Troubleshooting Loud Noise in Bobcat 570: Diagnosing Arm Drop Issues

[MikePhua]

Introduction: Understanding the Importance of Machine Noise Diagnosis
Heavy machinery like the Bobcat 570 is designed to withstand tough working conditions. However, persistent issues such as strange noises during operation can indicate underlying mechanical problems that, if left unchecked, could lead to costly repairs or machine downtime. One such issue that operators often encounter is a loud noise coming from the right side of the machine when the arm is being lowered.
In this article, we will explore the common causes of such noises in the Bobcat 570, how to diagnose the problem, and potential solutions to restore the machine’s smooth operation.
Common Causes of Noises During Arm Movement

1. Hydraulic System Problems
   The most likely cause of loud noises when lowering the arm on a Bobcat 570 is an issue within the hydraulic system. This system is responsible for powering the lifting and lowering of the arm, and any imbalance or malfunction can lead to noticeable noise, such as grinding, whining, or hissing sounds.
   • Possible Causes:
     • Low Hydraulic Fluid Levels: If the hydraulic fluid is too low, the pump may struggle to supply sufficient power, causing it to make loud noises as it works harder to move the arm.
       
     • Contaminated Hydraulic Fluid: Dirt, moisture, or air in the hydraulic fluid can cause the hydraulic components to malfunction and produce abnormal sounds.
       
     • Faulty Hydraulic Pump: A damaged or worn-out hydraulic pump could also be the culprit, as it fails to generate adequate pressure.
       
   • Solution: Begin by checking the hydraulic fluid levels and topping them up if necessary. Ensure the fluid is clean and free of contaminants, and replace it if it appears dirty or thick. Inspect the hydraulic lines for any visible damage, and verify that the pump is operating as it should. If the pump is damaged, it may require rebuilding or replacement.
     
2. Worn or Loose Components
   Over time, components such as pins, bushings, and hydraulic cylinders can become worn or loose, leading to irregular movement and unwanted noise when the arm is being lowered. This wear and tear may result in a grinding or squeaking sound, especially when the arm reaches the lower end of its travel.
   • Possible Causes:
     • Loose Pins or Bushings: If the pins or bushings that hold the arm components are loose or worn out, they can cause friction or slippage, producing a loud noise.
       
     • Worn Hydraulic Cylinder Seals: A malfunctioning seal in the hydraulic cylinder may allow air or fluid to escape, creating noise during the arm’s lowering action.
       
   • Solution: Inspect the pins and bushings for signs of wear or looseness. If any parts are damaged or excessively worn, they should be replaced. Check the hydraulic cylinders for leaks around the seals and replace any damaged seals. Lubricating the moving parts regularly can also help reduce friction and prevent further wear.
     
3. Air in the Hydraulic System
   If there is air in the hydraulic system, it can cause uneven hydraulic pressure and result in erratic movements and loud noises when the arm is being lowered. Air in the system can occur due to poor sealing, leaks, or improper fluid replacement.
   • Possible Causes:
     • Leaking Fittings: Leaks in the hydraulic system allow air to enter, which disrupts the flow of fluid and can cause loud noises during operation.
       
     • Improper Fluid Change: If the hydraulic fluid is replaced incorrectly or the system is not properly bled, air pockets can form inside the lines, leading to noises.
       
   • Solution: Bleed the hydraulic system to remove any trapped air. Ensure all fittings and connections are properly tightened to avoid leaks, and inspect the system for any cracks or damaged seals. A thorough check of the hydraulic system can help maintain proper fluid flow and eliminate air-related issues.
     
4. Electrical or Control System Malfunctions
   Though less common, issues with the electrical or control system can also lead to erratic or jerky arm movement, which might be accompanied by noise. If the control valve or solenoids are malfunctioning, the hydraulic flow may not be properly regulated, leading to inconsistent movements and noise.
   • Possible Causes:
     • Faulty Control Valves: If the control valves are sticking or malfunctioning, they might cause an irregular flow of hydraulic fluid, leading to noise when the arm is lowered.
       
     • Solenoid Malfunctions: A defective solenoid can prevent the hydraulic flow from being properly directed, resulting in noisy or erratic arm movements.
       
   • Solution: Inspect the control valves and solenoids for any signs of wear or malfunction. These components should be replaced if they are not functioning properly. Regular maintenance and cleaning of the control system can help prevent such issues from occurring.
     

Diagnosing the Issue: Step-by-Step Approach

1. Check Fluid Levels and Quality
   • Start by checking the hydraulic fluid levels and ensuring that the fluid is clean and free from contaminants. Replace the fluid if it looks dirty, and make sure the correct type of hydraulic fluid is used.
     
2. Inspect the Hydraulic Lines and Components
   • Look for any visible signs of damage or leaks in the hydraulic lines, hoses, and cylinders. Tighten any loose fittings and replace any damaged components.
     
3. Examine the Arm’s Pins and Bushings
   • Inspect the pins, bushings, and other pivot points for excessive wear or looseness. Tighten or replace any worn parts to eliminate friction and noise.
     
4. Check for Air in the Hydraulic System
   • If you suspect air in the system, perform a hydraulic bleed to release any trapped air. Ensure all seals are intact and there are no leaks allowing air into the system.
     
5. Test the Control System
   • If the noise persists, inspect the control valves and solenoids for proper operation. Replace or clean these parts as needed to ensure the smooth regulation of hydraulic flow.
     

Preventive Measures: How to Keep Your Bobcat 570 Running Smoothly

1. Regular Fluid Checks
   • Make it a habit to regularly check hydraulic fluid levels and quality. Keep the fluid clean to avoid contamination that can cause internal damage to the hydraulic system.
     
2. Lubricate Moving Parts
   • Lubrication is key to reducing friction between moving parts. Make sure the pins, bushings, and other pivot points are regularly lubricated to prevent wear and reduce noise.
     
3. Routine Inspections
   • Conduct regular inspections of the hydraulic components, hoses, fittings, and cylinders to identify any potential issues before they escalate into more serious problems.
     
4. Follow Manufacturer’s Maintenance Guidelines
   • Adhere to the manufacturer’s maintenance schedule for all systems, including hydraulics, electrical components, and structural elements. This will help prolong the life of the machine and ensure optimal performance.
     

Real-World Example: A Bobcat Operator’s Experience
A Bobcat 570 operator working on a landscaping project in Arizona noticed a loud noise coming from the right side of the machine whenever the arm was lowered. After checking the hydraulic fluid levels and performing a basic inspection, it was discovered that the hydraulic lines had a small leak, allowing air to enter the system and causing the irregular noise. Once the fittings were tightened and the system was properly bled, the issue was resolved, and the machine returned to smooth operation. This experience reinforced the importance of regular maintenance and thorough inspections to avoid costly repairs and ensure machine efficiency.
Conclusion: Keeping Your Bobcat 570 in Top Shape
A loud noise coming from the right side of the Bobcat 570 when lowering the arm is often caused by issues within the hydraulic system, such as low fluid levels, air contamination, or worn components. By following a systematic approach to diagnosing and resolving the issue—starting with fluid checks and moving on to component inspections—operators can ensure their machines are running smoothly.
Regular maintenance, including lubricating moving parts, inspecting hydraulic components, and following the manufacturer’s guidelines, can help prevent such issues and extend the life of your Bobcat 570. With the right care, your machine will continue to provide reliable performance on the job site.