4-31
Causes of technical failures and solutions
Fault
Reason
Solution
1. The engine cannot start
or is difficult to start
• There is a problem with the starter motor
• Replace or overhaul the starter motor
• Insufficient battery charge
• Charge or replace with a new battery
• Improper use of preheating circuit or glow plug
• Repair or replace the glow plug
• Incorrect injection timing
• Check the injection timing
• Oil pipeline is blocked
• Clean oil circuit
• The fuel filter is blocked
• Clean or replace the fuel filter
• The fuel system has water, dust or air
• Discharge air and clean oil circuit
• Dirty nozzle or low injection pressure
• Go to the local repair point for repairs
• Failure of fuel injection pump
• Consult the company's agent
• Insufficient fuel
• Refill the fuel
• The intake and exhaust systems are blocked
• Unblocked intake and exhaust systems
2. The engine knocks, runs
irregularly or shuts down
• Large blow-by gas
• Consult the company's agent
• The fuel filter is blocked
• Clean the filter
• There is dirt or air in the fuel system
• Discharge air and clean oil circuit
• Oil filter is blocked, nozzle is dirty or faulty
• Go to the local repair point for repairs
• Damaged high pressure oil pipe
• Replace the high pressure oil pipe
• Insufficient fuel
• Refill the fuel
• The governor connection cannot be adjusted
• Consult the company's agent
• Failure of fuel injection pump
• Consult the company's agent
• Incorrect fuel injection timing or fuel injection
nozzle stuck
• Check fuel injection timing and fuel nozzle
3. Engine power drops
• The fuel is mixed with air
• Discharge air
• The oil supply is not smooth
• Check and clean
• Injection timing changes
• Adjust according to the specified value
• The injector is not working well
• Check the working pressure and atomization of fuel
injection
• Air filter is blocked
• Clean the filter element.
• Wrong intake and exhaust valve clearance or valve
is not sealed
• Adjust valve clearance
• Cylinder gasket is broken and leaking
• Replace the cylinder gasket
• Poor operation of fuel injection pump
• Consult the company's agent
• The engine is overheated
• Check whether the coolant used is correct. Whether
the water pump and belt are too loose, repair or
replace if there are any, and remove the obstruction of
the water channel
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...