Troubleshooting Tandem Pump Issues on a Case 1845C Skid Steer

[MikePhua]

Introduction
The Case 1845C skid steer loader is a highly versatile and reliable machine, commonly used for digging, lifting, and material handling tasks. However, like any complex machinery, issues can arise, and one common problem is related to the tandem pump system. The tandem pump is crucial for providing hydraulic power to the machine’s lift arms, wheels, and attachments. When this system begins to malfunction, it can affect the machine's performance. This article covers the common tandem pump issues on the Case 1845C and provides troubleshooting steps to diagnose and fix the problem.
Understanding the Tandem Pump System

1. What is a Tandem Pump?
   The tandem pump in the Case 1845C is a dual-stage hydraulic pump designed to supply hydraulic fluid to multiple systems. It ensures that the loader's lifting arms, drive system, and attachments operate smoothly. The tandem pump consists of two separate pumps mounted on the same shaft, providing both high-flow and low-flow hydraulic power to various parts of the machine.
   
2. Symptoms of a Faulty Tandem Pump
   When the tandem pump begins to fail, several symptoms can emerge:
   • Slow or Weak Performance: The machine might experience slow or weak lifting functions, making it hard to perform basic tasks like raising the loader arms or moving attachments.
     
   • Uneven Power Distribution: If one side of the loader is weaker than the other or if there is a noticeable lag in certain hydraulic functions, it may indicate an issue with the pump.
     
   • Noise or Vibration: Abnormal sounds such as whining, grinding, or excessive vibration can be signs that the pump is malfunctioning, possibly due to wear or internal damage.
     

Common Causes of Tandem Pump Issues

1. Low Hydraulic Fluid
   One of the most common causes of tandem pump issues is low hydraulic fluid levels. Insufficient fluid can cause the pump to work harder, leading to overheating or insufficient pressure in the hydraulic system.
   Solution: Check the hydraulic fluid level regularly and top it up with the correct type of fluid. Ensure there are no leaks in the system that could lead to fluid loss.
   
2. Contaminated Hydraulic Fluid
   Hydraulic fluid contamination, often caused by dirt, debris, or moisture entering the system, can damage the tandem pump. Contaminants can clog filters, obstruct hydraulic lines, and reduce the pump’s efficiency.
   Solution: Drain the old hydraulic fluid and replace it with fresh fluid. Replace the hydraulic filters and clean the system to ensure that contaminants are removed.
   
3. Worn or Damaged Pump Components
   Over time, the internal components of the tandem pump can wear out or become damaged. This can be due to poor maintenance, lack of lubrication, or simply the wear and tear from prolonged use.
   Solution: Inspect the tandem pump for any visible signs of damage, such as cracks or worn seals. If necessary, disassemble the pump to check the internal components, including the gears, pistons, and seals, and replace any worn-out parts.
   
4. Incorrect Pump Pressure
   The tandem pump operates under a specific pressure range. If the pump’s pressure is too low, it won’t provide sufficient power to the loader’s hydraulic system. Conversely, if the pressure is too high, it can lead to overheating and premature failure of the pump or other hydraulic components.
   Solution: Use a pressure gauge to measure the hydraulic system's pressure. If the pressure is outside the recommended range, adjust it according to the manufacturer’s specifications.
   
5. Air in the Hydraulic System
   Air trapped in the hydraulic lines can cause the pump to operate inefficiently, leading to inconsistent performance. Air can enter the system through loose connections, leaks, or improperly bled lines.
   Solution: Bleed the hydraulic system to remove any trapped air. Ensure all hydraulic connections are tight and free from leaks.
   

Troubleshooting Steps for Tandem Pump Issues

1. Step 1: Inspect Hydraulic Fluid Levels
   The first step is to check the hydraulic fluid levels. Low fluid can cause a variety of issues, including poor pump performance and overheating. If the fluid is low, top it up and monitor the performance to see if the issue resolves.
   
2. Step 2: Check for Leaks
   Inspect the hydraulic lines, hoses, and connections for any signs of leaks. Leaks can lead to fluid loss and poor performance. If any leaks are found, replace the damaged parts and tighten any loose connections.
   
3. Step 3: Test Hydraulic Pressure
   Use a hydraulic pressure gauge to measure the pressure in the system. Compare the reading to the manufacturer’s specifications. If the pressure is too low or too high, adjust the pump or replace any components causing the pressure issue.
   
4. Step 4: Inspect and Replace Filters
   Dirty or clogged filters can cause poor hydraulic flow and pump performance. Replace the hydraulic filters regularly, and clean the filter housing to ensure optimal flow.
   
5. Step 5: Inspect the Pump for Damage
   If the fluid levels, pressure, and filters are all in good condition, the issue may lie with the pump itself. Inspect the tandem pump for any visible damage, such as cracked housing or worn-out seals. If internal damage is suspected, consider having the pump professionally serviced or replaced.
   
6. Step 6: Bleed the Hydraulic System
   If air is suspected in the system, bleed the hydraulic lines to remove trapped air. Air in the system can cause inconsistent performance and reduce the overall efficiency of the tandem pump.
   

Preventive Maintenance Tips

1. Regular Fluid Checks: Ensure that the hydraulic fluid levels are maintained at the correct levels. Low fluid can cause pump failure, and dirty fluid can damage the system.
   
2. Hydraulic Filter Replacements: Replace the hydraulic filters at regular intervals to ensure the system remains clean and free of contaminants.
   
3. Monitor Hydraulic Pressure: Use a pressure gauge to monitor the system’s pressure regularly. Maintaining proper pressure helps prevent overloading and damage to the pump.
   
4. Keep the System Free from Contaminants: Ensure that the hydraulic fluid is clean, and regularly inspect for leaks. Seal any leaks promptly to avoid fluid loss and contamination.
   

Conclusion
Tandem pump issues on the Case 1845C skid steer can lead to sluggish or unbalanced performance, affecting productivity and efficiency. By regularly checking hydraulic fluid levels, replacing filters, maintaining the proper hydraulic pressure, and inspecting the pump for damage, you can address common issues and keep the system functioning at its best. Preventive maintenance is key to ensuring the longevity and reliability of the tandem pump and the overall hydraulic system. With proper care, your Case 1845C skid steer will continue to perform efficiently for years to come.