Case 1840 Hydraulic Hose Issue

[MikePhua]

Case 1840 Overview
The Case 1840 is a skid steer loader manufactured between 1989 and 2001 by Case Construction Equipment, a division of CNH Industrial. It features a Tier 1 diesel engine producing roughly 60–70 hp, a rated operating capacity of 1,800 lbs, and a robust hydraulic system designed to power attachments and loader arms efficiently. Case, founded in 1842, has a long history in agricultural and construction machinery, and the 1840 was popular due to its reliability, compact size, and versatility for both construction and landscaping tasks.
Problem Description
Operators upgrading or repairing the auxiliary high-flow system often encounter confusion regarding hose connections to a valve assembly. Common issues include:

• Mixed-up supply and return hoses, which can lead to improper hydraulic flow
  
• Solenoid-operated valves, such as self-leveling or float valves, complicating identification
  
• Difficulty accessing hoses due to tight clearances on the machine
  
• Risk of pump damage if hoses are connected incorrectly and the system is pressurized
  

The auxiliary high-flow system is often retrofitted after the loader is built, which can add to the complexity of installation and maintenance. Some operators may not use the high-flow system regularly, leaving hoses disconnected or capped.
Technical Terminology Explained

• Supply line: The hose carrying pressurized hydraulic fluid from the pump to the valve or attachment
  
• Return line: The hose carrying fluid back to the reservoir after passing through the valve or implement
  
• Solenoid valve: An electrically operated valve controlling hydraulic flow or pressure
  
• Dead heading: Operating a pump against a closed line, which can cause overpressure and catastrophic failure
  

Diagnosis and Safety Recommendations
If hoses are suspected to be reversed, operators should take precautionary steps:

• Avoid starting the machine until the hydraulic schematic is verified
  
• Identify valve ports, often marked “P” for pressure and “R” for return, or consult the dealer for the correct diagram
  
• Cap both hoses temporarily if the high-flow system is not in use to prevent accidental pump overpressure
  
• Inspect hose lengths and routing to ensure no kinking or tension that could interfere with function
  
• Replace hoses individually, ensuring each end is connected properly to avoid confusion
  

Consulting a Case dealer for the official hydraulic schematic is highly recommended to prevent damage. Starting the system with incorrect hose connections can lead to immediate pump failure and severe repair costs.
Field Experience
One operator described spending four days fabricating a replacement hose for the auxiliary system. Despite replacing each hose one at a time to ensure proper connection at the valve, uncertainty remained about which end connected to the loader. This illustrates the challenges faced when working with retrofitted hydraulic systems on older skid steers and the importance of careful labeling and schematic verification.
Maintenance and Operational Advice

• Mark all hoses clearly during maintenance or replacement to avoid confusion
  
• Check that solenoid valves function correctly and have not been damaged by reversed flow
  
• Cap or disconnect unused high-flow lines safely to protect the pump
  
• Regularly inspect hoses and fittings for wear, leaks, and proper routing
  
• Maintain a clear maintenance log for future troubleshooting
  

Conclusion
The Case 1840 skid steer loader remains a versatile and reliable machine, but retrofitted high-flow hydraulic systems can introduce complexity. Proper identification of supply and return lines, careful hose management, and consulting official schematics are essential to prevent damage. Operators should prioritize safety, avoid dead-heading the pump, and maintain rigorous maintenance practices to ensure continued performance and reliability.