4-33
Fault
Reason
Solution
12. Hydraulic oil temperature
is high
• Wrong use of hydraulic oil
• Use the correct hydraulic oil
• Oil path blocked
• Consult the company's agent
• Hydraulic oil filter is blocked
• Clean or replace
• Oil pump wear
• Consult the company's agent
• Oil cooler blocked
• Clean oil cooler
• Oil cooler failure
• Consult the company's agent
• The pressure for the main safety valve or the relief valve
of rotary system is too high
• Consult the company's agent
• The oil is too dirty
• Oil change
• Sensor failure
• Replace
13. The hydraulic oil is
emulsified or has foam
• The pipeline leaks from the fuel tank to the fuel pump
• Overhaul and tighten
• Wrong use of hydraulic oil
• Use the correct hydraulic oil
• Hydraulic oil contains water
• Oil change
• The oil level is too low
• Calibration of oil level
14. The oil pressure is too
low or there is no pressure
• The hydraulic pump is damaged
• Consult the company's agent
• Insufficient oil in the system
• Refill the fuel
• Safety valve failure
• Consult the company's agent
15. All parts can't work
• The hydraulic pump is damaged
• Consult the company's agent
A. The oil pump makes noise
• Lack of hydraulic oil
• Refill the fuel
• Air leakage in the suction pipe
• Repair or replace
B. The noise of the oil pump
remains unchanged
• The auxiliary pump is damaged
• Replace
• The hydraulic safety control device does not work
• Inspection and repair
16. The cylinders or motors
are weak or not working
• The hydraulic pump is damaged
• Consult the company's agent
• Main safety valve pressure becomes lower
• Re-adjust the pressure
• Low oil pressure and oil level
• Refill the fuel
• Oil suction filter is blocked
• Clean the oil filter
• Oil seal is damaged
• Repair or replace
• Damaged piston rod causes oil leakage
• Repair or replace
• Pilot valve failure
• Replace
• The pilot pipe is broken or leaking oil
• Repair or replace
17. Two walking devices do
not work
• Central rotary joint oil flushing
• Consult the company's agent
18. A walking device does not
work
• The walking device is damaged
• Consult the company's agent
• The control mechanism is damaged
• Overhaul
Summary of Contents for U27
Page 1: ...U27Hydraulic Excavator Instruction Manual Guangxi Yuchai Heavy Industry Co Ltd...
Page 5: ...1 1 Preface...
Page 17: ...2 1 Safety regulations...
Page 44: ...3 1 Parts introduction...
Page 49: ...3 6 Panel meter Oil level pointer Timing display Water temperature pointer Indicator area...
Page 55: ...4 1 Operation guide...
Page 89: ...5 1 Maintenance...
Page 130: ...6 1 Accessories guide...