4-55.
Which of the following actions is a
part of the procedure for cleaning
a hydraulic system?
1.
Allow the system to remain idle
for 15 minutes after operating
it with a light load for 4
minutes
2.
Operate the system for 1 hour
while it is filled with
cleaning fluid
3. Operate the system at high
pressure while it is filled
with cleaning fluid
4.
Dilute the old hydraulic oil
with cleaning fluid and operate
the system for 15 minutes, then
allow the system to remain idle
for about 5 minutes
4-56.
You are replenishing the hydraulic
system with oil.
What strainer
should you use with the oil?
1.
A cheese cloth
2.
An aluminum filter
3.
A 200-mesh wire screen
4.
A 400-mesh wire screen
4-57.
If you are filling a hydraulic
system and notice water in the oil,
which of the following actions
should you take?
1.
Centrifuge the oil or reject it
2.
Run the oil through a 180-mesh
wire screen
3.
Heat the oil to permit the
water to evaporate
4.
Allow the oil to stand until
the water settles to the bottom
4-58.
What material is used to form the
shaft seal of most modern hydraulic
pumps?
1.
Rubber
2.
Neoprene
3.
Asbestos
4.
Flax
4-59.
Which of the following conditions
can cause the packing of a shaft
stuffing box to wear out quickly?
1.
Hard packing
2.
Rough shaft
3.
Shaft deflection
4.
Excessive packing
4-60.
What is the main purpose of packing
a shaft packing gland uniformly and
lightly?
1.
To allow for cooling and
lubrication
2.
To prevent scoring of the shaft
3.
To prevent leakage of seawater
4.
To prevent binding of the shaft
4-61.
A routine inspection revealed a
leak in the line of a hydraulic
system at a flanged joint.
If the
leak persists after you have
tightened the bolts evenly, what
corrective action should you take
next?
1.
Replace the flange
2.
Install new packing
3.
Inspect the fluids for
contaminants
4.
Install square-braided asbestos
packing
4-62.
The relief valve in a hydraulic
system leaks.
What should you do
to the valve seat?
1.
Reface it
2. Replace it
3. Regrind it
4.
Fit the valve with a seat
insert
4-63.
The selector switch on the conveyor
is improperly set.
Which of the
following troubles is most likely
to occur?
1.
Conveyor will not start
2.
Conveyor will not hoist
3.
Conveyor will run continuously
4.
Conveyor will not lower
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