42
FAULT FINDING
7/20, P65
FAULT
CAUSE
REMEDY
Air discharge capacity
too low.
Engine speed too low.
Check the air cylinder and air filter(s).
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 discharge air.
Blocked scavenge line.
Check the scavenge line, drop tube and orifice. Clean and replace.
Perforated separator element.
Replace the separator element.
Pressure in the system is too low.
Check the minimum pressure valve or sonic orifice.
Safety valve operates.
Operating pressure too high.
Check the setting and operation of the regulator valve piping.
Incorrect setting of the regulator.
Adjust the regulator.
Faulty regulator.
Replace the regulator.
Inlet valve set incorrectly.
Refer to
SPEED AND PRESSURE REGULATION ADJUSTMENT
in the
MAINTENANCE
section of this manual.
Loose pipe/hose connections.
Check all pipe/hose connections.
Faulty safety valve.
Check the relieving pressure. Replace the safety valve if faulty.
DO NOT
ATTEMPT A REPAIR.
Oil is forced back into
the air filter.
Incorrect stopping procedure used
Always employ the correct stopping procedure. Close the discharge valve
and allow the machine to run on idle before stopping.
Faulty inlet valve.
Check for free operation of the inlet valve(s).
Faulty discharge check valve.
Remove the valve from the discharge pipe and check the operation.
Machine goes to full
pressure when started.
Inlet valve set incorrectly.
Refer to
SPEED AND PRESSURE REGULATION ADJUSTMENT
in the
MAINTENANCE
section of this manual.
Machine fails to load
when the load button is
pressed.
Faulty load solenoid.
Replace the solenoid. Check the electrical circuit by feeling for movement
whilst depressing the load button.
Summary of Contents for 7/20
Page 9: ...DECALS 7 7 20 P65 Engine oil drain Cold Start Procedure...
Page 18: ...16 GENERAL INFORMATION 7 20 P65 VARIABLE HEIGHT RUNNING GEAR FIXED HEIGHT RUNNING GEAR...
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