HET4 Failure/Fluid Analysis

Question 1

When doing fluid analysis, you can only analyze oils and coolant?

Answer 1

False, specialty fluids

and Exhaust gases or pneumatic system gases

Question 2

Describe Failure analysis

Answer 2

Systematic process to determine why their was a mechanical failure

Question 3

What type of maintenance program can fluid analysis help with?

Answer 3

Predictive maintenance program

Question 4

Schedule testing of fluid can show what trends?

Answer 4

Wear rates of internal components
Rate of deterioration and additive depletion
Amount/Time of external contamination

Question 5

What is spot-checking refereed to as?

Answer 5

Random fluid analysis

Question 6

Should ppm of wear particles be high or low during break-in period?

Answer 6

High

Question 7

What are the three major areas that a good oil analysis will show?

Answer 7

Deterioration of the oil itself (physical or additive)
Amount in PPM and type of wear particles
Presence of foreign contamination

Question 8

At what point in the stream should the 4 oz oil sample be taken?

Answer 8

Mid Stream

Question 9

If dirt/debris falls into the sample will you get an inaccurate sample reading?

Answer 9

Yes, make sure outside area is clean before taking sample

Question 10

Should oil samples be taken cold or when the oil is warm (recently operated)?

Answer 10

Warm - recently operated (contamination will be suspended)

Question 11

True or false:

Some metals can be both oil additives and also wear particles

Answer 11

True

Question 12

What are three ways to take an oil sample?

Answer 12

Live Machine
Hand Pump
Mid Stream

Question 13

What can cause a Viscosity increase in oil?

Answer 13

Contamination by a higher viscosity fluid
Running high operating temperatures
Extended drain intervals

Question 14

What can cause a decrease in oil viscosity in an engine?

Answer 14

Fuel dilution

Question 15

If an oil sample shows plenty of glycol, sodium and boron what is contaminating the oil?

Answer 15

Coolant/anti-freeze

Question 16

At what temperature does oil boil off water?

Answer 16

100°C

Question 17

Is a high Tin level on an oil analysis normal during break in?

Answer 17

Yes normal during break in

Question 18

How many steps can be involved in a failure analysis?

Answer 18

up to 9 steps

Question 19

What is the FIRST step involved in failure analysis?

Answer 19

Are there any concerns regarding liability?

includes: warranty, cost of repairs, personal/property damaged or other litigation

Question 20

What is the LAST step involved in failure analysis?

Answer 20

Complete reports and store vital information. (from reports to pictures)

Question 21

What should you do before “returning to service” and proving repairs are complete?

Answer 21

Test operation compared to manufacture/design specs

Question 22

When you are doing mechanical failure analysis, what should you keep during the process?

Answer 22

Anything that may be evidence:
filters
oil samples (fluid samples)
relevant materials (i.e bolts, gears, parts)
-Store to keep condition as is-

Question 23

What are three types of metal fractures?

Answer 23

Fatigue, Brittle, Ductile

Question 24

What are the three classifications of steel?

Answer 24

Low, Medium, High carbon

Question 25

When does a fatigue fracture usually happen?

Answer 25

Near the normal life expectancy - can be premature

Question 26

Brittle Fractures occur when?

Answer 26

Usually from shock or impact load

Question 27

Are fatigue fractures usually have smooth fracture surfaces?

Answer 27

Yes

Question 28

What does a sudden or brittle fracture produce on the surface?

Answer 28

Rough Fracture Surface

Question 29

Are ductile breaks(fracture) happen from one high stress?

Answer 29

It can result after being stressed multiple times

Question 30

What can determine the classifications of metal wear? (3)

Answer 30

Type of stress
Movement of the parts
Damage to the wear surface

Question 31

What are the types of metal wear? (7)

Answer 31

Visible wear
Adhesive wear
Abrasive wear
Surface fatigue wear
Brinelling (true/false)
Corrosive wear
Erosive wear

Question 32

What is the general cause of adhesive wear?

Answer 32

Lack of lube

Question 33

A part shows a build up of material and smearing, what is the wear called?

Answer 33

Adhesive wear (galling)

Question 34

What type of fracture is caused when there has been repetitive torque stalls?

Answer 34

Ductile Fracture

Question 35

If an engine is at a high RPM and the clutch is “dropped” engaged, what type of fracture can happen?

Answer 35

Brittle Fracture

Question 36

Abrasive wear is usually caused by what problem?

Answer 36

Contaimination

Question 37

Surface fatigue can be a result of?

Answer 37

Normal operation - old age

Question 38

When exhaust temp is 2500°F or higher what is produced?

Answer 38

NOx (oxides of nitrogen)

Question 39

Adhesive wear can also be shown as?

Answer 39

Galling (metal transfer)

Question 40

During a root cause analysis, it has been found to be contamination is the cause of the failure. Is this a good enough answer?

Answer 40

No, you must find wear the contamination can from or its cause

Question 41

If high CO is found in the exhaust, what could cause this?

Answer 41

Plugged air filter or bad air/fuel mixture