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The Case 170B and Its Mechanical Simplicity
The Case 170B excavator was part of Case’s early hydraulic excavator lineup, built during a time when mechanical reliability and straightforward hydraulics were prioritized over electronic complexity. With an operating weight in the 17–18 ton range and powered by a turbocharged diesel engine, the 170B was designed for general excavation, trenching, and site prep. Its control system is fully hydraulic, with pilot-operated joysticks and valve banks rather than electronic actuators.
Unlike modern excavators that offer pattern change via a selector switch or software toggle, older machines like the 170B require manual reconfiguration of hydraulic lines to change the control pattern.
Terminology Clarification
Before changing the control pattern, it’s critical to immobilize the boom and stick to prevent unintended movement when hydraulic lines are disconnected. This can be done by:
Swapping Hydraulic Lines to Change Pattern
The control pattern is determined by how the pilot hoses are routed to the valve bank. To switch from one pattern to another:
Once the hoses are in place:
Operators who’ve worked on older machines often develop their own methods. In Tacoma, one operator converted his Deere backhoe to CAT pattern by rerouting hoses at a single control box. He emphasized the importance of blocking the boom and stick, noting that oil discharge during hose removal can cause sudden movement if not secured.
In rural Virginia, a farmer traced his pilot hoses manually due to lack of documentation. He used colored zip ties to mark each line and took photos before disassembly—a simple but effective strategy.
Recommendations for Safe and Effective Conversion
Changing the control pattern on a Case 170B excavator is a hands-on process that requires mechanical awareness and attention to hydraulic safety. While newer machines offer electronic toggles, older models demand manual hose swaps and careful testing. With proper preparation and methodical execution, operators can customize their control layout to match personal preference or crew standard—bringing modern flexibility to a classic machine.
The Case 170B excavator was part of Case’s early hydraulic excavator lineup, built during a time when mechanical reliability and straightforward hydraulics were prioritized over electronic complexity. With an operating weight in the 17–18 ton range and powered by a turbocharged diesel engine, the 170B was designed for general excavation, trenching, and site prep. Its control system is fully hydraulic, with pilot-operated joysticks and valve banks rather than electronic actuators.
Unlike modern excavators that offer pattern change via a selector switch or software toggle, older machines like the 170B require manual reconfiguration of hydraulic lines to change the control pattern.
Terminology Clarification
- Control Pattern: The layout of joystick movements that control boom, stick, bucket, and swing functions. Common patterns include SAE (backhoe) and ISO (excavator).
- Pilot Controls: Low-pressure hydraulic signals from the joysticks that actuate the main control valves.
- Valve Bank: A series of hydraulic valves that direct fluid to the cylinders based on pilot input.
- Stick and Boom: The two main arms of the excavator; the boom lifts vertically, while the stick extends outward.
Before changing the control pattern, it’s critical to immobilize the boom and stick to prevent unintended movement when hydraulic lines are disconnected. This can be done by:
- Lowering the boom fully and raising the stick slightly
- Placing cribbing blocks under both arms to support their weight
- Relieving hydraulic pressure by cycling the controls with the engine off
- Boom Up
- Boom Down
- Stick In
- Stick Out
Swapping Hydraulic Lines to Change Pattern
The control pattern is determined by how the pilot hoses are routed to the valve bank. To switch from one pattern to another:
- Disconnect the pilot hoses for Boom Up and Stick Out
- Swap their positions and reconnect
- Repeat for Boom Down and Stick In
Once the hoses are in place:
- Start the machine and test each function slowly
- Confirm that joystick movements match the desired pattern
- If correct, perform final tightening of all fittings
- Replace any hose clamps or routing brackets that were removed
Operators who’ve worked on older machines often develop their own methods. In Tacoma, one operator converted his Deere backhoe to CAT pattern by rerouting hoses at a single control box. He emphasized the importance of blocking the boom and stick, noting that oil discharge during hose removal can cause sudden movement if not secured.
In rural Virginia, a farmer traced his pilot hoses manually due to lack of documentation. He used colored zip ties to mark each line and took photos before disassembly—a simple but effective strategy.
Recommendations for Safe and Effective Conversion
- Always depressurize the system before disconnecting any hydraulic lines
- Use clean rags and caps to prevent contamination during hose swaps
- Keep a diagram or photo record of original hose routing
- Test slowly and be prepared to shut down immediately if movement is erratic
- Consider installing quick-connect fittings if frequent pattern changes are needed
Changing the control pattern on a Case 170B excavator is a hands-on process that requires mechanical awareness and attention to hydraulic safety. While newer machines offer electronic toggles, older models demand manual hose swaps and careful testing. With proper preparation and methodical execution, operators can customize their control layout to match personal preference or crew standard—bringing modern flexibility to a classic machine.
