09-29-2025, 01:35 PM
The Bobcat E26 and Its Travel System
The Bobcat E26 is a compact excavator designed for tight spaces and precision work. Introduced as part of Bobcat’s 2–3 ton class lineup, the E26 features a zero tail swing design, making it ideal for urban construction, landscaping, and utility trenching. With an operating weight of around 5,700 lbs and a dig depth of over 8 feet, the E26 balances power and maneuverability.
Its travel system is hydrostatic, meaning each track is powered by a dedicated hydraulic motor. These motors receive fluid from a variable displacement pump, and speed is controlled by proportional valves and joystick input. When one track moves slower than the other, the issue is often hydraulic—not mechanical—and can be traced to a handful of common culprits.
Symptoms of Uneven Track Speed
Operators typically notice:
Common Causes of Track Speed Imbalance
Several factors can cause one track to move slower:
To resolve the issue:
A contractor in British Columbia noticed his E26 drifting left during trenching. After inspecting the undercarriage and finding no mechanical issues, he swapped the travel valves and saw the problem shift sides. Replacing the faulty valve restored balanced travel.
Another operator in Ohio found that his machine’s right track slowed only in reverse. The joystick potentiometer was sending a weak signal in that direction. Replacing the joystick resolved the issue without touching the hydraulics.
Preventive Maintenance Tips
To avoid future imbalance:
When one track on a Bobcat E26 moves slower than the other, the cause is often hydraulic and localized. By following a structured diagnostic path—starting with mechanical inspection and moving through fluid, valves, and electronics—operators can pinpoint the issue and restore full performance. With proper care and attention to detail, the E26 remains a reliable and precise tool for compact excavation tasks.
The Bobcat E26 is a compact excavator designed for tight spaces and precision work. Introduced as part of Bobcat’s 2–3 ton class lineup, the E26 features a zero tail swing design, making it ideal for urban construction, landscaping, and utility trenching. With an operating weight of around 5,700 lbs and a dig depth of over 8 feet, the E26 balances power and maneuverability.
Its travel system is hydrostatic, meaning each track is powered by a dedicated hydraulic motor. These motors receive fluid from a variable displacement pump, and speed is controlled by proportional valves and joystick input. When one track moves slower than the other, the issue is often hydraulic—not mechanical—and can be traced to a handful of common culprits.
Symptoms of Uneven Track Speed
Operators typically notice:
- One track moves slower in forward or reverse
- The machine veers off course during straight travel
- Turning is inconsistent or jerky
- No visible leaks or warning codes
- Other hydraulic functions (boom, bucket) work normally
Common Causes of Track Speed Imbalance
Several factors can cause one track to move slower:
- Sticking Proportional Valve
The valve controlling flow to the affected motor may be sticking or partially blocked. This reduces flow and pressure, limiting speed.
- Contaminated Hydraulic Fluid
Debris or water in the fluid can clog screens or damage valve seats. Even small particles can disrupt flow in precision components.
- Weak Travel Motor
The hydraulic motor itself may be worn or internally leaking. This reduces torque and speed under load.
- Joystick Signal Deviation
The electronic signal from the joystick may be uneven, causing one valve to open less than the other. This can result from a faulty potentiometer or wiring issue.
- Relief Valve Malfunction
If the relief valve on one side is opening prematurely, it will bleed off pressure and slow the motor.
- Track Tension or Mechanical Drag
Uneven track tension, seized rollers, or debris in the undercarriage can create resistance. While less common, this mechanical drag can mimic hydraulic imbalance.
To resolve the issue:
- Check Track Tension and Undercarriage
Measure track sag and inspect rollers. Remove debris and verify both tracks rotate freely when lifted off the ground.
- Inspect Hydraulic Fluid and Filters
Look for contamination, discoloration, or water. Replace filters and flush the system if needed.
- Test Joystick Output
Use a diagnostic tool to compare voltage or signal strength between left and right travel commands.
- Swap Proportional Valves
If the issue follows the valve, it’s likely sticking or damaged. Clean or replace as needed.
- Measure Motor Case Drain Flow
Excessive flow from the motor’s case drain line indicates internal leakage. Replace or rebuild the motor.
- Check Relief Valve Settings
Use a pressure gauge to verify relief valve activation points. Adjust or replace if one side is opening too early.
A contractor in British Columbia noticed his E26 drifting left during trenching. After inspecting the undercarriage and finding no mechanical issues, he swapped the travel valves and saw the problem shift sides. Replacing the faulty valve restored balanced travel.
Another operator in Ohio found that his machine’s right track slowed only in reverse. The joystick potentiometer was sending a weak signal in that direction. Replacing the joystick resolved the issue without touching the hydraulics.
Preventive Maintenance Tips
To avoid future imbalance:
- Replace hydraulic filters every 500 hours
- Use OEM-spec fluid and avoid mixing brands
- Clean joystick and control panel connectors quarterly
- Grease track rollers and inspect for wear
- Monitor travel motor temperature during operation
When one track on a Bobcat E26 moves slower than the other, the cause is often hydraulic and localized. By following a structured diagnostic path—starting with mechanical inspection and moving through fluid, valves, and electronics—operators can pinpoint the issue and restore full performance. With proper care and attention to detail, the E26 remains a reliable and precise tool for compact excavation tasks.
