Gehl 6640 No Drive and Slow Hydraulics Troubleshooting

[MikePhua]

When dealing with issues like no drive and slow hydraulics on a Gehl 6640 skid steer, there are a few potential causes and troubleshooting steps to follow. Here's a general guide on how to diagnose and address the problem.
Possible Causes

1. Hydraulic Fluid Levels and Quality
   One of the first things to check is the hydraulic fluid levels. If the fluid is low, it can cause poor hydraulic performance. Ensure the fluid is at the recommended level and check for any signs of contamination. If the fluid is dirty or degraded, it may need to be replaced.
   
2. Hydraulic Pump Issues
   A malfunctioning hydraulic pump can lead to slow or inadequate hydraulic performance. If the pump is not generating the proper pressure, the hydraulics won't function as expected. This could be caused by wear and tear or internal damage.
   
3. Hydraulic Filters and Valves
   Blocked filters or malfunctioning hydraulic valves can restrict the flow of fluid, leading to slow operation or loss of drive. Inspect and clean or replace the hydraulic filters. If the problem persists, check the valves for blockages or malfunction.
   
4. Drive Motor Problems
   If the skid steer has no drive, the drive motors may be at fault. Check for any signs of damage or wear in the drive motor. If the motor is malfunctioning, it may need to be repaired or replaced.
   
5. Electrical or Sensor Issues
   Some electrical problems, such as faulty sensors or wiring, can cause issues with hydraulic performance or drive. Check the wiring and sensors related to the hydraulic and drive systems for any visible issues.
   
6. Check for Leaks
   Hydraulic system leaks are another common cause of slow hydraulics or no drive. Inspect the hydraulic hoses and connections for any signs of leakage. Even small leaks can significantly affect system performance.
   

Troubleshooting Steps

1. Check Fluid Levels
   Ensure the hydraulic fluid is at the proper level and is clean. Top up or replace the fluid if necessary.
   
2. Inspect Hydraulic Pump and Filters
   Look for signs of damage or wear on the hydraulic pump. Clean or replace filters if they are clogged.
   
3. Test Drive Motors
   If there is no drive, inspect the drive motors for any issues. Look for signs of damage or wear that may require replacement.
   
4. Inspect Electrical Components
   Check for any electrical issues, including wiring problems or faulty sensors. Replace any defective components.
   
5. Look for Leaks
   Carefully inspect the hydraulic lines for leaks and repair or replace damaged hoses or fittings.
   

By following these steps, you should be able to identify the source of the problem and take appropriate action to fix it. If the issue persists, consulting a professional technician or the service manual may be necessary.