Cooling and Lubrication System Maintenance Part 8 docx

Given a situation describing possible faults or | conditions within an engine's lubrication system, state the one piece of test equipment used to determine the fault... State in writing

3403 Sampling Requirements and Techniques

a Sampling Requirements Marine Corps Technical Instruction TI-4731-14 provides a list of all equipment and components of equipment that are to participate in the Joint Oil Analysis

Program Currently all engines and transmissions for 5 ton

tactical vehicles and the LVS front power unit are included in the progran

Sampling is conducted every 90 days or when a special sample is required; table 3-2 tells you when special samples are required All samples that are submitted as special samples must be marked

"special" with the reason for the submission indicated

Table 3-2 Circumstances Requiring a Special Oil Sample

Obtain a special sample WHEN

e the laboratory requests a special sample

e there is indication of internal damage to the

engine or transmission due to an oil related failure

® your maintenance supervisor tells you to change

the oil

@® you have performed oil services due to changes in

environmental conditions

® you have done an oil change BEFORE

ws scheduled services

m performing maintenance on the engine or transmission (This includes the repair, replace- ment or installation of any oil lubricating part or assembly.)

= removing the engine or trans- mission, (regardless of the reason)

m= anticipated abnormally severe operating conditions

® you have done oil changes AFTER

= maintenance on the engine or transmission

w overhaul or replacement of the engine or transmission

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As you can see, this covers just about all occasions The bottom line is to use the program and know what components need

sampling

Now, what publication lists all the equipment that participate in

the JOAP?

If you said TI-4731-14/1, you're correct This publication also provides detailed instruction on sampling methods and the overall Joint Oil Analysis Program

b Sampling Techniques

There are two methods used to obtain oil samples the oil

sampling pump (fig 3-31) and the sampling valve method

of,

AC |

Ñ#=<

Opec”

Fig 3-31 Oil sampling pump

Fig 3-32 Oil sampling valve

The sampling valve method is best It takes less time, is much easier to use, and provides a cleaner sample of a component's

oil

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Lesson Summary In this lesson you listed the benefits of the oil analysis program, identified the publication used to

determine the equipment to be sampled, and identified the two methods used to obtain the samples In the next lesson you will find out how to inspect and test lubrication systems

Exercise: Complete items 1 through 3 by performing the action

Lesson 5

required Check your responses against those listed

at the end of this study unit

What are the three benefits achieved from using the Joint Oil Analysis Program as a part of your preventive

maintenance program?

a

C

What publication provides a list of equipment and

components that require oil sampling?

List the two methods used to obtain oil samples

INSPECTING AND TESTING THE LUBRICATION SYSTEM LEARNING OBJECTIVES

1

2

Given statements describing leaks, identify in writing the classification for each leak

Given a situation where an operator reports a leak to you, the mechanic, state in writing the action required List the parts or areas where oil leaks are most likely

to occur

Given a situation describing possible faults or |

conditions within an engine's lubrication system, state the one piece of test equipment used to determine the fault

5 State in writing the publication that provides procedures for testing for low oil pressure at the organizational level

6 State in writing the fault that could very easily cause enough excessive pressure to build up within a

transmission to cause seals and gaskets to start leaking

7 Select the procedure for testing the operation of the transfer case oil pump on the LVS |

8 State in writing procedures for testing the number 1 and number 3 axle assemblies on the LVS

In lesson 4, oil analysis was described as a preventive

maintenance practice used to test the oil for contamination and wear metal particles Even with oil analysis, other maintenance inspections and tests are still required If you use the JOAP in conjunction with the preventive maintenance inspections and

testing procedures covered in this lesson, you can prevent many serious problems

3501 Lubrication System Inspection

Other than contamination, the lubrication system's number one enemy is a leak Even though the oil analysis helps identify contamination problems, when it comes to a leak, you're on your

a Oil leaks (general) It was once said, "Wet on the outside means dry on the inside." This isn't always true, but it's a good bet that, when it comes to oil lubricated components, it could be Keep this statement in mind when you're inspecting components You should also consider the oil capacity of

components when deciding how severe a leak is

For example, a leak of one

Grop per minute would not be a

major problem on the hydraulic

reservoir of the LVS The

reservoir (fig 3-33) has a

capacity of 96 qts! So it's

very unlikely that enough oil

would ever leak out at that

rate to cause serious damage

On the other hand, if the air

shift unit (fig 3-34), which

holds only a very small amount

of oil, had a leak of one drop

a minute, it would be

completely dry in a very short

time

So, if a small leak is not

repaired immediately ona

component like this, serious

damage to the equipment will

result

HYDRAULIC RESERVOIR a SIGHT GLASS >

Fig 3-33 LVS hydraulic reservoir

Fig 3-34 LVS air shift unit

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There are three classifications of leaks:

e Class I Leakage of fluid indicated by wetness or

discoloration but not great enough to form drops

e Class II Leakage of enough fluid to form drops, but not enough to cause drops that fall from the part being

checked or inspected

e Class III Leakage of enough fluid to form drops that fall from the part being checked or inspected

As a general rule, operation of the equipment is allowable with Class I or II lubricant leakage For safety reasons, brake fluid

is an exception to this rule; you must repair or replace any

component(s) that are leaking brake fluid

Class III leaks, when found by an operator, will be reported to you, the organizational mechanic It is your job to determine how severe the leaks are (verify the classification), and

determine if the equipment can be safely operated Class III leaks are cause for deadlining

b Component leakage Leakage can occur almost anywhere

However, some areas or parts are more prone to leaks than others Gaskets, hose connections, plugs and fittings, and seals are

where leaks are most likely to occur You may have to search to find the true source of leaks For example, a leaking engine oil pan gasket may cause the transmission or other components to

appear to be leaking but the leak could be due to oil being blown over other components when the vehicle is moving You should clean components thoroughly and then operate the equipment while looking for signs of fresh oil

(1) Gaskets Gasket leaks normally occur because the

material has dried out or cracked Leaks will also occur around gaskets because of surface damage to components or loose mounting bolts This is especially true for

components like oil pans and valve covers Once a leak starts, it's hard to regain a good seal without replacing

Oil filters are frequently over-tightened, destroying the filter gasket Applying a little oil to the filter

gasket will help provide a seal Then be sure to torque filters in accordance with specifications

(2) Hose connections Loose or over-tightened hose clamps commonly cause leaks

(3) Fittings and plugs Pressure fittings and "0" ring seals

on high pressure lines (hoses) are also common sources of leaks The best fix for a leaking fitting or seal is to replace it

(4)

Drain plugs on the housings of most components have

copper gaskets designed to be used only once These

gaskets are often overlooked when changing oil and may leak Fittings often become loose and are a prime source

of leaks Teflon tape or pipe sealer will help provide a seal and prevent them from working loose

Seals Most seals will show signs of moisture around sealing surfaces but this does not mean the seal is

leaking Seals require lubrication to prevent premature wear of the sealing material Seals without this

moisture will dry out and develop leaks Dirt and rust are a seal's worst enemies; they act as an abrasive which can destroy seals You must replace damaged seals

The following vehicle components often leak

Oil fill plugs Oil filter Valve cover gaskets Output shaft seals Sending units

Wheel seals Flange gaskets Front seals (engine)

Oil pan gaskets Oil drain plugs Oil coolers Input shaft seals Rear main seals Hydraulic hoses and fittings Differential cover

Before we go on, let's see how much you're learning What action must a mechanic take when an operator reports a class III leak?

Now, in the spaces provided below, write the definitions for all three classes of leaks

The four most common parts or areas that leak are:

Now that we have completed the serious business, let's have some real fun working a word search puzzle Your task is to locate the names of the parts/components that often leak As a hint, there is no spacing between words: for example, valve cover

gasket will appear as valvecovergasket |

MIS

WCIMDSSGULPNIARDLIO YDRAULICHOSENJGQODL IYEYHWDAFRONTSEALVB MOAROVICLQYGUFKLRMK QJRFOUFOILPANGASKET OYMLGRFRTINUGNIDNES UVAACBEMRKMBWTWSMGB TAINNVRXEXLARLXPQDF PXNGTWEBVUOILFILTER ULSEVINPUTSEALBKUPX TAEGRQTVEKKAGQNJPTV SEAABKIEFGSWHNQCFFJ ESLSPUALJTTNMKHAYMNQ0 ALEKRHLBOILFILLPLUG LENETRCOKJHUHNSVAYW SENTJRORVDKAUUCBOSO OHYQRCVNXOILCOOLERF BWHNCSEEQSCNHRQUUJH

The answer to the first question is:

You should verify the classification of the leak

The definitions for the three classes of leaks are:

Class I

Class II

Class III

Leakage indicated by wetness or discoloration but not great enough to cause drops

Leakage of enough fluid to form drops, but not enough to cause drops that fall from the part being checked or inspected

Leakage of enough fluid to form drops that fall from the part being checked or inspected

The four most common parts or areas that leak are:

e fittings and plugs e seals

The solution to the puzzle is:

-VALVECOVERGASKET- - GULPNIARDLIO

HYDRAULICHOSE -

-~ E -D-FRONTSEAL

“ee Ree & Treew8weweee ke & =- ~ -RF FOILPANGASKET -O-ML F-TINUGNIDNES ~-U-AA E * -" -

-T-IN R -

-P-NG E -OILFILTER -ULSE-INPUTSEAL -

~-TAEG T + -

-SEAA I -+ -

-ESLS A -

-AL-K L-OILFILLPLUG -LE-E C -

E-T 0 -

H V OILCOOLER- ~-W E-+ -

~~ eo we = = = wow a

If you had a difficult time answering any of these questions

review paragraph 3501 before continuing with the lesson If the puzzle gave you a tough time, take another look You're not

losing your mind! Some of the answers are written right to left

or bottom to top, but all fifteen components listed in the box on page 3-51 are included

3502 Inspecting and Testing the Engine Lubrication System

The two conditions that should cause you to inspect and/or test the engine lubrication system are low oil pressure or high oil consumption To locate the problem, you should first perform the inspection If you still can't locate the problem, you will need

to test the engine The one piece of test equipment that you have in the motor pool to test for low oil pressure or high oil consumption is the STE/ICE Use it to locate the fault You'll find the test procedures for organizational maintenance in the technical manual (TM-20 series) for the equipment being tested Let's now look at some of the possible reasons for low oil

- pressure or high oil consumption

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a Low oil pressure There are several reasons for low oil

pressure It could be caused by something as simple as a low oil level or something as complex as worn main bearings Table 3-3 starts with the most common causes of low oil pressure and the easiest inspection procedures and works up to the most complex causes and procedures for diagnosing then

Table 3-3 Procedures for Diagnosing Low Oil Pressure

Problem To confirm the problem, inspect

or check

Low oil level

Diluted oil

Oil pan structural

damage

Inoperative oil

pressure gauge

Inoperative oil

pressure sending

unit

Lubrication system

failure

components for external leaks coolant for the presence of oil

engine for excess blowby

oil for possible fuel contamination

oil pan for dents that may interfere with oil pump operation

oil pressure gauge reading

=» Conduct STE/ICE GO-NO-GO test 05

Conduct STE/ICE GO-NO-GO

sending unit test 31

the following components for blockage or obvious damage:

w oil filter oil cooler pressure regulator valve oil lines

0il pump pick-up tube and screen

Oil pump (not inspected or tested at

organizational level.) Engine damage e the engine for obvious damage

(no repair at organizational level)

b High oil consumption High oil consumption is caused by

either external or internal leakage External leaks, as

previously discussed, occur around gaskets, seals, hoses, hose connections, filters, and drain plugs |

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