Bobcat E20 Two-Speed Solenoid Location and Troubleshooting

[MikePhua]

The Bobcat E20 is a compact, versatile mini-excavator designed for use in tight spaces, making it ideal for urban construction sites and residential projects. One of its notable features is the two-speed transmission, which allows operators to toggle between a high-speed and low-speed mode to optimize performance based on task requirements. However, like all machinery, the two-speed functionality can sometimes face issues, often linked to the solenoid responsible for controlling the speed shifts.
This article delves into the location and troubleshooting of the two-speed solenoid in the Bobcat E20. By understanding the function of this solenoid, the symptoms of a malfunction, and the steps for proper maintenance, operators can ensure the efficient operation of their machines.
Understanding the Two-Speed Solenoid Function
The two-speed solenoid in the Bobcat E20 is a critical component for the proper functioning of its dual-speed transmission. The solenoid, typically controlled by the machine’s electronic system, is responsible for engaging and disengaging the high and low-speed settings. It acts as an electromagnetic switch, responding to signals from the operator's control system.
When the solenoid functions properly, it allows the operator to seamlessly switch between the high-speed and low-speed modes. In high-speed mode, the machine moves faster, making it ideal for tasks like transport. Low-speed mode offers more torque and power, which is beneficial for digging and precise maneuvering in confined spaces.
Symptoms of a Faulty Two-Speed Solenoid
When the two-speed solenoid fails or malfunctions, the Bobcat E20 may experience various issues related to the transmission system. The most common symptoms of a faulty solenoid include:

1. Inability to Shift Speeds:
   • If the machine fails to shift between high and low-speed modes, it could be a sign that the solenoid is not engaging properly. This issue can significantly hinder the machine's performance, as it won’t be able to adapt to different worksite conditions.
     
2. Erratic Shifting:
   • The two-speed system might shift unexpectedly or fail to stay in the selected gear, causing unpredictable operation. This could make operating the machine challenging, especially when precise control is needed.
     
3. Lack of Response:
   • A lack of response when attempting to change speeds can indicate that the solenoid is stuck in one position or has failed completely.
     
4. Overheating:
   • A malfunctioning solenoid can lead to the overheating of the hydraulic system, as the machine may get stuck in high-speed mode without adequate cooling.
     

Locating the Two-Speed Solenoid in the Bobcat E20
The location of the two-speed solenoid in the Bobcat E20 can vary slightly depending on the model and year, but in general, the solenoid is located near the transmission or hydraulic pump system. Here’s how to locate and identify the solenoid:

1. Accessing the Engine Compartment:
   • Begin by lifting the engine cover or access panel of the Bobcat E20 to reach the rear of the machine where the hydraulic components are located.
     
2. Identify the Transmission Area:
   • The solenoid is typically positioned close to the transmission housing or within the hydraulic pump area. It is often attached to the valve body, which controls the flow of hydraulic fluid between the different gears.
     
3. Look for Wiring Connections:
   • The solenoid will have an electrical connection with wiring leading to the control system. This wiring is usually color-coded, so referring to the Bobcat E20’s service manual for wiring diagrams can help in locating it accurately.
     
4. Check the Control Valve Area:
   • In some cases, the solenoid can be found near the control valves that regulate hydraulic functions. Inspect the hydraulic lines running to and from this area to pinpoint the exact location.
     

Diagnosing and Troubleshooting the Two-Speed Solenoid
Once the solenoid has been located, it’s important to perform a few tests and inspections to diagnose potential problems. Here are some troubleshooting steps:

1. Inspect the Electrical Connections:
   • A loose or corroded electrical connection is often the culprit for solenoid failure. Use a multimeter to check the continuity of the wires and verify that the solenoid is receiving power. If there are any issues with the wiring, replace or clean the connections.
     
2. Check the Solenoid for Physical Damage:
   • Visually inspect the solenoid for any signs of wear, damage, or leaks. If the solenoid appears to be physically damaged, it will likely need to be replaced.
     
3. Test the Solenoid:
   • To test the solenoid itself, use a multimeter to check for resistance. The solenoid should have a certain resistance value when functioning properly. If the reading is out of range, the solenoid may be faulty and need to be replaced.
     
4. Test the Hydraulic System:
   • In some cases, the solenoid might appear to be working, but the hydraulic system may not be functioning correctly due to low fluid levels or a hydraulic leak. Check the fluid levels and inspect the system for leaks.
     
5. Check for Software Issues:
   • If the solenoid and hydraulic systems appear to be working fine but the two-speed function still isn't working, there might be an issue with the machine’s control software. Check for any error codes and clear them using a diagnostic tool. If needed, perform a software reset or update.
     

Solutions for a Faulty Two-Speed Solenoid
When a faulty solenoid is diagnosed, the solution is typically to replace the solenoid or repair any issues related to wiring or fluid flow. The following steps can help resolve the issue:

1. Replacing the Solenoid:
   • If the solenoid is confirmed to be faulty, replace it with a genuine Bobcat part. Ensure that the new solenoid is compatible with the Bobcat E20 model, as using the wrong part can cause further operational problems.
     
2. Rewiring or Cleaning Connections:
   • If the problem lies in the electrical connections, clean or replace the corroded wires. Ensure all connections are tight to avoid future issues.
     
3. Hydraulic System Maintenance:
   • Perform regular maintenance on the hydraulic system to avoid issues with pressure or fluid flow. This includes checking fluid levels, replacing filters, and inspecting hoses for leaks.
     

Preventative Maintenance for the Bobcat E20
To prevent issues with the two-speed solenoid and ensure long-term reliability, follow these maintenance tips:

1. Regularly Inspect the Solenoid and Wiring:
   • Make it a habit to check the solenoid and wiring connections during routine maintenance. Clean any dirt or debris and ensure that the wiring is secure and undamaged.
     
2. Hydraulic Fluid Maintenance:
   • Regularly change the hydraulic fluid and filters to keep the hydraulic system running smoothly. Contaminated fluid can damage the solenoid and other components.
     
3. Follow the Manufacturer's Service Schedule:
   • Bobcat provides a recommended service schedule for the E20. By adhering to these guidelines, you can prevent premature failure of critical components like the two-speed solenoid.
     

Conclusion
The Bobcat E20 is a powerful and efficient machine, but like all heavy equipment, it requires proper maintenance and attention to keep it running smoothly. The two-speed solenoid is a key component of its transmission system, and when it fails, it can cause significant disruptions in performance. By understanding how the solenoid works, troubleshooting potential issues, and conducting regular maintenance, operators can ensure the continued reliability and efficiency of the Bobcat E20.