Final Exam Question Bank Flashcards
Lint from cleaning rags can be harmful to hydraulic systems because the lint ___.
…can clog filters and promote component leakage
If a radial piston hydraulic pump fails to deliver rated fluid volume, the cause can be ___.
…obstructed suction passage
When the tilting box of a variable stroke axial-piston pump is perpendicular to the pump shaft, which of the following conditions will exist?
…there is no fluid flow
The hydraulic system of a deck winch has been drained, flushed, and refilled with hydraulic fluid. An erratic knocking noise from the hydraulic motor when the winch is started would indicate ___.
…air trapped in the system
The usual number of single-acting pistons used in a variable stroke axial-piston pump is ___.
…7 to 9
An axial piston pump differs from a radial piston pump as the pistons of an axial piston pump are positioned ___.
…parallel to each other and to the shaft
Which of the following problems may be encountered by using an oil having a viscosity higher than that specified for an operating hydraulic system?
…increased power consumption
A casing drain is provided for axial piston and bent axis variable stroke pumps to ___.
…prevent damage due to agitation and overheating of oil accumulated in the casing as a result of normal internal leakage
What is the prime mover?
…energy source that drives the pump
When installing a hydraulic hose, which of the following precautions should be taken?
…the hose should not be twisted
…the hose should be protected with a sleeve if it is subjected to rubbing
…there should be some slack in the hose
(all of the above)
What is the pressure at the bottom of a 20ft column of oil?
8 psi
0.4 psi per foot
Fatigue wear is defined as ___.
…particles bridging a clearance causing a surface stress riser or micro-crack that expands into a spall due to repeated stressing of the damaged area
After installing a hydraulic hose, which of the following precautions should be taken?
…the filters and strainers should be checked frequently
The speed of a radial piston hydraulic motor is controlled by…
…varying the fluid flow rate discharged to the motor
New piping and tubing to be installed in a hydraulic system can be safely degreased by using ___.
…a special petroleum solvent
The ability of an oil to separate cleanly from an oil and water mixture is referred to as its ___.
…demulsibility
Which of the following statements is/are true regarding hydraulic pumps in general?
…variable volumes can be obtained with gear pumps only by variation of the pump drive speed
Tubing is sized by…
…nominal outside diameter
Which of the listed pressure control valves would be used to establish the maximum operating pressure of a hydraulic system? Pressure-reducing valve Unloading valve Counterbalance valve Pressure-relief valve
Pressure relief valve
The pressure of an operating hydraulic system, as indicated by a pressure gauge is a result of the fluid flow overcoming:
- internal resistance to flow
- resistance of the internal components
- the load applied to the system
all of the above
What pressure is usually available to push liquid into the pump inlet?
atmospheric pressure
Hydraulic pumps most commonly used in steering systems are of the…
…axial piston type
With which component does the design of a hydraulic circuit begin?
…the actuator
When changing to a fire resistant hydraulic fluid in a system, it is important to check the compatibility of the new fluid with the systems:
seals
metals and plating
paint
all of the above
