Installing Case Drain on a 2006 Caterpillar 246B Skid Steer

[MikePhua]

Introduction
Adding a case drain to a 2006 Caterpillar 246B skid steer loader enhances hydraulic system capability, particularly when adapting to attachments requiring case drain functionality. This modification improves hydraulic fluid return, prevents over-pressurization, and supports better equipment performance and attachment compatibility.
Understanding the Case Drain System

• The case drain returns hydraulic fluid leaking past hydraulic motor and pump seals back to the reservoir, maintaining system pressure balance.
  
• Proper case drain installation prevents fluid backpressure that can cause seal damage and premature component wear.
  
• Attachments with piston pumps or higher flow demand often require dedicated case drain lines.
  

Preparation and Kit Components

• A case drain kit typically includes hydraulic hoses, couplers, mounting brackets, adapters, fittings, clamps, and installation hardware.
  
• OEM kits from Caterpillar ensure compatibility and often come with detailed installation instructions and diagrams.
  
• Before installation, verify kit compatibility with the 2006 246B skid steer model and relevant attachments.
  

Installation Steps

• Secure the machine on a flat, stable surface and ensure hydraulic system is depressurized.
  
• Disconnect the hydraulic motor case drain port on the attachment coupler.
  
• Attach the case drain hose and route it carefully to the hydraulic tank, avoiding sharp bends or pinch points.
  
• Mount supplied brackets to secure hoses and fittings, reducing vibration-induced wear.
  
• Attach the bulkhead fitting to the hydraulic tank or tank return line, ensuring a leak-proof seal.
  
• Connect hoses to the bulkhead fitting and secure clamps.
  
• Refill and bleed the hydraulic system to remove air and verify fluid flow through case drain lines.
  
• Check for leaks and proper routing under operating conditions.
  

Tips and Recommendations

• Drilling the hydraulic tank for the bulkhead fitting requires care to prevent plastic or metal debris contamination; clean thoroughly before reassembly.
  
• Use compatible sealants and grommets rated for hydraulic oil resistance.
  
• Retain original hose routing paths where possible to prevent interference with moving components.
  
• Consult the nearest Caterpillar dealer for technical advice or downloadable installation manuals if needed.
  
• Test attachments after installation under light load conditions before full operation.
  

Terminology

• Case Drain: Hydraulic return line designed to carry small leakage volumes back to the reservoir.
  
• Bulkhead Fitting: Connector installed through the hydraulic tank wall allowing hose connection.
  
• OEM Kit: Original Equipment Manufacturer supply kit ensuring proper fit and function.
  
• Bleeding: Process of removing trapped air from hydraulic circuits.
  
• Piston Pump: Hydraulic pump type with higher internal leakage requiring case drains.
  

Real-World Example
A land clearing contractor operating a 2006 Cat 246B skid steer retrofitted a case drain to accommodate a high-flow brush mulcher attachment. The modification eliminated premature motor seal failures and hydraulic fluid overheating, dramatically increasing attachment uptime and overall machine reliability during intensive operations.
Conclusion
Installing a case drain on the Caterpillar 246B skid steer loader is essential when working with certain high-flow or piston pump attachments. Proper installation using OEM kits and adherence to recommended procedures ensures hydraulic system health, enhances attachment compatibility, and extends equipment service life. Operators should carefully route and secure hoses, maintain clean connections, and verify system integrity post-installation for safe operation.