Common faults in the hydraulic system of pavers and Their causes and solutions

The failure of the hydraulic system of a paver is often the result of the combined influence of multiple factors. Therefore, before analyzing the fault, it is necessary to clearly understand the principle and characteristics of the entire hydraulic system, and then make a judgment based on the fault phenomenon. On the construction site, there is a shortage of both components and detection instruments. There are some tricks to find out the cause of the fault. The most commonly used methods are to reverse the components and remove the load, etc. If the fault of the component is reversed as well, it indicates that the component has a problem. If the load is removed, the fault will disappear and the problem will be understood. In conclusion, it is very necessary to purposefully and directionally gradually narrow down the scope of the fault, determine the faulty area, part or a specific hydraulic component, and strictly avoid random disassembly and repair. It is necessary to avoid the blindness of analysis, because the flow condition of the oil in the hydraulic pipeline, the movement of the internal parts of the hydraulic components, and the damage of the sealing parts, etc., are intangible and invisible. Statistics show that over 70% of the faults in hydraulic systems are directly or indirectly caused by improper maintenance or contamination of hydraulic oil. Therefore, maintaining the cleanliness of hydraulic oil and proper maintenance and care are of great significance.

Common causes of faults in hydraulic systems and simple troubleshooting methods:

Fault 1: Oil leakage or seepage in the fuel line

1. Causes: (1) The hose or steel pipe burst; (2) The steel pipe is not tight; (3) The seal is damaged or not installed properly; (4) The joint is not tightened or loose; (5) The hydraulic joint has bumps and scratches.

2. Troubleshooting methods: (1) Replace with new parts, (2) Grind and repair, (3) Update and tighten.

Fault 2: Excessive noise

1. Causes: (1) Air leakage in the pipeline; (2) Components or pipelines not fixed properly, causing vibration; (3) The oil level in the oil tank is too low; (4) The speed control valve or relief valve is unstable.

2. Troubleshooting methods: (1) Tighten the joint or replace the seal, (2) Clean or replace the valve, (3) Add hydraulic oil.

Fault 3: Insufficient pressure

Causes: (1) The opening pressure of the relief valve is too low or it is damaged; (2) The sealing parts are damaged; (3) There is air in the cylinder and pipeline; (4) The oil is too thin and has a large leakage; (5) The components are severely worn and have a large leakage.

2. Troubleshooting methods: (1) Increase the pressure of the relief valve or replace it with a new one; (2) Expel all the air; (3) Use the recommended grade of hydraulic oil; (4) Replace the sealing parts.

Fault 4: The oil temperature is too high

Causes: (1) Extremely hot weather, (2) Long-term overloading operation, (3) Clogged cooler or slow speed of the cooling fan.

2. Troubleshooting methods: (1) Increase zero cooling measures or suspend operation; (2) Shut down the machine for cleaning and maintenance of the cooler.

Fault 5: The oil pump does not produce oil

1. Causes: (1) The oil level in the oil tank is too low; (2) The coupling is broken; (3) The electro-hydraulic proportional valve is damaged; (4) The suction valve is not opened.

2. Troubleshooting methods: (1) Add oil to the required level; (2) Replace the coupling; (3) Inspect the proportional valve and open the oil suction valve.

Fault 6: The motor/cylinder does not operate or the operating speed is insufficient

1. Causes: (1) The pump has no oil, insufficient oil supply or the motor is damaged; (2) The diesel engine speed is low; (3) The solenoid valve malfunctions such as being stuck or the electromagnet is burned out; (4) The throttle plate is blocked; (5) The motor or cylinder seal is damaged; (6) Electrical or mechanical reasons; (7) The load is too heavy or the pressure of the relief valve is too low.

2. Troubleshooting methods: (1) Inspect or replace the pump, motor, and electromagnet; (2) Increase the diesel engine speed; (3) Inspect the electrical or mechanical parts; (4) Clear the throttle plate and replace the sealing parts; (5) Reduce the load or increase the pressure of the relief valve.

Fault 7: Damaged oil seals of the pump and motor and low oil replenishment pressure

1. Causes: (1) High return oil pressure of the shell,(2) Clogged oil suction filter element, insufficient oil suction,(3) Low oil level in the oil tank.

2. Troubleshooting methods: (1) Replace the filter element and resume operation after the oil temperature rises. (2) Add oil to the required level.

Fault 8: The hopper and the ironing plate fall down by themselves

Causes: (1) Malfunction of the solenoid valve, (2) Damage to the cylinder seal, (3) Poor sealing of the check valve.

2. Troubleshooting methods: (1) Disassemble and clean or replace the solenoid valve; (2) Replace the sealing parts.