Common Malfunctions And Repair Methods For Motor Graders
The common malfunctions of motor graders mainly occur in the blade system, hydraulic system, braking system, and transmission. I have compiled the corresponding repair methods and preventive measures for you.
Blade system malfunctions usually manifest as excessive wear, deformation, or adjustment failure. Repairs involve replacing worn blades or straightening deformed parts, and checking the hydraulic cylinder seals. Before daily operation, be sure to clear the work area of hard objects and avoid overloading the machine.
Hydraulic system malfunctions often present as oil leaks, sluggish operation, or excessive oil temperature. Focus on checking the hydraulic pump, oil lines, and seals, and promptly replace contaminated or insufficient hydraulic fluid. Weekly checks of oil level and quality, and keeping the radiator clean are crucial.
Braking system malfunctions may be caused by insufficient brake fluid, worn brake discs, or valve damage. Regularly check the brake pad thickness, clean the oil lines, and ensure the brake fluid level and quality meet specifications.
Lack of pressure in the transmission usually stems from hydraulic pump failure, internal leakage, or pressure control valve malfunction. The hydraulic system needs to be inspected, damaged seals or the oil pump replaced, and the pressure control valve checked.
How to repair a grader engine malfunction?
When troubleshooting engine problems in a grader, you need to consider the specific symptoms. If the engine is difficult to start, first check if the battery is fully charged, if the fuel filter is clogged, and if there is air in the fuel line. If the oil pressure is abnormal, check if the oil level is sufficient and if the oil filter is clogged. If the water temperature is too high, check if there is enough coolant and if the thermostat is working properly.
For a non-starting engine, troubleshooting points include: battery condition, starter motor, fuel system (fuel level, fuel quality, filter), electrical connections, and whether any engine mechanical components are seized. Insufficient power may stem from low boost pressure, air leaks or blockages in the intake manifold, or a clogged fuel filter.
Regular maintenance is crucial. Regularly changing the engine oil and oil filter, cleaning the air filter, and checking and tightening all engine components can effectively prevent malfunctions. For complex problems, it is recommended to contact professional repair personnel.
How to determine if an engine needs a major overhaul?
To determine if a grader engine needs a major overhaul, consider these key indicators:
- Power Performance:
If the grader’s power output significantly decreases during operation, acceleration is sluggish, and climbing hills is difficult, even with increased throttle, this usually signals severe internal engine wear.
- Oil Consumption and Exhaust:
Abnormally increased oil consumption, blue smoke from the exhaust pipe (burning oil), or thick black smoke (incomplete combustion) may indicate wear on components such as piston rings, cylinder walls, or valve stem seals, requiring close attention.
- Abnormal Noises:
Unusual metallic knocking sounds from the engine, such as cylinder knocking or bearing noises, are often clear warnings of severe wear or damage to internal parts and require immediate inspection.
- Cylinder Wear:
Cylinder out-of-roundness (wear exceeding 0.125 mm per 100 mm of cylinder diameter) or conical wear (exceeding 0.40 mm per 100 mm of cylinder diameter) are important quantitative standards for determining the need for a major overhaul.
- Overall Operating Condition:
In addition to the engine itself, a grader’s major overhaul also requires a comprehensive assessment of the overall condition of the transmission, drive mechanism, and other assemblies.
Paying attention to these indicators daily and addressing any abnormalities promptly can effectively prevent greater losses.
How to prevent premature wear of grader engines?
Preventing premature wear of the grader engine hinges on regular inspection and replacement of the “three filters” (air filter, oil filter, and fuel filter), and ensuring that the engine oil and coolant are in good condition.
Engine oil and filters are the “blood” and “kidneys” of the engine. It is crucial to regularly change the engine oil and oil filter to remove suspended contaminants. When choosing engine oil, fully synthetic oil offers superior performance and a longer replacement interval, providing lasting protection for the engine.
The cooling system is vital for maintaining the engine’s “temperature.” Regularly check the coolant level and quality, ensuring its concentration meets requirements, and inspect the pipes and radiator for leaks or blockages to prevent engine overheating.
The air filter is the engine’s “mask.” Regularly check its resistance; if it exceeds the specified value or the indicator alarms, it must be replaced immediately to prevent dust from entering and causing wear.
In addition, the fuel system also needs regular cleaning to prevent carbon buildup; the crankcase ventilation system must be kept in good condition to prevent oil overheating and carbon deposits; and driving habits should avoid sudden acceleration, sudden braking, and prolonged high-load operation.