• When replacing attachments (such as quick-change buckets or hydraulic breakers), the hydraulic quick coupler on their machine did not match the connector on the new attachment.
  
• They were unsure whether their machine used ISO standard couplers, Pioneer couplers, or some special proprietary type.
  
• Concerned about buying the wrong parts, the OP asked knowledgeable users to help identify the coupler and provide purchase advice.
  

• Common Types of Couplers:
  • Most excavators use ISO A or ISO B standard flat face couplers (ISO 16028), especially recent European, American, Japanese, and Korean models.
    
  • Pioneer-style couplers (rounded with ball lock) are common on agricultural tractors but less so on modern excavators.
    
  • Some imported machines (e.g., Komatsu, Hitachi) may use JIC or BSP fittings common in Japan.
    
• How to Identify:
  • Check if the coupler end face is flat (flat face = likely ISO 16028).
    
  • If it has external threads or ball-lock heads, it may be Pioneer or Parker series.
    
  • The safest method is to measure the coupler’s external diameter, male/female thread size with calipers, and then compare sizes at a hydraulic parts store.
    
• Practical Tips:
  • Bring an old coupler removed from your machine to a hydraulic parts store; many stores have sample couplers to compare.
    
  • If the exact type cannot be found, consider replacing the entire set with a standard ISO flat face coupler for easier future maintenance and attachment changes.
    

• For frequent attachment changes, it is recommended to switch to high-quality flat face quick couplers with pressure relief valves—these are safer and easier to operate.
  
• One user shared a cautionary story about having a non-standard quick coupler custom-welded at a local shop, which led to oil leaks and premature coupler damage, causing more trouble than it was worth.
  

Quote:“Excavator hydraulic couplers are best chosen as international standard flat face quick couplers (ISO 16028). They are durable, easy to buy and replace, and make future maintenance hassle-free.
If unsure of the type, physical measurement and bringing the actual coupler to a hydraulic parts store is the most reliable method—don’t just guess by photos or model numbers.”

• First confirm the type (flat face, ball lock, internal/external thread).
  
• Measure dimensions carefully and take clear close-up photos.
  
• Bring the actual coupler to a parts store for comparison.
  
• For peace of mind and compatibility, consider upgrading the whole coupler set to the ISO 16028 flat face standard.