Resealing the Bobcat HB880 Hydraulic Breaker: A Practical Guide to Diagnosis and Repair

[MikePhua]

Understanding the HB880 Hydraulic Breaker
The Bobcat HB880 is a mid-range hydraulic breaker attachment designed for skid steers and compact excavators. It’s commonly used in demolition, trenching, and rock breaking applications. Like most hydraulic hammers, it relies on high-pressure oil to drive a piston that delivers impact energy to a chisel or moil point. Over time, seals degrade due to heat, pressure, and contamination, leading to oil leaks and reduced performance.
Terminology Clarification

• Hydraulic Breaker: A percussion tool powered by hydraulic fluid, used to break concrete, rock, or asphalt.
  
• Seal Kit: A collection of O-rings, bushings, and gaskets used to restore hydraulic integrity.
  
• Accumulator: A pressurized chamber that stores hydraulic energy and dampens shock loads.
  
• Piston: The internal component that moves under hydraulic pressure to strike the tool bit.
  
• Tool Retainer: A mechanism that holds the chisel or moil point in place during operation.
  

Initial Diagnosis: Oil Leak and Performance Check
The HB880 in question was mounted on a Bobcat S300 skid steer and showed signs of oil leakage despite functioning normally. This is a common symptom of worn seals, particularly around the piston housing or accumulator. While the hammer still delivered adequate force, the leak posed environmental risks and could lead to internal damage if left unaddressed.
Operators should look for:

• Oil pooling near the tool retainer or body seam
  
• Reduced impact force or erratic operation
  
• Unusual noises during cycling
  
• Visible wear on external bushings or hoses
  

Cost Estimation and Parts Availability
One technician referenced resealing a similar NPK PH3 hammer, with parts costing approximately $500. While the HB880 may differ slightly in design, this figure provides a reasonable benchmark. Seal kits for the HB880 are available through Bobcat dealers and aftermarket suppliers, though prices vary based on region and kit completeness.
Disassembly and Resealing Procedure
Resealing a hydraulic breaker requires mechanical precision and safety awareness. The process typically involves:

• Removing the Tool Bit
  Use a punch and hammer to drive out the retainer pins and extract the chisel.
  
• Draining Hydraulic Fluid
  Disconnect hoses and allow residual oil to drain into a clean container.
  
• Disassembling the Housing
  Unbolt the upper and lower body sections, exposing the piston and internal seals.
  
• Inspecting Components
  Check the piston, bushings, and wear plates for scoring or deformation.
  
• Replacing Seals
  Carefully remove old seals using plastic picks. Install new seals with lubrication to prevent tearing.
  
• Reassembling and Testing
  Torque bolts to spec, reconnect hoses, and cycle the hammer at low pressure to check for leaks.
  

Field Anecdote: The Florida Hammer Hustle
In Kissimmee, Florida, a contractor used an HB880 to break up a concrete pool deck. Midway through the job, oil began seeping from the lower housing. Rather than halting work, the operator wrapped the leak with absorbent pads and finished the demolition. Later, a local hydraulic shop resealed the unit for under $600, including labor. The technician noted that the piston seals had hardened and cracked—classic signs of heat degradation.
Preventive Maintenance Tips

• Replace seals every 1,000–1,500 operating hours
  
• Use high-quality hydraulic oil with anti-foaming additives
  
• Avoid dry firing (operating without tool contact)
  
• Store the breaker vertically to prevent seal distortion
  
• Inspect tool retainers and bushings monthly
  

Industry Insight: The Rise of Compact Breakers
Hydraulic breakers like the HB880 have become indispensable in urban demolition, where noise and vibration restrictions limit traditional methods. In 2022, a construction firm in Tokyo used compact breakers to dismantle a multi-story parking garage without disturbing nearby businesses. The HB880’s low recoil and precise control made it ideal for tight spaces and delicate concrete removal.
Conclusion
Resealing a Bobcat HB880 hydraulic breaker is a manageable task for experienced technicians and a worthwhile investment for operators. With proper diagnosis, quality parts, and attention to detail, the hammer can return to peak performance and extend its service life. Whether breaking concrete in Florida or trenching in Tokyo, the HB880 proves that even compact tools can deliver heavyweight results.