Troubleshooting Auxiliary Hydraulic Problems on Bobcat Skid Steers

[MikePhua]

The auxiliary hydraulic system on Bobcat skid steers plays a crucial role in operating attachments such as augers, brooms, and brush cutters. When the auxiliary hydraulics aren't working as expected, it can severely limit the machine’s versatility and performance. This article dives into the common problems that can occur with the auxiliary hydraulics on Bobcat machines and offers troubleshooting tips to help you get back to work quickly.
Understanding the Auxiliary Hydraulic System
The auxiliary hydraulic system on a Bobcat skid steer is designed to provide power to various attachments, making it one of the most versatile features of the machine. Unlike the standard lift and tilt hydraulics, the auxiliary hydraulics deliver higher flow and pressure to operate specialized equipment.
Here’s how it works:

• Hydraulic Pump: Powered by the engine, the pump generates hydraulic pressure.
  
• Control Valve: This valve directs hydraulic fluid to the appropriate attachment, allowing the operator to control the function of tools like a hydraulic breaker, grapple, or trenching bucket.
  
• Quick Couplers: These are used to connect and disconnect hydraulic hoses to various attachments.
  
• Hydraulic Lines and Filters: These components carry fluid throughout the system and ensure that it is filtered and kept clean.
  

While the system is designed for heavy-duty use, it’s important to regularly maintain and troubleshoot common issues to avoid unnecessary downtime.
Common Auxiliary Hydraulic Problems and Troubleshooting
There are several common issues that operators may encounter with their Bobcat skid steers’ auxiliary hydraulic systems. Here's a breakdown of these problems and how to fix them:
1. Low Hydraulic Power or Flow
Symptoms:

• The attached hydraulic tool or attachment doesn’t operate with full power or efficiency.
  
• The hydraulic attachments seem sluggish or respond slowly.
  
• The attachment does not move at all, even when the controls are activated.
  

Possible Causes:

• Low Fluid Levels: One of the simplest causes of low hydraulic power is low fluid in the system. This reduces the overall flow to the attachment.
  
• Clogged Hydraulic Filter: If the hydraulic filter is clogged, it can restrict the flow of hydraulic fluid, leading to weak performance.
  
• Damaged Hydraulic Lines: Leaks or kinks in the hydraulic lines can also prevent the full flow of fluid to the attachment.
  
• Worn Hydraulic Pump: Over time, the hydraulic pump may wear out, leading to decreased efficiency.
  

Solution:

• Check the Fluid: Start by checking the hydraulic fluid level. Ensure that it is topped off with the appropriate fluid and has no signs of contamination.
  
• Inspect the Filter: Clean or replace the hydraulic filter if it appears clogged or dirty.
  
• Check for Leaks: Inspect the hydraulic lines for any visible damage or leaks. Replace any worn hoses or fittings.
  
• Test the Pump: If the system is still underperforming, the pump may need to be tested or replaced by a professional.
  

2. Hydraulic Fluid Leaks
Symptoms:

• Noticeable pools of hydraulic fluid under the skid steer.
  
• A drop in hydraulic pressure or performance during operation.
  

Possible Causes:

• Damaged Hoses or Seals: Over time, hydraulic hoses and seals wear out, causing leaks in the system.
  
• Loose Fittings: Loose connections between hoses and fittings may cause fluid to leak during operation.
  

Solution:

• Tighten Fittings: Inspect all hydraulic connections and tighten any loose fittings.
  
• Replace Worn Seals: If there is a significant leak in a specific area, such as around a cylinder or quick coupler, the seals might need replacing.
  
• Inspect the Hoses: Check hoses for cracks, abrasions, or other signs of damage. Replace any damaged hoses to stop leaks.
  

3. Auxiliary Hydraulics Not Engaging
Symptoms:

• The auxiliary hydraulics will not engage or activate the attachment, despite moving the control lever.
  

Possible Causes:

• Faulty Solenoid Valve: The solenoid valve controls the flow of hydraulic fluid to the auxiliary circuit. If this valve fails, the hydraulic system cannot function properly.
  
• Electrical Issue: On newer Bobcat models, the auxiliary hydraulics are controlled electronically. Issues with the electrical system, such as a blown fuse or bad connection, can prevent the system from engaging.
  
• Clogged Hydraulic Lines: If there’s a blockage in the hydraulic lines or quick couplers, the fluid cannot flow properly to the attachment.
  

Solution:

• Check the Electrical System: Verify that the solenoid and associated wiring are intact. Test the system for power and check for blown fuses.
  
• Inspect the Solenoid Valve: The solenoid valve should be cleaned or replaced if it’s malfunctioning.
  
• Clear Hydraulic Lines: Ensure there are no blockages in the hydraulic lines or quick couplers that could restrict fluid flow.
  

4. Attachment Not Detaching
Symptoms:

• The auxiliary attachment will not detach from the skid steer, even after disengaging the hydraulic control.
  

Possible Causes:

• Pressure Build-Up: Sometimes, pressure can build up in the hydraulic lines, causing difficulty when trying to disconnect the attachment.
  
• Quick Coupler Malfunction: The quick couplers that connect the hoses to the attachment may be damaged or worn out, preventing easy detachment.
  

Solution:

• Relieve Hydraulic Pressure: Before trying to remove the attachment, relieve the hydraulic pressure by activating the hydraulic controls briefly. This should allow for easier detachment.
  
• Inspect the Quick Couplers: Ensure that the quick couplers are functioning properly. If they are damaged or difficult to engage, they may need to be replaced.
  

5. Overheating of the Hydraulic System
Symptoms:

• The hydraulic system or fluid reservoir becomes excessively hot.
  
• The machine shows signs of reduced performance or warning lights for high temperature.
  

Possible Causes:

• Low Fluid Levels: Insufficient fluid can cause the hydraulic system to overheat.
  
• Faulty Hydraulic Cooler: The hydraulic cooler may be malfunctioning or clogged, preventing the system from dissipating heat properly.
  
• Overworking the Loader: If the auxiliary hydraulics are constantly under heavy load, it can cause overheating.
  

Solution:

• Check Fluid Levels: Ensure that the hydraulic fluid is at the proper level. Add fluid as needed, and check for contamination.
  
• Inspect the Cooler: Clean or replace the hydraulic cooler if it is clogged or damaged.
  
• Limit Heavy Loads: Avoid operating the auxiliary hydraulics under excessive loads for prolonged periods.
  

Maintenance Tips to Prevent Auxiliary Hydraulic Problems

• Regular Fluid Changes: Regularly change the hydraulic fluid as recommended by the manufacturer. Old, dirty fluid can cause clogging and wear on components.
  
• Use the Right Attachments: Always use compatible attachments with the proper hydraulic pressure and flow requirements to avoid damaging the system.
  
• Inspect Hydraulic Hoses: Check hoses for wear and tear, as they are susceptible to damage from abrasions, pressure, and age.
  
• Clean Quick Couplers: Regularly clean the quick couplers to avoid dirt or debris getting into the hydraulic system.
  

Conclusion
The auxiliary hydraulic system on Bobcat skid steers is essential for powering attachments and enhancing the versatility of the machine. When problems arise with the hydraulic system, it can lead to reduced performance and downtime. By regularly inspecting and maintaining the system, and by quickly addressing issues like low flow, leaks, and hydraulic engagement, operators can keep their Bobcat equipment running smoothly and efficiently.
Regular maintenance, early detection, and proper troubleshooting techniques are key to avoiding expensive repairs and maximizing the lifespan of the auxiliary hydraulic system on your Bobcat skid steer.