Case 1845C Hydraulic System

[MikePhua]

The Case 1845C is one of the most iconic skid steer loaders in construction history. Produced from 1985 until 2000, it carried a reputation for rugged simplicity and reliability. Over its 15-year production run, thousands of units were sold worldwide, making it one of Case’s best-selling machines. Its hydrostatic drive and powerful auxiliary hydraulics were a leap forward compared with earlier models, enabling operators to run demanding attachments like trenchers, augers, and hydraulic hammers. Understanding and maintaining the hydraulic system is crucial to preserving its performance and extending machine life.

Hydraulic Fluid Types
The 1845C typically uses a premium hydraulic/transmission fluid meeting Case MS-1207 or MS-1209 specifications. These fluids are specially formulated to provide correct viscosity across a wide temperature range, prevent foaming, and protect against wear in hydraulic pumps, motors, and control valves. Using standard automatic transmission fluid (ATF) or engine oil is not recommended, as their friction modifiers and detergents can interfere with wet-brake and hydrostatic components.

Capacity and Maintenance
The hydraulic reservoir of the 1845C holds approximately 11 to 12 gallons of fluid, depending on whether auxiliary lines are installed. Operators are advised to:

• Check fluid daily before operation
  
• Maintain oil level between the sight glass marks
  
• Replace fluid every 1,000 operating hours or annually for heavy-duty usage
  
• Replace filters at least every 500 hours or sooner if contamination is suspected
  

Neglecting maintenance can lead to pump cavitation, slow bucket response, or overheating.

Symptoms of Fluid Issues
Operators can spot hydraulic problems early by watching for key symptoms:

• Whining noise from pumps – often a sign of low fluid or air in the system
  
• Slow hydraulic cycle times – may indicate worn oil or plugged filters
  
• Overheating hydraulic tank – typically points to improper fluid type or low oil level
  
• Foamy or milky oil – suggests water contamination, which reduces lubrication
  

Regular oil analysis can help catch early signs of wear metals, dirt, or coolant intrusion, avoiding costly repairs.

Seasonal Considerations
Cold weather operation demands hydraulic fluids with excellent low-temperature flow properties. Multi-viscosity universal tractor hydraulic oils (UTTO) designed for –20 °F or colder help reduce pump strain at startup. Some operators install hydraulic tank heaters in severe climates to avoid cavitation and sluggish controls.

Real-World Anecdote
In Minnesota, a contractor operating a Case 1845C for snow removal noticed that after a cold snap, the loader arms were extremely slow to lift. After switching to a premium synthetic hydraulic oil rated for extreme cold and flushing the system, cycle times improved by nearly 40%. This case demonstrates how fluid choice alone can dramatically impact machine productivity.

Best Practices for Longevity
To maximize the life of the hydraulic system:

• Always clean the filler cap and surrounding area before adding oil
  
• Use dedicated, clean funnels to avoid introducing grit into the system
  
• Monitor hoses for leaks and cracks since dirt entry can contaminate fluid
  
• Keep breather caps and filters replaced to maintain proper system ventilation
  
• Avoid running the tank too low, as air ingestion is a common cause of pump failure
  

Manufacturer and Legacy
Case Construction Equipment, part of CNH Industrial, has produced loaders since the 1960s. The 1845C became a benchmark for durability—many units are still in service today with over 10,000 hours logged. Its strong resale value reflects the respect it earned from contractors and farmers alike. The machine’s hydraulic design became a model for later Case skid steers, showing that proper fluid maintenance was a cornerstone of its longevity.

Terminology Notes

• Hydrostatic drive – a drive system using hydraulic pumps and motors to transmit power smoothly
  
• Cavitation – the formation of vapor bubbles inside a pump that collapse and cause damage
  
• Viscosity index – a measure of how much oil thickens or thins with temperature change
  
• Wet-brake system – a braking system where components are immersed in hydraulic oil for cooling and lubrication
  

Conclusion
Maintaining the correct hydraulic fluid in a Case 1845C is more than a technical recommendation—it is the key to preserving performance, preventing expensive downtime, and ensuring the loader continues to operate like it did when it rolled off the factory floor. By choosing the right oil, adhering to maintenance schedules, and paying attention to seasonal conditions, operators can keep these legendary machines working reliably for decades to come.