Removing the Swing Cylinder on a Takeuchi TB145 Compact Excavator

[MikePhua]

The TB145 and Its Swing Mechanism Design
The Takeuchi TB145 is a compact hydraulic excavator introduced in the early 2000s, designed for precision digging, trenching, and utility work in confined spaces. With an operating weight of approximately 4,800 kg and a dig depth of over 3.5 meters, the TB145 balances power and maneuverability. One of its key features is the boom swing function, allowing lateral movement of the boom for offset digging—especially useful near walls, foundations, or in narrow trenches.
This swing motion is powered by a dedicated hydraulic cylinder mounted between the upper frame and the boom base. Over time, the swing cylinder may develop leaks, lose pressure, or suffer from internal seal failure, requiring removal and rebuild. Unlike main boom or arm cylinders, the swing cylinder is tucked into a tight space, making extraction more challenging.
Terminology Annotation

• Swing Cylinder: A hydraulic actuator that pivots the boom left or right relative to the upper frame.
  
• Boom Base: The fixed portion of the boom where the swing cylinder connects.
  
• Pin Boss: A reinforced housing where a pivot pin is inserted to secure the cylinder.
  
• Hydraulic Line Manifold: A block where multiple hydraulic hoses connect, often near the cylinder ports.
  
• Retaining Clip: A spring-loaded ring that secures the pin in place and prevents axial movement.
  

Preparation and Safety Measures
Before beginning removal:

• Park the machine on level ground and lower all implements.
  
• Shut off the engine and relieve hydraulic pressure by cycling the controls.
  
• Disconnect the battery to prevent accidental startup.
  
• Clean the area around the swing cylinder to prevent contamination.
  

Use proper PPE—gloves, eye protection, and steel-toe boots. The swing cylinder is under tension and may shift when pins are removed.
Accessing the Swing Cylinder
The swing cylinder on the TB145 is located beneath the boom pivot and partially shielded by structural plates. To access:

• Remove the boom side covers or access panels using metric sockets.
  
• Disconnect the hydraulic lines at the cylinder ports—cap both ends to prevent fluid loss.
  
• Identify the mounting pins—typically one at the base and one at the rod end.
  

Inspect the pin bosses for retaining clips or bolts. Some models use internal snap rings, while others rely on external collars.
Pin Removal and Cylinder Extraction
To remove the cylinder:

• Use a punch and hammer to drive out the retaining clips.
  
• Tap the pins gently with a drift punch—avoid bending or scoring.
  
• Support the cylinder with a strap or jack as the second pin is removed.
  
• Slide the cylinder out carefully, watching for interference with hoses or brackets.
  

If the pins are seized:

• Apply penetrating oil and allow time to soak.
  
• Use a hydraulic press or puller if space allows.
  
• Heat the boss gently with a torch to expand the metal—avoid overheating seals.
  

In one documented repair, a technician used a custom-made pin extractor with a threaded rod and plate to pull the base pin without damaging the boss.
Cylinder Inspection and Rebuild
Once removed:

• Inspect the rod for scoring, pitting, or chrome flaking.
  
• Check the gland nut for tightness and seal integrity.
  
• Disassemble the cylinder using a spanner wrench or gland tool.
  
• Replace all seals, wipers, and wear rings with OEM kits.
  

Use hydraulic assembly grease during reinstallation. Torque the gland nut to spec and pressure test the cylinder before reinstalling.
Reinstallation and System Bleeding
To reinstall:

• Align the cylinder with the pin bosses and insert pins with fresh grease.
  
• Reconnect hydraulic lines and torque fittings to spec.
  
• Start the engine and cycle the swing function slowly to purge air.
  
• Check for leaks and verify smooth swing motion.
  

If the boom drifts or hesitates, inspect the control valve and pilot pressure.
Recommendations for Technicians and Operators

• Keep spare swing cylinder seal kits and retaining clips in stock.
  
• Document cylinder removal and rebuild intervals.
  
• Use anti-seize on pin surfaces to ease future removal.
  
• Train operators to avoid abrupt swing stops—this reduces cylinder stress.
  

In high-cycle environments, consider upgrading to cylinders with hardened rods or improved seal profiles.
Closing Reflections
The swing cylinder on the Takeuchi TB145 may be compact, but its role is pivotal. When it fails, the machine loses its lateral reach and trenching finesse. Removing it requires patience, precision, and the right tools—but once rebuilt, it restores the excavator’s full agility. Whether digging beside a foundation or shaping a ditch curve, a healthy swing cylinder keeps the TB145 nimble, responsive, and ready for the next challenge.