214 & 224 WHEEL-TYPE EXCAVATORS Operating Errors Caterpillar

Operating Errors
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.


A. Running Gear


The transmission may only be shifted into high or low gear when excavator is stopped.

Shifting when the excavator is in motion will damage the hydraulic motor and the gearbox.

The costs resulting from this failure are considerable.

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

When driving downhill descents of more than 12%, always use the low speed gear. For that purpose put gear lever into neutral position, brake down to a stop, shift into low speed gear and then drive downhill.

During excavator operation, the combination switch of the gear lever has always to be either in the low speed position or in the high speed position.


B. Swinging


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.


Upon completion of the acceleration phase (remote control valve switched in neutral position), the automatic hydraulic pre-braking mechanism (throttled A - B connection in valve block) 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


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 protection.

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 lift cylinder 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 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 adverse effect on the hydraulic pumps.