LEVEL 1 MLT & MLA PRACTICE EXAM REVIEW NEWEST ACTUAL
EXAM WITH COMPLETE QUESTIONS AND CORRECT VERIFIED
ANSWERS (DETAILED ANSWERS) ALREADY GRADED A+ 100%
GUARANTEED TO PASS CONCEPTS!!!
The primary reason that machinery is replaced is due to:
a) Erosion
b) Accidents
c) Obsolescence
d) Surface degradation of the metal
e) Corrosion - <<ANSWER>>Answer: "d"
Sampling non-circulating, splash/bath machine sumps is best done by:
a) Drain Plug removal
b) Using a flexible, drop-tube, vacuum sample
c) Using a flexible, drop-tube, vacuum sample from the bottom of the sump
d) Obtaining a mid oil level sample from a fixed rigid tube within the sump
e) These systems should not be sampled - <<ANSWER>>Answer 81: d
The best method is to install a sampling valve equipped with a rigid stainless-steel tube.
The tube should be manipulated to be close to the zone of fluid movement (mid oil
level). A minimum clearance of 2 inches from any dynamic or static surface should be
maintained.
Drop-tube vacuum sampling of reservoirs and tanks is best done:
a) Off the bottom of the tank
b) Where the oil return line dumps back into the tank
c) Where the oil suction line pulls oil from the tank
d) From the top layer of the oil in the tank where water and dirt have settled out
e) From the middle of the tank - <<ANSWER>>Answer 82: b
This will help detect wear metals generated from system frictional zones before the oil
becomes diluted in the tank
For a typical hydraulic fluid, how full should a sample bottle be filled with hydraulic fluid?
,a) 50%
b) 75%
c) 90%
d) 100%
e) It doesn't matter - <<ANSWER>>Answer 83: b
A sample bottle should be filled to enable enough agitation by lab personnel to assess
the contaminants and wear metal contents. Otherwise, contaminants and wear metal
will stay in the bottom of the sample bottle and will not be measured, making the sample
unrepresentative. In addition, a sample bottle that is filled less than 75 percent may be
insufficient to perform all the required tests.
Oil sampling frequencies may be affected by:
a) Machinery age
b) Machine criticality
c) Fluid (oil) age
d) Operating conditions
c) All of the above - <<ANSWER>>Answer 84: e
• More frequent sampling is required when the equipment is new and old. This is
because of the high failure probability in these periods.
• The more critical the machine, the more frequent sampling is required.
• More frequent sampling is needed when the oil becomes old. This is because the
worse it gets, the faster it deteriorates.
• Operating conditions can include many factors such as high loads, extreme
temperatures, harsh environment, etc. Severe operating conditions require more
sampling.
A common sampling frequency for an industrial oil would be:
a) Every two weeks
b) Monthly (500 to 1,000 hours)
c) Quarterly
d) Six months
e) Yearly - <<ANSWER>>Answer 85:b
Wear is the primary cause of machinery replacement Surface degradation of the metal
includes all types of wear such as abrasion, adhesion, erosion, corrosion, etc.
Which of the following is not a lubrication regime (mode / type)?
a) Boundary
,b) Elastohydrodynamic
c) Boundarydynamic
d) Hydrodynamic
e) Mixed film - <<ANSWER>>Answer: "c"
• Boundary lubrication is defined as that regime of lubrication in which the load is carried
by the surface asperities rather than by the lubricant
• Elastohydrodynamic lubrication is a form of hydrodynamic lubrication (full film
separation). It is called elastohydrodynamic because the lubricated components deform
elastically due to high pressure as in antifriction bearings, gears and cams.
• Hydrodynamic lubrication is also called full film lubrication in which the load is carried
totally by the lubricant. The hydrodynamic film is a result of the relative movement of
surfaces and the viscous resistance of the lubricant
• Mixed film lubrication is a combination of full film and boundary lubrication. In this type,
the lubricant is insufficient to carry the load and provide full film separation. Some points
of contact still occur between surfaces.
Which maintenance strategy is based strictly on tasks performed at specific time
intervals?
a) Proactive
b) Predictive
c) Preventive
d) Percussive
e) Reactive - <<ANSWER>>Answer: "c"
Preventive maintenance is time-based. Generally, this type of maintenance is not cost-
effective because parts are changed prematurely and failures occur due to late or
improper maintenance.
Condition-based maintenance:
a) is based on the condition of the equipment and the early detection of faults
b) is based on regular time-based overhauls
c) Is based on run to failure
d) is based on the condition of the oil and other root causes
e) Answers a and d - <<ANSWER>>Answer: "e"
Condition-based maintenance is often referred to as predictive maintenance (PdM)
where the ultimate goal is to perform maintenance activity based on early detection of
problems using periodic or continuous monitoring, Obviously, (e) is the correct answer,
while (b) and (c) represent preventive and reactive maintenance, respectively,
The Pareto Principle (80/20 Rule) states:
a) The largest beneficial effect is obtained from a critical few maintenance tasks
b) The largest beneficial effect is obtained from the (random) many maintenance tasks
c) All machines die sometime
d) All bearings live forever
, e) 80 percent of the people do 20 percent of the work - <<ANSWER>>Answer: "a"
In general, the Pareto Principle states that, for many events, roughly 80 percent of the
effects come from 20 percent of the causes, so the correct answer is (a).
Which of the following is not a function of the lubricant?
a) Cool surfaces
b) Separate surfaces
c) Prevent corrosion
d) Repair surfaces
e) Provide some scaling - <<ANSWER>>Answer: "d"
The functions of a lubricant include controlling friction and wear by separating surfaces
in addition to cooling, corrosion prevention, sealing and transmitting power in some
applications such as hydraulic systems. The correct answer is (d), as surface repair
cannot be achieved using lubricants.
Which type or form of lubrication is considered to provide a full fluid (oil) film?
a) Elastohydrodynamic
b) Solid Film
c) Boundary
d) Mixed - <<ANSWER>>Answer: "a"
Elastohydrodynamic lubrication is a form of hydrodynamic lubrication (full film
separation). It is called elastohydrodynamic because the lubricated components deform
clastically due to high pressure.
Elastohydrodynamic lubrication (EHL) is considered to occur primarily in:
a) Piston rings and liners
b) Journal bearings
c) Rolling bearings, gears and cams
d) Slow-moving pins and bushings
c) Worm gears - <<ANSWER>>Answer: "c"
EHL occurs in systems where the contact area is small and the pressure is high, such
as rolling clement bearings. gears (at the pitch line) and cams. The mating surfaces
deform elastically to enlarge the contact area, which is why it is called
clastohydrodynamic lubrication.
The oil film thickness (or dynamic operating clearance) in operating bearings:
a) Cannot be determined
b) Is about 10 microns for journal bearings (although can vary considerably)
c) Is about a micron for rolling bearings
d) Is not measurable
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