instructions - Section 30 Page 30-15 Lowering the Body 9. After the load has been emptied from the body, release the hoist control lever. The body of the disabled truck should immediately begin floating downward. If any residual material left in the body prevents lowering, perform the following: a. Place the good truck hoist lever in the POWER UP position, and monitor the body of the disabled truck for downward move- ment. The body of the good truck may rise a small amount during this step. b. Once the body of the disabled truck begins downward, move the hoist control all the way forward, and then release. The lever should then be in the FLOAT position. 10.
Shut off the engine. Bleed pressure from the brake accumulators, steering accumulators, and the hydraulic tanks on each truck. FIGURE 30-4. POWER DOWN RELIEF VALVE 1. Power Down Relief 2. Hoist Pilot Valve 11. Disconnect the hoses from each truck. 8. Place the hoist control in the POWER DOWN position, and continue to hold in this position until the hoist cylinders reach full extension. Increase engine speed as necessary. 12. Re-adjust the relief valve setting on the good truck. (Turn the screw counter-clockwise the same number of turns as was noted earlier in this procedure.) The power down relief valve on a HD1500-5 machine should be set at 10 342 kPa (1500 psi).
Do Not move the hoist control from the POWER DOWN position until full extension is reached. Do Not attempt to move the lever to the HOLD position during this procedure. FIGURE 30-5. HOIST CIRCUIT QUICK DISCONNECT FITTINGS 1. Power Down Circuit 2. Power Up Circuit