Steering Time
The steering time should be checked with the machine on a hard dry surface. The hydraulic oil must be at normal operating temperature. The dump body must be empty and the brakes must be disengaged.
- Start the engine and run the engine at high idle.
- Fully articulate the machine into one of the stops and release the steering wheel.
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Personal injury or death can result from sudden machine movement. Personnel can be injured during the steering check. To help prevent possible personal injury, keep all personnel away from the machine or in clear view of the operator when the machine is in operation during steering checks. |
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- Fully articulate the machine into the other stop. Begin timing when you start turning the steering wheel.
- Repeat this procedure several times in order to obtain an average time.
The steering time and the number of turns of the steering wheel will vary depending on the speed of the steering wheel. If you turn the steering wheel faster, the steering time will be faster and the number of turns of the steering wheel will be lower. If you turn the steering wheel slowly, the steering time will be lower and the number of turns of the steering wheel will be greater. This feature allows better control at high speed and at low speed of the machine.
When you turn the steering wheel at 90 RPM, the average steering time should not exceed the following time: ... 3.0 seconds
When you turn the steering wheel at 60 RPM, the average steering time should not exceed the following time: ... 4.6 seconds
If the steering times do not match the above values, see Testing and Adjusting, "Steering System Troubleshooting". The information is in this document.
Body Hoist Time
The hydraulic oil must be at normal operating temperature when the lift time for the hoist cylinders is checked.
Note: Make sure that there is adequate overhead clearance in order to fully raise the dump body.
- Start the engine and run the engine at high idle. Make sure that the dump body is lowered to the frame.
- Move the hoist control to the raise position. Start timing when the raise position is engaged. Reduce the engine speed as the dump body approaches the limit of travel. Damage may result if the hoist cylinders reach the stops at high speed.
- Move the hoist control to the lower position. Start timing when the lower position is engaged.
- Repeat the test several times in order to obtain an average time for each direction.
The average raise time should not exceed the following time: ... 12 seconds
The average lower time should not exceed the following time: ... 7.0 seconds
Cylinder Drift
Cylinder drift must be checked with the oil at normal operating temperature.
- Raise the dump body to an angle of approximately 45° and move the hoist control to the hold position.
- Measure the length of the exposed piston rod.
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Personal injury or death can result from a raised dump body falling. If a hydraulic line or component fails a raised dump body can fall. When working under a raised dump body, install the body prop (strut). |
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- Wait for five minutes and measure the length of the exposed piston rod. The difference is the drift.
The drift for a new cylinder should not be noticeable. The drift for a reconditioned cylinder should not be noticeable.
Used cylinders can be expected to drift up to 6 mm (0.25 inch) with the hydraulic oil at approximately 40°C (100°F). The drift will increase with higher oil temperatures.
Note: These figures are only for guidance. It is not possible to specify the amount of drift that can be tolerated before the cylinder needs to be reconditioned. The effect of the drift on the lift time will be insignificant unless the drift is visible to the naked eye.
Excess drift of the hoist cylinders may indicate any of the following conditions:
- The cylinder seals are worn or the cylinder surfaces are worn.
- The cylinder seals are damaged or the cylinder surfaces are damaged.
- There is leakage past the spool of the hoist control valve.
- There is external oil leakage.