Doosan 7/71 - Fault Finding

FAULT FINDING
35
7/71, 12/56
FAULT CAUSE REMEDY
Engine fails
to start.
Low battery
charge.
Check the fan belt tension, battery
and cable connections.
Bad earth
connection.
Check the earth cables, clean as
required.
Loose
connection.
Locate and make the connection
good.
Fuel
starvation.
Check the fuel level and fuel
system components. Replace the
fuel filter if necessary.
Relay failed. Replace the relay.
Engine control
not in ’run’
position.
Check the speed cylinder and stop
position.
Engine
starts but
Electrical fault Test the electrical circuits.
starts but
stalls when
the switch
Low engine oil
pressure.
Check the oil level and the oil
filter(s).
the switch
returns to
position I.
Faulty relay Check the relays.
position I
.
Faulty
key−switch
Check the key−switch.
Engine
starts but
Electrical fault. Test the electrical circuits.
starts but
will not run
or engine
Low engine oil
pressure.
Check the oil level and oil filter(s).
or engine
shuts down
prematurely.
Safety
shut-down
system in
operation.
Check the safety shut-down
switches.
Fuel
starvation.
Check the fuel level and fuel
system components. Replace the
fuel filter if necessary.
Switch failure. Test the switches.
High
compressor oil
temperature.
Check the compressor oil level and
oil cooler. Check the fan drive.
Water present
in fuel system.
Check the water separator and
clean if required.
Faulty relay. Check the relay in the holder and
replace if necessary.
Engine
Overheats.
Reduced
cooling air
from fan.
Check the fan and the drive belts.
Check for any obstruction inside
the cowl.
Engine
speed too
high.
Incorrect
throttle arm
setting.
Check the engine speed setting.
Faulty
regulator
valve.
Check the regulation system.
FAULT CAUSE REMEDY
Engine
speed too
low.
Incorrect
throttle arm
setting.
Check the throttle setting.
Blocked fuel
filter.
Check and replace if necessary.
Blocked air
filter.
Check and replace the element if
necessary.
Faulty
regulator
valve.
Check the regulation system.
Premature
unloading.
Check the regulation and the
operation of the air cylinder.
Excessive
vibration.
Engine speed
too low.
See ”Engine speed too low”
Refer also to the engine section of this manual.
Air
discharge
capacity too
Engine speed
too low.
Check the air cylinder and air
filter(s).
capacity too
low.
Blocked air
cleaner.
Check the restriction indicators and
replace the element(s) if
necessary.
High pressure
air escaping.
Check for leaks.
Incorrectly set
regulation
system.
Reset the regulation system. Refer
to SPEED AND PRESSURE
REGULATION ADJUSTMENT in
the MAINTENANCE section of this
manual.
Compressor
overheats.
Low oil level. Top up the oil level and check for
leaks.
Dirty or
blocked oil
cooler.
Clean the oil cooler fins.
Incorrect
grade of oil.
Use Doosan recommended oil.
Recirculation
of cooling air.
Move the machine to avoid
recirculation.
Faulty
temperature
switch.
Check the operation of the switch
and replace if necessary.
Reduced
cooling air
from fan.
Check the fan and the drive belts.
Check for any obstruction inside
the fan cowl.
Excessive oil
present in
the
Blocked
scavenge line.
Check the scavenge line, drop tube
and orifice. Clean and replace.
the
discharge
air.
Perforated
separator
element.
Replace the separator element.
Pressure in
the system is
too low.
Check the minimum pressure valve
or sonic orifice.