Doosan 7/26E, Operation And Maintenance Manual

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MAINTENANCE 25
7/26E, 7/31E, 7/41
Alternator/drive belt failure circuit.
At twelve month intervals test the alternator drive belt failure circuit as
follows:
• Remove the drive belt from the machine.
• Turn the key switch to position 1, the alternator charge light will
illuminate.
• Turn the key switch to position 3 (engine start position).
• The machine should shutdown when the key switch is returned to
position 1.
SCAVENGE LINE
The scavenge line runs from the combined orifice/drop tube in the
separator tank, to the orifice fitting located in the airend.
Examine the orifice, check valve and hoses at every service or in the
event of oil carryover into the discharge air.
It is good preventative maintenance to check that the scavenge line
and tube are clear of any obstruction each time the compressor
lubricant is changed as any blockage will result in oil carryover into the
discharge air.
COMPRESSOR OIL FILTER
Refer to the MAINTENANCE CHART in this section for the
recommended servicing intervals.
Removal
Clean the exterior of the filter housing and remove the spin-on element
by turning it in a counter-clockwise direction.
Inspection
Examine the filter element.
Reassembly
Clean the filter gasket contact area and install the new element by
screwing in a clockwise direction until the gasket makes contact with
the filter housing. Tighten a further
1
/
2
to
3
/
4
of a revolution.
COMPRESSOR OIL SEPARATOR ELEMENT
Normally the separator element will not require periodic maintenance
provided that the air and oil filter elements are correctly maintained.
If, however, the element has to be replaced, then proceed as follows:
Removal
Disconnect all hoses and tubes from the separator tank cover plate.
Remove the drop-tube from the separator tank cover plate and then
remove the cover plate. Remove the separator element.
Inspection
Examine the filter element. Examine all hoses and tubes, and replace
if necessary.
Reassembly
Thoroughly clean the orifice/drop tube and filter gasket contact area
before reassembly. Install the new element.
For 7/26E and 7/31E models, replace element O-ring in every
reassembly.
Reposition the cover plate, taking care not to damage the gasket, and
replace the cover plate screws tightening in a criss-cross pattern to the
recommended torque (refer to the
TORQUE SETTING TABLE later in
this section).
Engage the adaptor in the cover plate with the drop-tube integral with
the filter, reconnect all hoses and tubes to the separator tank cover
plate.
Replace the compressor oil (refer to LUBRICATION later in this
section).
COMPRESSOR OIL COOLER AND ENGINE RADIATOR
When grease, oil and dirt accumulate on the exterior surfaces of the oil
cooler and radiator, the efficiency is impaired. It is recommended that
each month the oil cooler and radiator be cleaned by directing a jet of
compressed air, (carrying if possible a non-flammable cleaning
solvent) over the exterior core of the cooler/radiator. This should
remove any accumulation of oil, grease and dirt from the exterior core
of the cooler so that the entire cooling area can radiate the heat of the
lubricating and cooling oil/water into the air stream.
WARNING: Do not remove the filter(s) without first making sure
that the machine is stopped and the system has been
completely relieved of all air pressure. (Refer to
STOPPING THE
UNIT in the OPERATING INSTRUCTIONS section of this
manual).
CAUTION: If there is any indication of the formation of varnishes,
shellacs or lacquers on the filter element, it is a warning that the
compressor lubricating and cooling oil has deteriorated and that it
should be changed immediately. Refer to LUBRICATION later in this
section.
CAUTION: Start the machine (refer to PRIOR TO STARTING and
STARTING THE UNIT in the OPERATING INSTRUCTIONS section
of this manual) and check for leakage before the machine is put back
into service.
WARNING: Do not remove the filter(s) without first making sure
that the machine is stopped and the system has been complete-
ly relieved of all air pressure. (Refer to
STOPPING THE UNIT in
the OPERATING INSTRUCTIONS section of this manual).
WARNING: Do not remove the staple from the anti-static gasket
on the separator element since it serves to ground any possible
static build-up. Do not use gasket sealant since this will affect
electrical conductance.
CAUTION: Start the machine (refer to PRIOR TO STARTING and
STARTING THE UNIT in the OPERATING INSTRUCTIONS section
of this manual) and check for leakage before the machine is put back
into service.
WARNING: Hot engine coolant and steam can cause injury.
When adding coolant or antifreeze solution to the engine radia-
tor, stop the engine at least one minute prior to releasing the ra-
diator filler cap. Using a cloth to protect the hand, slowly release
the filler cap, absorbing any released fluid with the cloth. Do not
remove the filler cap until all excess fluid is released and the en-
gine cooling system fully depressurised.
WARNING: Follow the instructions provided by the antifreeze
supplier when adding or draining the antifreeze solution. It is
advisable to wear personal protective equipment to prevent skin
and eye contact with the antifreeze solution.