GENERAL MAINTENANCE INSTRUCTION NO: 18
GENERAL MAINTENANCE INSTRUCTIONS FOR
VEHICLES AND EQUIPMENTS
1. INTRODUCTION
Vehicles and equipments are
indispensable tools for construction of roads in border areas, at high
altitudes and rugged terrains. Some equipments are so deployed that failure of
the single equipment may prove very costly and slow down road construction and
delay restoration of communication. In some regions, the roads are such that to
replace defective equipment such as tractor, road roller by a serviceable one
is laborious and time consuming and even at times may be impossible. It is
therefore, of utmost importance that the equipment is operated and maintained
at a high standard of fitness to derive maximum benefit and life out of the
equipment.
2. RESPONSIBILITY
FOR MAINTENANCE
(a)
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NECESSARY FOR A HIGH STANDARD OF
MAINTENANCE:-
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It is only by the adherence to the
principles of maintenance as embodied in a comprehensive program and carried
out by operators to the smallest detail that the utmost efficiency in the
operation of vehicles and equipment can attained, costly repairs and
replacements can be avoided and the maximum number of vehicles and equipment
can be kept on the road in first class running order. Efficient maintenance
necessitates concentration on the simpler tasks by the users and handing over
the more advanced repairs and adjustment to the skilled workshop and
technical personnel/ facilities.
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(b)
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REQUIREMENTS
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Mechanical
efficiency of vehicles and equipment can be said to be achieved only when a
maximum percentage of the total vehicles and equipment on charge of a unit
are kept fit for longest duration and ready for immediate use. A unit in
Border roads which has kept its equipments in good working order 80% of its
total equipment day (ie 25 days out of 30 days in a month) in a year will be
considered efficient. The Chief Engineers may initiate suitable monthly/
quarterly return to watch this aspect of equipment performance. To ensure
this, a unit commander has to maintain strict supervision on equipment
maintenance.
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RESPONSIBILITIES OF DIR (EME)/SO 1 AT
PROJECT HEADQUARTERS WITH REGARD TO MAINTENANCE
(a)
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DIR
EME/SO I at Project Headquarters is the Technical Adviser to the Chief
Engineer on all matters affecting the repair/ maintenance and inspection of
all vehicles/ equipment in the Project.
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(b)
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He is directly
responsible to the Chief Engineer for the general efficiency, repair and
recovery of technical equipment of the Project.
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(c)
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His Chief duty is to ensure that the maximum
possible proportion of the equipment is in a serviceable condition.
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(d)
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He will ensure that the inspection of
equipment for which he is technically responsible is systematically carried
out.
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(e)
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He will ensure that :-
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i)
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Action is taken promptly in all
authorized modifications.
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ii)
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Units are given every possible
assistance in the care of their equipment and that they are advised as to
action required to obtain necessary technical information.
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iii)
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That the procedure laid down for
reporting defects in the equipment is properly carried out by all concerned.
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iv)
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All instances of neglect or misuse of
equipment that come to his notice are brought to the attention of the Chief
Engineers /Headquarters Directorate General Border Roads.
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v)
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He keeps himself and the Chief
Engineer thoroughly acquainted of the condition and percentage availability,
which is his concern.
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vi)
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He visits units/inspects equipments
as necessary for the above purpose.
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vii)
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Ensure quality and promptness in
field repairs.
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PRINCIPLES OF MAINTENANCE
(a)
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Cleanliness of the equipment particularly the
working area is very essential.
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(b)
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Inspections- Regular and routine inspections must be rigidly carried
out.
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(c)
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Lubrications Periodicity and correct grade of
lubricant must always be adhered to.
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(d)
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Preventive repairs- When a part such as fan belt, brake
shoe, clutch plate, oil filters, fuel filters, tyres, bearing, oil seal,
hose, joints, gaskets, spark plugs are in an advanced stage of deterioration,
it should be replaced.
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(e)
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Timely repairs- Faults which cannot be rectified must be reported
immediately. Work beyond the capability of the operator or unit tradesmen
must not be attempted as, apart from the possibility of damage this leads to
neglect of the simpler tasks which are essential to avoid more extensive
costly repairs and replacement.
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(f)
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Special maintenance instructions- Require to meet the operating
conditions and specialty of equipments must be strictly followed.
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IMPORTANT ASPECTS OF MAINTENANCE
Inspections
5. To assess the mechanical condition and to
provide timely repairs of all vehicles, equipment and plants held by various
units, periodical inspection as below will be carried out ;-
(a)
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‘B’
Vehicles.
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By Field Workshops –Once a year.
By Dir EME/SO 1 –Once a year.
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(b)
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Engineering
and Other miscellaneous Equipments.
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By
Field Workshops –Twice a Year.
By
Dir EME/SO 1 –Once a year.
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6. The program for the inspection by Field
Workshop / Dir EME/SO 1 will be so
coordinated so as to ensure that the inspection is carried out at regular
intervals.
Timely Repairs
7. The old saying “STITCH IN TIME SAVES NINE”
must be rigidly followed as for as the repairs to the equipments are concerned.
Minor defects should not be neglected as these will become major defects if not
attended to in time. Defects must be attended to as soon as noticed. The
Unit/Task Force Commander/Chief Engineers should examine this aspect during
their visits/inspection to the units.
Running in Period
8. The life of any vehicle/equipment will invariably
depend on how the equipment has been run during the running in period. Needless
to say that, the speeds and the loads should never be exceeded during this
period. Most of the projects have their units period should be completed in
plains before taking new/ overhauled equipment to the unit location in hills.
Supervision for Maintenance
9. Lack of effective supervision in carrying
out the various maintenance tasks will have an adverse effect on the
maintenance and consequently on the availability of the equipment. Dir EME/SO 1 at Project Headquarters must
device their own ways and means to ensure that the various maintenance tasks
are carried out regularly under proper supervision of trained personnel. Each
Project will evolve an organisation system and drill for it.
Mobile Maintenance Teams
10. When a Task Force has many detachments out
and dispersed, many maintenance facilities cannot be provided and supervision
tends to be poor. Also, after using and equipment for the full day,
particularly when working hours extend too late in the evenings to achieve the
targets, in view of the limited holding of the equipment, the operators may not
be able to undertake all aspects of maintenance.
11. Task Force may, therefore, organize Mobile
Maintenance Teams from within their resources (Jeeps/ trucks and technical and
non technical personnel) who should be made responsible for certain maintenance
aspects only such as preventive repairs. Special lubricants, adjustments and
running maintenance will still be the responsibility of the drivers /operators.
These teams should work to a schedule under direct control of Officer
Commanding Field Workshop and should be able to carry out through maintenance (especially
hourly /mileage tasks) of vehicles/ equipments and plants held by the Task
Force at regular intervals. The Officer Commanding Field Workshop would need a
jeep and unit tradesmen/ personnel to be allocated by the Task Force Commander.
The working of the Mobile Maintenance Team will be reviewed after six months.
Utilisation of Equipments
12. Task Force Commander in their enthusiasm to
achieve their target, at times have been utilizing their equipments
continuously and also in double shifts
without giving any time to the operator to carry out its regular maintenance.
This naturally has an adverse effect on the performance of the equipment and in
the long run, effect on its working and life. Short-term gain results in
long-term loss. As far as possible, it should be ensured that such situation is
avoided. Operators must be given time for their maintenance.
Premature Failures/ Downgradation
13. The life of each equipment has been laid
down by Headquarters Directorate General Border Roads vide letter No.
16155/EME/TM/BRD dated 08/10 Dec 64. Majority of the equipment should be able
to achieve this target if regular the users carry out maintenance. If however,
due to any reason the equipment fails to achieve even 75% of the specified
life, the matter should be properly investigated through a Board of Officers
vide Headquarters Directorate General Border Roads letter Number
16187/DGBR/E4/T dated 08 Oct 69. Remedial actions will be taken as per the
recommendation of the Board.
Training of Operators
14. Training of personal both in operation as
well as maintenance is extremely essential and should be organized in a
realistic manner in each Task Force. When over a new operator is given charge
of a vehicle/plant or machinery, he must be first trained by the supervisory
staff of the unit of the operation and maintenance to be carried out. For this,
refresher course for the supervisory staff may be conducted under officer
commanding Field workshops. This will go a long way in helping the Task Force
Commanders to achieve their targets. As with better-trained operators and more
effective maintenance, there will be less changes of the breakdown of the
equipment.
15. Prior to receipt of a new type of equipment
a training cadre should be conducted. In case Chief Engineers need assistance
of the manufactures, Headquarters Directorate General Border Roads will be
approached. Base Workshops and Field Workshop will get their trade man also
trained on new equipment through local courses and manufactures.
Procedure
16. In order to avoid haphazard work and to
ensure that no points are over locked, operators will carry out maintenance in
a systematic manner. Experience shows that the tasks, which have to be carried
out on equipment, can be divided as follows: -
(a)
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Running
Maintenance.
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(b)
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Tasks,
which are to be, carried out on time –basis and periodicity basis.
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(c)
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Tasks,
which have to be carried out on mileage/hrs basis.
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Running Maintenance
17. First Parade (To be done Before the
vehicles/equipment in employee)
(a)
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Check fuel, oil and
water.
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(b)
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Clean windscreen, windows and
driving mirror.
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(c)
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Check tyre pressures and inflate if
necessary.
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(d)
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Start engine and check lights, wind
–screen wiper, traffic indicators and horn.
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(e)
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Check whether ammeter is registering
and oil pressure gauge is indicating.
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(f)
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Check operation of brake pedal.
Drain water from vacuum brake system if fitted.
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(g)
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Examine for oil, fuel and water
leaks.
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(f)
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Listen for unusual knocks, rattles
and uneven running of engine.
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18. Halt Parade (To be done during halts
between long runs)
(a)
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Check
oil, water and fuel and replenish if necessary.
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(b)
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Check
for oil leaks from all assemblies and under chassis.
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(c)
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Visually
check tyres for correct pressure. Check for presence of pieces of
flint/stone/glass lodged in the tread, and remove same if present.
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19. Last Parade (To be done at the end of
day’s work)
(a)
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Carry out checks shown in Halt
Parade.
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(b)
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Examine Road springs for loose ‘U’
bolts and broken leaves.
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(c)
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If ordered, carry out frost
precautions.
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(d)
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Enter mileage/hours, fuel and oil
drawn in the log book.
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(e)
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Leave the equipment ready to move
off.
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(f)
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Record in the logbook, weekly,
Monthly and mileage/hourly tasks carried out.
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(g)
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Reports if engine
overheat, oil pressure too high/ low, charging rate too high/ low and MPG
low.
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Tasks to be carried on a Time - Basis
20. A few hours should be allowed in a week for
each vehicle/equipment for carrying out the various weekly and monthly
maintenance tasks as specified in the General Maintenance Instruction No.06
& 07.
21. The first three letters of the maintenance
day should be painted prominently in the front portion of the vehicle/equipment
to indicate the day of maintenance. The vehicles /equipment should be put in to
use on this day only after the maintenance tasks are complete. These tasks must
be performed under the supervision of at least an NCO/Grade I and a proper
record for the same maintained in the logbook, which must be checked monthly by
unit Mechanical Transport Officer and Field Workshop.
Task to be carried out on
mileage/Hours –Basis
22. Task bases on mileage/hours run should be
carried out as specified in the General Maintenance Instruction No. 06 and 07.
23. In addition to the above is some tasks are
specified by the makers in the operator’s/Maintenance Manual issued along with
each equipments, these should also be completed and a record to the effect made
in the logbook. Field Workshop through Equipment Officers’ Conference may bring
these tasks to the notice of units.
24. Where there are more than one makes of and
equipment such as road rollers. Compressors, Stone crushers, vehicles Dir EME/SO 1 may combine the specified
maintenance tasks into a common maintenance tasks for all the makes/models of a
same category of equipment. When necessary, advice of specialist will be asked
for.
Lubrication
25 General
The most vital aspect of maintenance in
any equipment is lubrication. Lubrication may be divided generally into three
classes.
(a)
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Lubrication
of the engine.
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(b)
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Lubrication
of the gearbox, transfer case, axles and steering box, reduction gear, drives.
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(c)
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Lubrication
of the chassis working parts including wheels.
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26. Lubrication
charts are provided for all makes and type of vehicles and equipment in the
service. These charts show the type of the lubricant to be used for the various
parts of the vehicles/equipment and in certain cases the frequency with which
it should be applied (Refer General Maintenance Instruction No.5)
27. A reserve of engine oil should always be
carried in the tin provided for this purpose. Care should be taken that the top
of the tin is wiped clean and dry before the screwed cap is removed and oil
poured out.
28. Lubrication
of the Engine.
(a)
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It
is essential that the correct grade of oil as laid down for the particulars engine is used. Only in an
extreme emergency will another grade of engine oil be used in which case the
nearest specification to that laid down for the engine will be used. On no
account will two grades of oil be mixed. If an alternative grade has to be
used the original oil will be completely drained.
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(b)
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A
“Dip Stick” indicator is incorporated on all vehicles except motorcycles.
This dipstick is graduated and shows the depth of oil in the engine sump.
This dipstick will be inspected frequently and the oil kept up to the full
mark. The procedure for checking the oil level in the sump is as follows: -
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(i)
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Place
the equipment on level ground.
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(ii)
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Stop engine.
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(iii)
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Await a few moments to let the oil
settle in the sump.
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(iv)
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Remove dipstick and wipe it clean
with a clean cloth. Cotton waste must not be used.
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(v)
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Replace dip stick –remove-check
level.
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(vi)
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Pour into engine sump estimated
amount of oil required and re-check.
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(c)
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When filling or “topping up” the
sump the oil funnel with the coarse gauge filter with be used. The cap and
oil filter neck will be wiped clean prior to removing the cap for filling to
ensure that no grit or dirt enters in to the sump.
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(d)
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The majority of engine lubricating
systems are fitted with an oil pressure indicator or gauge. The correct
registration of the gauge shows that the oil in the engine is being
circulated correctly. The gauges or indicators vary in type, the majority
however, are of the dial type fitted to the dash board of the vehicle. If in
doubt as to the correct oil pressure refers to maintaining workshop.
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(e)
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The operator’s first duty after
starting the engine is to ascertain from the pressure gauge that the oiling
system is working correctly. He should also during the course of his duty
glance occasionally at the oil gauge for the same purpose.
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(f)
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If oil pressure gauge is not
provided/working. Removing the filter cap from the oil tank and observing the
nature of the oil in the tank can ascertain the circulation of oil. Froth on
the oil indicates that oil is circulating properly.
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(g)
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It is important that the external
area of the oil sump I kept free from mud and oil. This facilitates the
dissipation of heat from hot oil in the engine sump.
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Lubrication of gear boxes and driving
axles
29 Oil filler plugs are provided for gear
boxes and rear axles on nearly all equipments. These filler plugs also serve to
indicate when an axle or gear box contains the correct amount of lubricant.
When filling or topping an axle or gear box these plugs should be removed and
the lubricating oil poured in until it begins to run out of the filter plug
hole. It is important when filling the rear axle to ensure that the equipment
is on the level. Overfilling is likely to occur if the front of the equipment
is lower than the rear. Overfilling of driving axles will result in oil getting
into the brake drums.
30. Chassis
Lubrication
(a)
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A regular routine of chassis
lubrication must be incorporated in all maintenance programs. A diagram
indicating the various lubricating points should be available in the Mechanical
Transport section /Logbook of the equipment. Colour code should be given for
each type of lubricant to be used in the above diagram.
All lubricating point should be painted
with the code colour to facilitate the operator to identify the correct lubricant
to be used. Kilometer/hours run may also be indicated near the lubricating
point for ready reference Operators should be trained on this diagram and as
far as possible the lubrication tasks must be done supervision.
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(b)
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Chassis lubrication is
divided, generally speaking, into two parts :-
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(i)
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Lubrication by oil
or grease gun- The
lubrication chart shows all the points to be lubricated and the type of
lubricant to be used for each point. Nipples or lubricants will be wiped
clean before the gun is applied and the lubricant will be injected until is
commences to come out from ends of the bearing or joint being lubricated. If
the lubricating fails to pass, it indicates a effective lubricator or a
blocked oil way which should be attended to early.
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(ii)
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Oil cane
lubrication - The
oil can is intended for lubricating small bearings for which no oil gun
arrangements are provided. These are usually enclosed bearings of electric
assemblies, such as dynamos, self starters, magnetos and exposed joints which
should be wiped clean and few drops of oil inserted between the jaws of the
joint. The procedure for the lubrication of electrical accessories is given
in the next paragraph.
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Colour –coding in lubrication
31. Every nipple, and oil filter cap should be
colour coded. Such colour codes should indicate: -
(a)
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Periodicity.
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(b)
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Responsibility.
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(c)
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Lubricant.
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(d)
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Location.
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An operator without looking at any
document, should be able to lubricants his equipment. On a prominent place in
as equipment, the number of lubrication points to be lubricated with different
lubricants will be stenciled.
Lubrication of electrical accessories.
32. Dynamos, self-starters and magnetos should
be lubricated very sparingly. Two or three drops of oil the same specification
as used in the engine every two month or 1000 miles/hours are sufficient. Over
lubrication of an electrical assembly will cause the oil to penetrate on to the
commentator and into the armature, causing damage to the insulation of the
winding.
Maintenance of Engines
33. Maintenance by the driver comprises the
following tasks:-
(a)
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Cleaning the engine.
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(b)
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Maintenance of gas, water and oil tight joints.
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(c)
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Periodical changing of engine oil.
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(d)
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Attention to oil filters, sparking plugs and fan belts.
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(e)
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Lubrication of external working parts.
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(f)
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Ensuring that all nuts and bolts other than cylinder
head nuts and nuts fitted with split pins are kept tight.
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34. Maintenance
of gas tight joints
(a)
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Gas
tight joint comprise the cylinder head joint, sparking plug joints,
carburetors and the exhaust and inlet manifold joints. It is unnecessary
continually to check these for tightness, once they are properly tightened
they require little or no attention. The unit tradesman should undertake this
task.
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Note:
Over tightening will NOT cure defective gaskets.
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(b)
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Care
should be taken when replacing sparking plugs particularly the small type
plug that under force is not used otherwise the plug will be damaged.
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(c)
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When
it is necessary to tighten the exhaust manifold nuts under force should not
be used otherwise damage to the studs will result. Only the spanner provided
for a particular nut or bolt should be used.
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Water – tight joints
35. This normally entails keeping the clips
securing the hose connections and nuts securing flanges tight.
Oil –tight joints in engine
36. External oil joints usually take the form of
a flanged joint or a union and nipple. In the case of the former, Special oil
resisting jointing or cork sheet is used, the oil tight joint being obtained by
tightening the flange securing the joint. Oil tight joint which requires
watching for leaks are:-
(a)
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Sum
joints.
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(b)
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Sump
drain joints.
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(c)
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Timing
case joint.
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(d)
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Rocker
cover.
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(e)
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Tappet
cover.
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Oil filters
37. Maintenance of oil filters necessitates
periodical draining of the filter to remove sediment and periodical dismantling
of the filter to clean the elements. The nature of the work is dependent on the
type of filter used and instruction books or service instructions should be
followed. OIL FILTER ELEMENTS MUST BE
CHANGED AT THE FREQUENCY LAID BY MAKERS.
Injector Pump and Injectors
37. Injector
Pump
The
injector pump and injectors must not be dismantled or interfered with in any
way by drivers.
39. Maintenance in the unit comprises the
following:-
(a)
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Ensure that there are no leaks from the injector pump
or from the fuel pipes and unions between the injector pump and the injectors.
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(b)
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The oil in the
injector pump sump must be kept to the level on the dip stick. This should be
checked and topped up every month.
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(c)
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Oil level in the governor should be checked every month
and topped up if necessary.
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(d)
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Inspect the securing bolts and tighten if necessary.
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(e)
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Adjustment of slow running and uneven firing at low
speeds. Tradesman will adjust this only. Any defects will be reported for
attention.
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40. Filters
(a)
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Fuel
ore-filters will be cleaned every 3,200 kilometer with the help of unit
tradesman.
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(b)
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Twin fuel Filter
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i
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Every1,600 Kms, fuel will be drained
through plug (If fitted) till clear fuel flows.
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ii
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Every
3,200 Km, primary stage filter element will be cleaned and final stage filter
element replaced.
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External Parts
41. Lubrication of external parts comprises
lubricating the controls which only require an occasional drop of oil on joints.
Nuts and Bolts
42. These should be kept securely tightened at
all times. The operator will normally attend to all nuts and bolts that are not
fitted with split pins with the exception of cylinder head bolts. Where nuts
are split-pinned these will be attended to by unit tradesman or workshop
mechanics. Nuts and bolts will only be tightened as far as possible with the
standard spanner for the nut. Box spanners used in conjunction with
double-ended spanners to obtain additional leverage will not be used. Care
should be exercised when tightening bolts securing flexible engine mountings.
These should be firmly bolted but not over–tightened. These will be attended to
by unit tradesman or workshop mechanics.
Maintenance of Ignition system
43. Maintenance
by the operators – Sparking plugs
(a)
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Keep
the plugs tight in the engine. Do not use undue force in tightening,
particularly with the smaller type plug i.e, 14 and 10 mm size.
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(b)
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Keep
the insulator clean, dry and free from oil or grease.
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(c)
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Dismantle
plug and clean, if necessary. Ensure washer is replaced on plug when
assembling.
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(d)
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Adjust points, to the
gaps specified in the maintenance manual. (This will be done by EME or unit
tradesman).
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(e)
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Replace
unserviceable terminal clips, copper and asbestos washers.
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44. High
tension leads
(a)
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Keep
the terminal tight.
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(b)
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Keep
the leads dry and free oil grease.
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(c)
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Secure
leads away from hot parts or engine, or where dubbing may cause leads to fray.
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(d)
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Wrap
frayed, burnt, or cracked insulation with insulation taps and report for
renewal or lead as soon as possible.
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45. Coil
and distributor
(a)
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Keep
clean and free from oil.
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(b)
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Keep
all nuts, screws and terminals tight.
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(c)
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Examine low tension
leads for defective insulation rectify if necessary with insulation tape,
report early for replacement of leads.
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46. Maintenance
of Batteries
One of the most important points
affecting the satisfactory operation of equipment is the condition of the
battery. It is the foundation of the electrical system and if not in perfect
condition will affect the economic operation of the equipment.
47. The systematic check of the battery is of
the greatest importance and the operator should carry this out once a week.
48. The following procedure for battery
maintenance should be followed: -
(a)
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Clean
the top battery, to remove dirt that might drop into the cells when the vent
caps are removed.
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(b)
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Remove
caps and place them upside down on the side of the battery.
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(c)
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Check
level of electrolyte in battery and add distilled water is necessary. The
level of the electrolyte should be ¼” above the plates. Examine battery for
leaks.
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(d)
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Examine
battery connections. Wipe away any signs of corrosion around the terminals
with a wet cloth. If terminals have corroded to the extent that the metal has
been eaten away report for replacement. Ensure that connections are not
loose, not overlooking the earth connections. Liberally smear the terminals
with lanoline or petroleum jelly. If not available leave perfectly dry.
GREASE WILL NOT BE USED UNDER ANY CIRCUMSTANCES.
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Maintenance of Tyre Equipment and
wheels (Every 2000 Miles)
(Refer General Maintenance Instruction
No. 4 also)
49. Tyre
(a)
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The
precaution to be observed to prolong the ‘life’ of tyres are given below:-
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(i)
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Avoid violent braking.
|
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(ii)
|
Avoid violent acceleration.
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(iii)
|
Reduce speed when turning corners.
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(iv)
|
Avoid curb-stones.
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(v)
|
Careful driving over freshly laid
and up rolled gravel and road metal. When traveling over such surfaces the
vehicle should be driven at the driven at the lowest possible speed.
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(b)
|
The importance of correct tyre
pressure cannot be over stressed. Operators will check daily tyre pressures
with the pressure gauge. Correct tyre pressures are painted on the mud wings
or on the body above each tyre.
|
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(c)
|
Operators should periodically
examine tyres for bad cuts, nails and embedded stones. Nails and stones.
Should be removed as they tend to cause further damage to tyres. Severe cuts
should be reported.
|
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(d)
|
In order to ensure that all tyres
wear evenly, tyres including spare wheel, these should be changed over
periodically as per the reference given in the log books.
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(e)
|
In the event of a
burst of tyre of puncture drivers should bring the vehicle to a standstill
slowly and not by the vigorous application of brakes. In the case of Run flat
tyres only in an emergency will drivers continue to drive the vehicle with a
flat tyre.
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||
(f)
|
Tyres should be
replaced before they reach the limit of wear at which re treading is not
possible, i.e, when the depth of the tread pattern at the crown of the tyre
is approximately 1/8” in depth.
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(g)
|
Tar, oil and grease
are also harmful to tyres, and care must be taken to prevent tyres becoming
contaminated with these substances.
|
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(h)
|
The painting of the
walls of tyres with white oil based paint for ceremonial is strictly
prohibited.
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50. Tubes
When tubes are issued as spare, they
will be very slightly inflated, dusted with French chalk and carried in such a
way that they are not damaged by coming into contact with other items of
equipment.
51. Wheels
(a)
|
Ensure
that wheels are always tight, and that wheel nuts are tightened up evenly.
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(b)
|
Use only the correct
tools for removing and re-fitting tyres.
|
(c)
|
Report
severe dents in wheel rims or buckled wheels.
|
(d)
|
Once
every six months remove tyres and treat rim with paint black Anti-Corrosive
Acid and Alkali Resisting.
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52. Well
base rims
Wheels with well base rims are used
extensively on light vehicles and generally in conjunction with wire wheels.
When the tyre is removed from the rim, drivers should check for points (c) and
(e) above.
53. Detachable
clinch tyre or three piece wheel
These are used extensively on heavy
vehicles in conjunction with the normal tyre equipment. The wheel assembly
comprises the following parts: -
(a)
|
A “Flange” or ‘Fined Clinch” fitted
on one edge of the rim.
|
(b)
|
The flat base of the wheel disc
proper, over, which the tyre fits closely
|
(c)
|
A detachable flange which slides
over the un flanged portion of the rim. This is held position by a spring
ring.
|
(d)
|
After the tyre is assembled on the
detachable flange, which is held in position by the split ring, locate the
tyre in position on the rim.
|
(e)
|
Operators should pay particular
attention to the flat surfaces of the rim. This should be kept clean and
treated with graphite. Considerable difficulty will be experienced in
removing and re-fitting tyres if rims are allowed to rust.
|
54. Two
pieces or dividable wheels
(a)
|
Certain vehicles are
fitted with two-piece wheeler Each wheel comprises two halves, which when
fitted to a tyre are clamped together by special studs and nuts. These
special studs and nuts are in addition to the studs and nuts, which hold the
wheel on to the hubs.
|
(b)
|
To remove the outer
cover from the wheel it is first necessary to remove the complete wheel from
the hub by unscrewing the inner circle of nuts. Removing the valve core
should then deflate the tyre. The outer ring of nuts should then be removed
and the two halves of the rims separated. It will be necessary to use the
special tools provided for this purpose and the instructions for their use
should be strictly followed.
|
(c)
|
When assembling the
tyre must not be inflated until the two halves of the rim have been tightly
bolted together.
|
(d)
|
The special nuts for
holding the two halves of the rim together are painted red. It is of greatest
importance that the tyre be deflated before these nuts are removed otherwise
the air pressure in the tyre will below the rims apart with the possibility
of a serious accident.
|
55. Maintenance
of Tracks
(a)
|
Inspect
and tighten, loose bolts, nuts, cap screws, on track roller brackets guard
nuts, track adjustment spring cover bolts.
|
(b)
|
Check
for damage to grease fittings and replace where necessary.
|
(c)
|
Check for damage to idler rollers.
|
(d)
|
Examined
for excessive wear of link pins and broken track chain.
|
(e)
|
Check
track tension, and adjust if necessary.
|
56. Maintenance
of Compressors
Compressors are very important
construction equipments. The following maintenance tasks will be carried out
every week:-
(a)
|
Check
the compressed air line and joints and ensure that there is no leaking.
|
(b)
|
The
air pressure gauge, oil pressure gauge and safety valve will be checked for
its marking every day.
|
(c)
|
The
air filter element will be checked and changed for suction of dust free air.
|
(d)
|
The
mounding bolts of the compressor and the cylinder head should be checked by
unit tradesman for its tightness and serviceability of pad/gasket.
|
(e)
|
Correct
lubricating oil will be used and changed at specified hours.
|
57. POINTS
FOR MAINTENANCE IN EXTREME COLD WEATHER
In principle, the care and maintenance
of equipment should be carried out in the same manner as would be done under
normal environments. But the extreme cold weather conditions warrant that
special importance is given to certain existing points for maintenance and that
certain additional precautions are observed to combat the peculiar conditions.
These points are detailed in the following paragraphs.
58. Washing
and Cleaning
Though general cleanliness is
imperative, never spray water on equipment outdoors when the temperature is
below the freezing point Even when water can be sprayed in a heated room or
shelter, the equipment must be dried off before it is taken outdoors. After the
equipment is dried out externally, it must be driven over a short distance with
frequent application to brake and clutch, so the any water that would have
found access to these components is squeezed dried out before it has a chance
to freeze.
59. In case general washing of the equipment
cannot be done, loose snow and dirt should be brushed off. Do not knock off ice, as this will damage the
paintwork underneath. However, ice must
be scrapped off the glass panels, driving mirrors, number plates etc.
60. Dry cleaning of the equipment, particularly
of components, which gets warmed up during a run, must be done when these are
still warm after the run.
Cooling system
61. Water in the cooling system will freeze when
sub zero temperatures are encountered. Anti-freeze as indicated in the
succeeding para should be used.
62. A solution containing 45% of Ethylene Glycol
is to be used for temperature up to minus 35oC (minus 310;
below this temperature this solution must have 60% Ethylene Glycol. These
ratios must be strictly adhered to.
Caution: An increase in the proportion of Ethylene Glycol beyond
its “Eutectic” composition will only result in a higher freezing point of the
coolant. Undiluted Ethylene Glycol freezes at minus 120 C (Plus 100F)
only.
63. Frozen radiators, and failure of the engine
to reach normal operating temperatures are the two most common failures in sub
zero operation. If instructions for the use of anti-freeze are scrupulously
observed, radiator freezing will not occur. However, should this happen the affected
vehicle will be placed in a heated shelter, or covered and heated until the
coolant thaws. Under no circumstances will the engine be started until the
frozen radiator has thawed. If on starting an engine, a sudden rise in
temperature is recorded by the temperature gauge, a frozen radiator can be one
of the causes. In such a case; therefore, the engine should be switched off
immediately and the condition of coolant checked.
64. Failure of engine to reach its normal
operating temperature may be due to maladjustment of the Radiator Muff. To
rectify this check the Bonnet cover and Radiator Muff for correct adjustment,
fitting and state if serviceability. Torn or damaged covers or muffs must be
repaired or replaced immediately. If despite this, the correct operating
temperature is not reached, report to the dependent Field Workshop.
Fuel system
65. Successful operation of equipment at
extreme-low temperature will depend, to a large extent, on the condition of the
fuel used. Water in engine fuel causes serious difficulties. Even at
temperature a little above the freezing point of water, the water content in
fuel can form ice ground the throttle valve and in the jet of the carburetor.
This would obstruct the passage of fuel through the carburetor. It is thus, essential
that the fuel used be completely free from water. The following precautions
must therefore, be implemented.
(a)
|
Caps
of fuel containers will be kept tightly closed to prevent ingress of snow,
ice or dirt.
|
(b)
|
Wipe
off all snow around filter caps of fuel through a chamois skin to prevent
passage of water.
|
(c)
|
When
topping up fuel tank, strain the fuel through a chamois skin to prevent
passage of water.
|
(d)
|
Fuel
tanks will be topped up every day after day’s work. This drill become more
important at low temperatures since it minimizes fuel tanks “Breathing” and
the resultant moisture condensation over –night. If trouble is still
encountered due to formation of ice in the fuel system, mix 1% Methyl Alcohol
with fuel at the time of refueling.
|
Lubrication system
66. It is possible that due to various factors
rapid sludge formation in the engine oil may be experienced in certain areas.
The condition of the engine oil must, therefore, be checked frequently when
equipments are operated at low temperatures. In case of doubt the advice of
maintenance Field Workshop must be sought.
67. In LADAKH particularly dust contamination of
the lubricating oil will be more repaid due to the extreme dustiness of the
terrain. The periodicity of oil change
has, therefore, to be increased. Whist
the extent of this increase in various sectors will be specified by the Dir
EME/SO 1), the following increases may be used as a rough guide.
(a)
|
Engine
oil
|
:
|
At
half the mileage in normal terrain.
|
(b)
|
Transmission
oil
|
:
|
At
75% of the mileage in normal terrain.
|
68. Other precautions necessary to ensure proper
lubrications are as follows:-
(a)
|
Check air cleaners frequently for
proper functioning. Clean or replace elements and oil at specified
frequencies, and whenever a neck reveals necessity for cleaning or
replacement.
|
(b)
|
Carry out chassis lubrication only
immediately after a run.
|
(c)
|
If heating of greasing points
becomes necessary to facilitate re greasing, this should be done by bathing
the affected part in hot water with the help of rages. Lubrication moreover,
would be facilitated, if the grease gun in kept in a heated place e.g the
engine compartment. Heating of grease points with direct flame should never
be done. Rapid heating decomposes the grease which then becomes
unserviceable. This also damages grease nipples resulting in inability of the
valves to seal the grease which has been. pumped in
|
Electrical system
69. One of the major problems affecting the case
of starting an equipment in extreme cold arises from the fact that the batter
is called upon to withstand heavier loads at a time when the battery capacity
is materially reduced by low temperatures.
Care and maintenance of battery, therefore, gains added importance at low
temperature. Besides normal maintenance,
it is essential that precautions detailed below are meticulously absorbed: -
(a)
|
The
specific gravity of each cell must be checked before starting every day at
atmospheric temperatures, below OOC.
|
||
(b)
|
In
case the level of electrolyte is found to be lower than the correct level,
water should never be added to a cold battery; add the water only when the
battery is warm and is being charged.
Distilled water may, therefore, be added after the equipment has been
run for some time and the battery has warmed up and is receiving charge. If water is added to a cold battery at sub
zero temperatures, which is not under charge, the layer of water will stay at
the top and freeze before it has a change to mix with the acid.
|
||
Caution
|
:
|
If
water is added to a battery between temperatures of plus 32O to
plus 50O F, do not fill to the normal level since the electrolyte
will expand as it gets heated, and the battery will flood. At these temperatures top up the battery
only to the level of the top edge of the plates.
|
|
Parking of Vehicles
70. Equipments may have to be parked or garaged
outdoors out of necessity. This exposes
them to the effect of wind-chill and service cold. This makes it all the more imperative that
certain precautions are observed before parking. These precautions will also facilitate re-use
of the equipments after over-night parking.
(a)
|
To ensure that wheel tyres and
tractor-tracks do not freeze to the ground, equipments will be run up on to a
prepared bed to tree branches or planks or even paper. It is particularly important that if
parking in water or sludge cannot be avoided, the wheels must be placed on a
bed of tree branches or the like. If
prolonged periods of idleness are envisaged vehicles must be moved a little
once a day. This may not be possible
for non-runner tractors but it should always be possible for soft equipments.
|
(b)
|
The cooling system of equipment is
so designed that it can emit heat quickly.
Consequently, after the engine has been stopped, it quickly cools down
to the temperature of the outside air.
My covering up the engine and setting up screens against the prev
ailing wind, this cooling can be restricted considerably.
|
(c)
|
Parking brakes should not be left in
“no” position.
|
(d)
|
If a prolonged period of idleness is
envisaged, the clutch should be left in disengaged. position.
|
(e)
|
Batteries should preferably be
stored in living accommodation. This
is particularly important if the battery is not likely to be out to use for a
few days.
|
(f)
|
With a view to use the engine as a
brake, coming down an inkling must be accomplished in the same gear as would
have been necessary for going up that incline. Using the brakes only t control the speed
results in fading away of the brakes in a very short time, and involves the
danger of skidding on slippery surfaces.
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