10-23-2025, 11:43 AM
Overview of the Bobcat E63
The Bobcat E63 is a 6-ton class compact excavator introduced in the early 2010s as part of Bobcat’s mid-size lineup. Designed for urban excavation, utility trenching, and grading, the E63 features a turbocharged diesel engine producing approximately 59.4 horsepower, a closed-center hydraulic system, and a conventional tail swing. With an operating weight of around 13,779 lbs and a maximum digging depth of 13.5 feet, the E63 balances power and maneuverability. Bobcat, founded in 1947, has sold tens of thousands of compact excavators globally, with the E63 gaining popularity for its smooth controls and robust build.
Symptoms of Hydraulic Noise and Stick Pulsation
A common issue reported on the E63 involves a high-pitched hydraulic whine that emerges once the machine warms up. The noise intensifies when multiple functions are actuated simultaneously or when any single function is fully engaged. Additionally, the stick function may exhibit pulsation—a rhythmic hesitation or surging—especially when pulling in while grading.
Despite these symptoms, there is no reported loss of power or function. Hydraulic fluid levels are within range, the oil appears clean, and the machine was serviced prior to operation. Belts have been inspected and tightened, and accessory systems have been ruled out.
Possible Causes and Diagnostic Path
These symptoms suggest a pressure-related anomaly within the hydraulic system. Potential causes include:
Field Experience and Anecdotes
In 2022, a contractor in Minnesota reported similar symptoms on a Bobcat E63 with 1,300 hours. After replacing the suction filter and inspecting the tank pressurization valve, the whine disappeared and stick movement stabilized. The root cause was traced to a cracked suction hose near the pump inlet, which allowed air ingress under load.
Another operator in the UK found that a worn pilot control valve caused pulsation in the stick circuit. Replacing the valve resolved the issue, though the hydraulic whine persisted until the relief valve was recalibrated.
Recommended Troubleshooting Steps
Conclusion
Hydraulic whine and stick pulsation in the Bobcat E63 are often linked to suction-side restrictions, tank pressure anomalies, or relief valve behavior. While the machine may continue to operate without loss of function, addressing these issues improves efficiency, reduces wear, and enhances operator comfort. With methodical inspection and targeted maintenance, the E63 can continue delivering reliable performance across demanding job sites.
The Bobcat E63 is a 6-ton class compact excavator introduced in the early 2010s as part of Bobcat’s mid-size lineup. Designed for urban excavation, utility trenching, and grading, the E63 features a turbocharged diesel engine producing approximately 59.4 horsepower, a closed-center hydraulic system, and a conventional tail swing. With an operating weight of around 13,779 lbs and a maximum digging depth of 13.5 feet, the E63 balances power and maneuverability. Bobcat, founded in 1947, has sold tens of thousands of compact excavators globally, with the E63 gaining popularity for its smooth controls and robust build.
Symptoms of Hydraulic Noise and Stick Pulsation
A common issue reported on the E63 involves a high-pitched hydraulic whine that emerges once the machine warms up. The noise intensifies when multiple functions are actuated simultaneously or when any single function is fully engaged. Additionally, the stick function may exhibit pulsation—a rhythmic hesitation or surging—especially when pulling in while grading.
Despite these symptoms, there is no reported loss of power or function. Hydraulic fluid levels are within range, the oil appears clean, and the machine was serviced prior to operation. Belts have been inspected and tightened, and accessory systems have been ruled out.
Possible Causes and Diagnostic Path
These symptoms suggest a pressure-related anomaly within the hydraulic system. Potential causes include:
- Relief valve chatter: When system pressure approaches the relief threshold, valves may oscillate, producing a whine. This is common in closed-center systems under high demand.
- Aeration or cavitation: Air bubbles in the fluid can cause noise and erratic movement. This may result from a loose suction line, clogged suction filter, or low tank pressure.
- Suction line restriction: A partially blocked suction line or dirty filter can starve the pump, leading to noise and pulsation.
- Hydraulic tank pressure loss: The E63 uses a pressurized hydraulic tank to assist fluid delivery. If tank pressure drops, flow may become unstable.
Field Experience and Anecdotes
In 2022, a contractor in Minnesota reported similar symptoms on a Bobcat E63 with 1,300 hours. After replacing the suction filter and inspecting the tank pressurization valve, the whine disappeared and stick movement stabilized. The root cause was traced to a cracked suction hose near the pump inlet, which allowed air ingress under load.
Another operator in the UK found that a worn pilot control valve caused pulsation in the stick circuit. Replacing the valve resolved the issue, though the hydraulic whine persisted until the relief valve was recalibrated.
Recommended Troubleshooting Steps
- Inspect suction lines and clamps for cracks or looseness
- Replace suction filter if last service date is unknown
- Test hydraulic tank pressure using the vent button or a gauge
- Check relief valve settings and recalibrate if necessary
- Monitor pilot control response for signs of internal wear
Conclusion
Hydraulic whine and stick pulsation in the Bobcat E63 are often linked to suction-side restrictions, tank pressure anomalies, or relief valve behavior. While the machine may continue to operate without loss of function, addressing these issues improves efficiency, reduces wear, and enhances operator comfort. With methodical inspection and targeted maintenance, the E63 can continue delivering reliable performance across demanding job sites.
