JCB 505-20 Noise Under Hydraulic Reservoir Window

[MikePhua]

While operating the JCB 505-20 telehandler, the operator noticed an unusual noise coming from beneath the hydraulic reservoir window. Although the machine was functioning normally in other aspects, this noise raised concerns. To prevent potential damage, the user decided to investigate the source of the sound.
Possible Causes
After initial assessment, it was determined that the issue was likely related to components within the hydraulic system. The noise was specifically happening near the hydraulic reservoir, particularly around the hydraulic pump, piping connections, and the reservoir itself. The potential causes include:

1. Hydraulic Pump Issues: If the hydraulic pump is worn or malfunctioning, it may cause improper fluid flow, which can result in noise.
   
2. Air in the System: Air trapped in the hydraulic fluid can cause bubbling noise, especially in the top portion of the hydraulic reservoir or near the window.
   
3. Low Oil Level or Contaminated Fluid: A low oil level or contaminated hydraulic fluid can also lead to noise, particularly if the pump isn't properly lubricated.
   
4. Loose or Worn Hydraulic Lines: Loose or worn hydraulic lines and connections can cause leaks and abnormal sounds.
   

Troubleshooting Process
The user first checked the hydraulic oil level to ensure it was within the recommended range. The cleanliness of the hydraulic fluid was also inspected, and while there were no visible contaminants, the presence of foam indicated air might be trapped in the system.
Next, the hydraulic lines and connections were thoroughly checked to ensure they were tight and free from any leaks or signs of wear. The hydraulic pump was also listened to closely for any unusual vibrations or noises, but no significant issues were found.
Solution
Based on the findings, the user decided to replace the hydraulic fluid and clean the hydraulic reservoir and filters. After doing so, the system was thoroughly purged of any air bubbles, which seemed to have been the primary cause of the noise.
Upon completing the maintenance, the noise was significantly reduced, and the telehandler returned to normal operation.
Conclusion
The noise coming from under the hydraulic reservoir window of the JCB 505-20 was likely caused by air in the hydraulic fluid, possibly due to old fluid or a minor airlock in the system. Regular maintenance, including changing hydraulic fluid and ensuring the system is free of air bubbles, can help avoid such issues. With proper care, the JCB 505-20 is now operating smoothly again.