Figure 9-52.—Backhoe bucket adjustment digging positions.
The
digging
trucks is
Figure 9-53.—Track-mounted excavator.
backhoe bucket can be adjusted for two
positions. The position for loading dump
shown in figure 9-52, view A. The position for
digging deep, vertical holes is shown in figure 9-52,
view B.
The backhoe can dig more material in less time
when a smooth, short dig cycle is used. When the bucket
is forced to excavate a load that is too large (when the
dipper stick control lever is pulled back and the bucket
is not moving), a “hydraulic stall” results in the loader
hydraulic system. When this occurs, the main relief
valve of the hydraulic system makes a noise, alerting the
operator to release the control lever.
NOTE: Hydraulic stalls cause the temperature of
the hydraulic fluid to increase that can cause premature
wear to the hydraulic system.
EXCAVATORS
Excavators are large backhoes used for heavier
construction tasting. The types used in the NCF
are either track mounted (fig. 9-53), truck carrier
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