The body hoist system has two modes that will not allow the ECM to follow the requests of the operator.
The body hoist system will be forced into hold under ANY of the following six conditions.
- After power is applied to the ECM the body hoist system will be forced into hold during the first two seconds.
- After the engine starts the body hoist system will be forced into hold for the first two seconds.
- After the start relay has been energized the body hoist system will be forced into hold for the first two seconds.
- The body hoist system will be forced into hold if the ECM records an active fault with the hoist lever.
- The body hoist system does not respond when any combination of faults with the solenoids has occurred and the body hoist system fails to respond to any requests from the operator.
Note: This is an example. If the raise solenoid is shorted to the +battery circuit, then the ECM will activate the lower solenoid. This is done in order to keep the bed from moving. At the same time, the override would be activated . This will stop the bed from moving after the diagnostic code is removed. When the solenoid has an open circuit condition the ECM will activate the override. This is another example. If the solenoid has an open circuit condition and the hoist lever is in the RAISE position, then the ECM will activate the override.
- The body hoist system will be forced into hold if the engine is not running AND the operator is not trying to lower the bed with a dead engine.
If none of the above conditions are true, the override will stay active until the hoist lever is placed in the hold position or the hoist lever moves through the hold position.
Note: The truck will start when the body is in the raised position and the hoist lever is in the FLOAT position. Before the body will lower, the hoist lever is moved into the HOLD position before the lever is moved into the FLOAT position.
Lowering the Bed with a Dead Engine
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Be sure all personnel are clear of equipment while equipment is being lowered. Failure to stay clear may result in personal injury. |
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| Required Parts | |||
| Item | Part Number | Part Name | Qty |
| 5 | 6V-3965 | Fitting | 1 |
| 3J-1907 | O-Ring Seal | 1 | |
| 6V-0852 | Dust Cap | 1 | |
| 6 | 5P-6944 | Straight Thread Adapter | 1 |
| 3K-0360 | O-Ring Seal | 1 | |
| 8 | 1U-5754 | Hose As | 1 |
| 9 | 6V-4143 | Coupler | 2 |
If a fault has occurred on the machine and the engine has stopped, the dump body may need to be lowered.
Note: Make an assessment of the location of the machine and of the ground conditions. if the machine may become unstable, carefully move the machine to a level surface before you lower the body. Refer to Operation and Maintenance Manual, "Towing the Machine" for more information.
Note: The batteries for the machine must be fully charged in order to perform this procedure.
- Move the parking brake control to the ENGAGED position. Install the steering frame lock. Block the wheels.
Refer to Operation and Maintenance Manual, "Steering Frame Lock".
- Carefully loosen the cap on the hydraulic tank. This will relieve any pressure in the hoist system.
- Loosen nut (1) . Insert a 3/8 hex wrench into valve (2) . Turn the valve counterclockwise until the valve contacts the stop.
Note: If the body is not overcenter, then step 3 may be sufficient enough for the body to lower to the frame. In that case, once the body has lowered completely, go to step 13. If the body will not lower, then the remaining steps must be performed.
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| Illustration 1 | g01024267 |
- Locate fitting (3) on the manifold.
Note: Machines with the following serial numbers are not equipped with fitting (3) from the factory: (S/N: AFX571-723AGF568-701) Perform the following steps in order to install the fitting.
- If the body is not overcenter, block the body in position. If the body is not blocked, the body may lower when plug (4) is removed and oil will be spilled on the ground.
Show/hide table
Illustration 3 g01024305
- Slowly remove plug (4) from the manifold and replace the plug with items (5) and (6) . When the plug is removed, catch any oil that is spilled in a suitable container. If the body is overcenter, oil loss should be small. If the body has been blocked, oil loss should be small.
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| Illustration 2 | g01026585 |
- Locate test port (7) for the secondary steering.
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| Illustration 4 | g01024482 |
- Install items (8) and (9) between test port (7) and fitting (3) .
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| Illustration 5 | g01024483 |
- Tighten the cap on the hydraulic tank.
- Turn the engine start switch to the ON position.
- Press the switch for the secondary steering. Turn the steering wheel to the RIGHT (against the steering frame lock). Hold the switch for 30 seconds. Release the switch. Wait for at least 3 minutes. This will allow the battery to recover.
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| Illustration 6 | g00948641 |
(S/N: AFX1-1097AGF1-1010) | |
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| Illustration 7 | g01035886 |
(S/N: AFX1098-UPAGF1011-UP) | |
- Repeat step 9 until the body begins to lower under the body's own weight.
- When the body is completely lowered, turn the engine start switch to the OFF position.
- Remove the hose.
- Turn valve (2) clockwise until the valve is closed. Tighten nut (1) to a torque of 50 ± 7 N·m (37 ± 5 lb ft).