09-29-2025, 04:12 PM
The TX5519 and Its Role in Compact Material Handling
The Terex TX5519 telehandler was designed for tight-space lifting and material placement, offering a maximum lift height of 19 feet and a rated capacity of 5,500 lbs. Introduced in the early 2000s, it targeted contractors, rental fleets, and industrial users needing maneuverability without sacrificing reach. Its compact frame, four-wheel drive, and side-mounted boom made it ideal for navigating congested job sites.
The TX5519 uses a load-sensing hydraulic system with proportional control valves to manage boom lift, extension, and auxiliary functions. These systems rely on precise electrical signals and fluid flow regulation to deliver smooth, responsive movement. When the hydraulics begin to slow down, especially during boom operation, the issue is often electrical or valve-related—not necessarily pump or filter failure.
Symptoms of Hydraulic Slowness
Operators may notice:
Proportional Coil and Cartridge Valve Diagnostics
The proportional coil is an electrically actuated solenoid that modulates hydraulic flow based on joystick input. It controls the movement of a cartridge valve inside the manifold block. If the coil fails or the cartridge sticks, flow to the boom cylinder may be reduced or blocked.
Diagnostic steps include:
Locating the Coil and Cartridge Assembly
On the TX5519, the proportional coil is typically mounted on the hydraulic control block near the boom base. It may be labeled with a part number or color-coded for function. The cartridge valve sits inside the block and is retained by a threaded cap.
To access:
Additional Causes of Hydraulic Delay
If the coil and cartridge are functioning, other potential causes include:
Preventive Maintenance and Long-Term Solutions
To prevent hydraulic slowness:
Conclusion
Hydraulic slowness in the Terex TX5519 telehandler is often caused by electrical or mechanical faults in the proportional coil and cartridge valve assembly. With proper diagnostics, cleaning, and preventive care, operators can restore full boom speed and maintain reliable lifting performance. In compact telehandlers, precision flow control is everything—and even a small coil can make a big difference.
The Terex TX5519 telehandler was designed for tight-space lifting and material placement, offering a maximum lift height of 19 feet and a rated capacity of 5,500 lbs. Introduced in the early 2000s, it targeted contractors, rental fleets, and industrial users needing maneuverability without sacrificing reach. Its compact frame, four-wheel drive, and side-mounted boom made it ideal for navigating congested job sites.
The TX5519 uses a load-sensing hydraulic system with proportional control valves to manage boom lift, extension, and auxiliary functions. These systems rely on precise electrical signals and fluid flow regulation to deliver smooth, responsive movement. When the hydraulics begin to slow down, especially during boom operation, the issue is often electrical or valve-related—not necessarily pump or filter failure.
Symptoms of Hydraulic Slowness
Operators may notice:
- Boom raises sluggishly even at high engine RPM
- Hydraulic functions respond slowly or intermittently
- No warning lights or fault codes on the dash
- Filters and pump appear to be functioning normally
- Engine sounds normal but hydraulic effort is weak
Proportional Coil and Cartridge Valve Diagnostics
The proportional coil is an electrically actuated solenoid that modulates hydraulic flow based on joystick input. It controls the movement of a cartridge valve inside the manifold block. If the coil fails or the cartridge sticks, flow to the boom cylinder may be reduced or blocked.
Diagnostic steps include:
- Measure resistance across the coil terminals (typical range: 8–12 ohms)
- Check voltage supply and ground continuity during operation
- Inspect connectors for corrosion or loose pins
- Remove the cartridge and check for smooth movement and debris
- Clean or replace the cartridge if binding is detected
Locating the Coil and Cartridge Assembly
On the TX5519, the proportional coil is typically mounted on the hydraulic control block near the boom base. It may be labeled with a part number or color-coded for function. The cartridge valve sits inside the block and is retained by a threaded cap.
To access:
- Shut down the machine and relieve hydraulic pressure
- Disconnect the coil wiring harness
- Unscrew the coil retaining nut and slide the coil off
- Use a hex wrench to remove the cartridge
- Inspect for scoring, contamination, or spring failure
Additional Causes of Hydraulic Delay
If the coil and cartridge are functioning, other potential causes include:
- Low voltage from joystick controller
- Weak hydraulic charge pressure
- Internal leakage in boom lift cylinder
- Contaminated fluid causing valve stiction
- Software calibration drift in electronic control module
- Test joystick output voltage during actuation
- Monitor system pressure with gauges at multiple ports
- Inspect cylinder seals for bypass
- Flush fluid and replace with ISO 46 hydraulic oil
- Recalibrate control module if applicable
Preventive Maintenance and Long-Term Solutions
To prevent hydraulic slowness:
- Replace hydraulic filters every 500 hours
- Inspect coil connectors monthly
- Clean cartridge valves annually
- Use dielectric grease on electrical terminals
- Avoid operating in extreme cold without warm-up cycles
- Train operators to avoid abrupt joystick movements
Conclusion
Hydraulic slowness in the Terex TX5519 telehandler is often caused by electrical or mechanical faults in the proportional coil and cartridge valve assembly. With proper diagnostics, cleaning, and preventive care, operators can restore full boom speed and maintain reliable lifting performance. In compact telehandlers, precision flow control is everything—and even a small coil can make a big difference.
