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MLT
MLT I & MLA I Certification Review Exam
Questions with Correct Verified Answers,
Already Passed! (Complete & Accurate)
How does oxidized oil affect machine reliability? - ANS ✓Causes corrosive
wear, oil flow is hampered by varnish and sludge, filters plug, increase viscosity
causes heat build-up and oil flow problems.
Which test can be used to assess the depletion of antioxidant additives? -
ANS ✓Rotating pressure vessel oxidation test - others, FTIR, DSC, cyclic
voltammetry
What is the role of a rust inhibitor? - ANS ✓To produce a barrier film on oil-
wetted ferrous surfaces to repel water.
Name four lubricant types that are typically formulated with rust
inhibitors. - ANS ✓All lubricants, except some synthetics, are formulated with
rust inhibitors
Name a common lubricant that uses a detergent additive - ANS ✓Motor oils,
also some compressor oils, paper machine oils, and gas engine oils
What are the two functions of a crankcase oil detergent additive? - ANS
✓Neutralize acids and control deposits
Name the additive that is polar, envelopes soot, and keeps it finally divided.
- ANS ✓Dispersant
MLT I & MLA
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MLT
Name common causes of loss of dispersions in motor oil. - ANS ✓Coolant
contamination, Overextended oil drain, Water contamination High blowby, long
idling, high elevation, exhaust gas recirculation.
What are consequences of a loss of dispersancy? - ANS ✓Engine deposits,
sludge, impaired lubrication and oil flow.
What is the name of the additive that is primarily designed to control rust? -
ANS ✓Rust inhibitor
What is a common additive found in SAE 0W-30 motor oil but not found in
SAE 30 motor oil? - ANS ✓VI improver
In case of an oil that has operated for an extended period of time with
depleted antioxidant additives, how might the properties of that oil change?
- ANS ✓Viscosity increase, AN increase, darker color, putrid oil odor, the oil will
oxidize.
Name the additive that specifically reduces an oil's tendency to fail to flow
at cold start up temperatures. - ANS ✓Pour point dispersant
Name a common polymer used as an anti-foam agent. - ANS ✓Silicone
What properties are provided by the additive ZDDP? - ANS ✓Antiwear and
anti-oxidation
Which two metals are often seen on oil analysis reports that come from the
additive ZDDP? - ANS ✓Zinc and phosphorus
Name a common EP additive that is soluble in oil. - ANS ✓Sulfur phosphorus
MLT I & MLA
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MLT
Name four solid lubricants found in some gear oils and greases. - ANS
✓molybdenum disulfide, graphite, PTFE, borate.
Which of these two additives is commonly found in hydraulic fluids; AW or
EP? - ANS ✓AW
Name two additives commonly found in turbine oil. - ANS ✓Antioxidants and
rust inhibitors - also, demulsifying agents, foam inhibitors
Describe the three common ways additives can physically or chemically
decompose in service. - ANS ✓Oxidation, hydrolysis, thermal degradation.
Describe three common ways the mass of an additive can be lost from oil
during service. - ANS ✓Absorption, water washing, Filtration , gravity
separation, evaporation, particle stripping.
Larger (heavier) oil molecules are associated with high or low viscosity? -
ANS ✓High
Kinematic viscosity is measured using a capillary gravity flow viscometer or
rotating spindle viscometer? - ANS ✓A capillary viscometer
How can heat permanently reduced oil's viscosity? - ANS ✓Cracking
What property of oil measures an oil's internal resistance to flow and
shear? - ANS ✓Absolute viscosity
When oil is momentarily heated, how will its viscosity change? - ANS ✓It will
go down
MLT I & MLA
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MLT
How can heat permanently increase oil's viscosity? - ANS ✓Evaporative
losses, oxidation.
Name three contaminants that can reduce oil viscosity? - ANS ✓Fuel, solvent,
refrigerant.
What effect does emulsified water have on oil viscosity? - ANS ✓Increases it
How does soot in diesel engine oil affect oil viscosity? - ANS ✓Increases it
How does glycol contamination affect oil viscosity? - ANS ✓Increases it
What is the ISO viscosity grade that sequentially follows ISO VG 320? - ANS
✓ISO VG 460
What percentage increase in viscosity does each ISO viscosity grade have
over the one just below it? - ANS ✓50%
The viscosity designated by 80W-140 is associated with crankcase oils or
driveline gear oils? - ANS ✓Gear oils
An oil with a viscosity index of 135 is likely a VI improved mineral oil or a
straight grade oil? - ANS ✓VI improved
A base number will typically increase or decrease as the oil ages? - ANS
✓Decrease
Flash point increases or decreases as oil viscosity increases? - ANS
✓Increases
MLT I & MLA
