Kobelco SK135SR Control Pattern Change

[MikePhua]

Background on the Kobelco SK135SR
The Kobelco SK135SR is a compact-to-mid excavator widely used in construction, landscaping, and urban work sites. Its hydraulic system uses two variable‑displacement pumps and a pilot‑operated control scheme, typical for its class.  Kobelco offers a “control pattern changer” as an optional feature on this model, meaning the joystick/directional control layout can be swapped.
Why Change the Control Pattern
Operators often prefer different control layouts depending on their background. Two common patterns are:

• ISO / “Cat” style: Right lever = boom + bucket, left lever = swing + stick.
  
• SAE / “Deere / JD” style: Right lever = stick + bucket, left lever = boom + swing.
  

One user reported their machine had been rewired to use Deere-style controls and needed help returning it back to “Cat style” (ISO).
How to Make the Change
Based on shared user experience:

1. Locate the pattern‑change switch: The SK135SR‑2 model supports a 4‑way pattern changer per the parts/option list.
   
2. Swap lines: According to a detailed post, to go from Deere to Cat style: rearrange hydraulic pilot lines—specifically:
   • Swap line 1 and line 4
     
   • Swap line 2 and line 3
     
   • In that user’s machine, line 1 was tan, line 2 was green, line 3 was green, and line 4 was blue.
     
3. Confirm the pattern: After the line swap, test the joysticks to make sure the functions now match Cat / ISO layout.
   

Things to Be Careful With

• Be sure to label or document old line routing before changing anything, in case you need to revert.
  
• Work with clean hydraulic fluid: when disconnecting pilot lines, you risk introducing air or contamination.
  
• After rewiring, bleed the pilot circuit to remove trapped air.
  
• Confirm that any software or display-based “mode” (if present) also matches the new physical control layout.
  

Why Some Dealers Don’t Help Much
A few operators report that their local Kobelco dealers were not very helpful with pattern-change guidance. This is likely because:

• The change is often considered a “user‑modification” rather than a factory default.
  
• Dealers may not regularly perform pattern swaps and therefore lack hands‑on experience.
  So, using community resources (like wiring diagrams shared by other users) can be very valuable.
  

Summary

• The SK135SR supports a manual control‑pattern swap using a 4‑way pattern changer.
  
• By swapping specific pilot lines (1↔4, 2↔3), you can convert between Deere-style and Cat-style control.
  
• After the change, testing and bleeding are essential to ensure smooth and correct operation.