213 TRACK-TYPE EXCAVATOR Operating Errors Caterpillar


Operating Errors
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1.1. A. Running Gear
2.1. B. Swinging
3.1. C. Excavator Operation

------ WARNING! ------

Operating errors occur rather frequently, and are not easily avoided. Special care should therefore be exercised in order to avoid operating errors that could cause direct or indirect damage. Read and understand the Operating Instructions.

--------WARNING!------

A. Running Gear

1. When working in the longitudinal direction with the backhoe bucket, the vehicle should travel backward or the attachment operate above the idler sprocket.

Due to the high ripping power of the backhoe bucket, the track links and the idler sprockets are subjected to high load (not the track bushings) if the drive sprocket were in front.

When the excavator is in deep ground and the tracks are heavily soiled, the drive sprocket always engages a clean track, because the track is always clean when it meets the drive wheel from above. If the excavator were to stop with the drive sprocket in front and then travel in reverse, the drive sprocket would engage the soiled chain and press the soil into the tooth gaps of the drive sprockets. This means that the tracks would ride high on the sprockets.

2. The above does not apply to operation with the loading bucket. In fact, the situation is, in part, reversed. When working with the backhoe bucket perpendicular to the tracks, make sure that the ripping does not tip the excavator excessively.

The tracks then sag downward and may come to rest next to the flange of the idler rollers. The load on the idler roller flange that is against the track on the ground is extremely high.

3. When traveling with loads, always use rear engaged drive sprocket so that the bushings are not subjected to excessive stress by the rocking of the vehicle.

4. Make sure the track tension is correct.

5. Avoid rotating the vehicle over depressions in the ground. The danger of the tracks coming off is considerable.

B. Swinging


NOTICE

Never operate the swing brake while checking with the swing motor. This places excessive load on the swing pinion and the toothed rim. It may also cause damage to the swing gear bearings.



NOTICE

Upon completion of the acceleration phase (pilot control valve switched in neutral position), the automatic hydraulic pre-braking mechanism (throttled A - B connection in valve bank) is activated. Check continued motion of the upper carriage with the swing brake. Braking with the swing motor gives rise to high oil temperatures and in no way improves braking performance.


C. Excavator Operation


NOTICE

1. Avoid moving the hydraulic cylinder into the end (bottoming out) position at full speed. Despite outstanding end damping, this will decrease the service life of the hydraulic cylinder.

2. Tamping or pounding with the attachments is especially hard on the machine. Not only does it place excessive load on the entire boom system, but it also gives rise to high peak pressures in the hydraulic cylinders that can not be completely eliminated by the line relief valves (inertia of the valves). If the cylinders are already in their end positions, the line relief valves will not be able to respond at all. In such cases there is no overload warning.

Example: With the stick cylinder extended all the way, stamping or pounding with the attachment will exert an uncontrolled tensile load on the stick cylinder.


3. Make sure that the throttle check valves for the boom cylinders and the stick cylinder are properly adjusted. If they are open too far, there is the danger of insufficient pressure and high lowering speed with high impact forces when the equipment is checked at that speed. If they are closed too far, high oil temperatures will result.

4. Frequent travel against the main relief valves will heat the machine unnecessarily. The entire hydraulic output is then converted into heat. If it is found that the power of the cylinder(s) is insufficient, reduce the gap.

5. The possibility of adjusting travel of the stick cylinder should be exploited. To ensure optimal service life and performance, extend only as far as absolutely necessary.

6. Switch off the engine during pauses in work. Under no circumstances should you let the engine idle at an excessively low speed, as the irregularities that then arise have an advese effect on the hydraulic pumps.