Samsung 120-2 Excavator No Steering, Transmission, and Hydraulics Troubleshooting Gui

[MikePhua]

The Samsung 120-2 excavator is a powerful machine widely used in construction, excavation, and other heavy-duty applications. The machine is equipped with advanced hydraulic, steering, and transmission systems that enable smooth operation under challenging conditions. However, some users have reported issues with steering, transmission, and hydraulics, leading to a complete loss of functionality. This article will explore common causes for the loss of steering, transmission, and hydraulics in the Samsung 120-2 excavator and provide solutions for troubleshooting and repair.
Symptoms of the Problem
The main problems reported by users include:

1. No Steering Function
   The steering system of the excavator fails to operate, making it impossible to turn or change direction. The steering system does not respond to inputs from the operator, causing the excavator to remain stationary or unable to navigate the worksite.
   
2. No Transmission Function
   The excavator’s transmission system fails to engage, and the machine cannot move forward or backward. Regardless of throttle or oil pressure, the transmission system does not transmit power to the wheels.
   
3. Hydraulic System Failure
   The hydraulic system becomes inoperable, preventing the excavator from performing tasks such as digging, lifting, or manipulating the arm. Low hydraulic oil flow or pressure prevents the hydraulic actuators from functioning properly.
   

Common Causes of the Issue

1. Hydraulic Oil Problems
   One of the most common causes of hydraulic system failure is issues with the hydraulic oil. If the hydraulic oil is low, contaminated, or of poor quality, it can prevent the hydraulic pump from functioning properly, which affects the entire hydraulic system. The hydraulic oil level, quality, and the pump’s performance should be regularly inspected and maintained.
   
2. Hydraulic Pump or Electrical Control System Failure
   A failure in the hydraulic pump or its electrical control system can also cause the steering, transmission, and hydraulic systems to malfunction. When the hydraulic pump fails, the oil pressure cannot be maintained, and the necessary hydraulic flow cannot be supplied to the various components.
   
3. Clogged Hydraulic Lines or Valves
   Hydraulic lines or valves can become clogged with debris, dirt, or sludge, leading to poor oil circulation and system failure. If the hydraulic lines are blocked, oil cannot flow freely to the actuators, which can cause the steering and hydraulic systems to fail.
   
4. Electrical System Failure
   The Samsung 120-2 excavator uses an electrical control system to manage and monitor the operation of the steering and transmission systems. If there is a fault in the electrical system, such as a weak battery or a malfunctioning control module, the signals for controlling the hydraulic pump and steering system will not be sent, causing operational failure.
   
5. Low Hydraulic Oil Pressure
   Low hydraulic oil pressure can prevent the hydraulic pump from delivering adequate pressure to the system, leading to a lack of power for the steering, transmission, and hydraulics. Checking the pressure adjustment valve and ensuring there are no blockages in the hydraulic system is essential for restoring proper operation.
   

Troubleshooting Steps

1. Check Hydraulic Oil
   The first step is to check the hydraulic oil level and quality. If the oil is low or of poor quality, it should be replaced. Additionally, inspect the oil for contamination. If necessary, clean the hydraulic system and replace the contaminated oil to restore proper oil flow.
   
2. Inspect the Hydraulic Pump
   Measure the output pressure of the hydraulic pump to verify whether it is delivering sufficient pressure. If the hydraulic pump’s output is inadequate or unstable, it could be due to a fault in the pump or the electrical control system. Check the pump and its drive system for damage, and replace any faulty components as needed.
   
3. Check Hydraulic Lines and Valves
   Inspect the hydraulic lines and valves for any signs of leaks, blockages, or damage. Remove any debris or contaminants from the lines to ensure free flow of hydraulic fluid. Also, inspect the hydraulic valves to ensure they are operating correctly, directing fluid where needed.
   
4. Check the Electrical System
   Inspect the excavator’s electrical system, including the battery voltage, control module, and wiring. Make sure the battery is fully charged, and the control system is capable of sending signals to the hydraulic pump and steering mechanisms. If there are any issues with the electrical components, repair or replace them.
   
5. Test Hydraulic Oil Pressure
   Check the hydraulic oil pressure to ensure it is within the recommended range. If the pressure is too low, inspect the pressure adjustment valve and clean any filters or blockages that may be restricting fluid flow.
   

Maintenance Recommendations

1. Regular Hydraulic Oil Changes
   Follow the manufacturer’s recommendations for hydraulic oil changes. Clean hydraulic oil is essential for smooth system operation, so regularly check the oil quality and change it as necessary. Always use high-quality hydraulic oil to prevent contamination and excessive wear on components.
   
2. Regular Inspection of Hydraulic System and Lines
   Periodically inspect the hydraulic system, lines, and valves for any signs of wear, leaks, or blockages. Regular cleaning and preventive maintenance will ensure the system operates smoothly and prevent costly repairs.
   
3. Maintain the Electrical System
   Keep the electrical system in good condition by regularly checking the battery voltage, wiring, and control modules. Replace any faulty electrical components to ensure proper communication between the control systems and hydraulic mechanisms.
   
4. Avoid Overloading
   Overloading the excavator can put excessive strain on the hydraulic system, steering, and transmission. Always operate the machine within its specified weight capacity to prevent damage to the hydraulic pump, control systems, and transmission.
   

Conclusion
The Samsung 120-2 excavator’s loss of steering, transmission, and hydraulic functions can be caused by issues with hydraulic oil, the hydraulic pump, clogged hydraulic lines, electrical system failure, or low hydraulic oil pressure. By following the troubleshooting steps outlined above and conducting regular maintenance on the hydraulic system, electrical components, and oil levels, you can prevent these problems from recurring and ensure the excavator operates efficiently. Regular inspections and timely repairs will help keep the Samsung 120-2 excavator in top working condition and extend its operational life.