CAT 299D3 Auxiliary Hydraulics 1 and 2 and Continuous Flow Not Working

[MikePhua]

The user discussed an issue with the CAT 299D3 skid steer loader, where the Auxiliary Hydraulics 1 and 2, as well as the Continuous Flow, are not working properly. Hydraulic system failures often affect the operation of attachments such as buckets, cutters, or other hydraulic-driven tools. Therefore, it is crucial to troubleshoot and resolve the issue promptly.
Troubleshooting Steps

1. Check Hydraulic Oil and Oil Level
   When the hydraulic system is not functioning properly, the first step is to check the hydraulic oil level and quality. Low oil levels or poor-quality oil can lead to unstable hydraulic system performance. Check the hydraulic oil in the reservoir, ensuring the oil level is within the normal range and that the oil is not contaminated or degraded. If necessary, top up or replace the hydraulic oil.
   
2. Check Electrical Connections
   The hydraulic system on the CAT 299D3 is integrated with the machine's electronic control system, making the reliability of electrical connections crucial. Inspect the electrical connectors, especially those connected to the hydraulic control valves, for loose, corroded, or damaged connections. Faulty electrical connections may prevent the hydraulic system from receiving the correct signals, causing it to malfunction.
   
3. Check the Hydraulic Control Valve
   The hydraulic control valve is a key component in managing the auxiliary hydraulic functions. Inspect the hydraulic control valve to ensure it is operating correctly, without sticking or damage. Clean or replace any faulty valves to ensure smooth hydraulic flow through the system.
   
4. Check Flow Adjustment Settings
   The CAT 299D3 is equipped with flow adjustment capabilities to control hydraulic flow to the attachments. If the flow rate is not correctly set, the auxiliary hydraulics may not provide sufficient power. Check the machine’s hydraulic flow settings and verify that they are correctly adjusted for the attachments being used. If needed, reset the flow to match the attachment requirements.
   
5. Check Hydraulic Pump and Motor
   The hydraulic pump and motor are essential components of the hydraulic system. If the pump is malfunctioning or the motor fails, the hydraulic system may not work as expected. Check the hydraulic pump’s pressure output to ensure it is within the normal range. If issues with the pump or motor are found, they may need to be repaired or replaced.
   

Solutions

1. Top Up or Replace Hydraulic Oil
   If the hydraulic oil is low or of poor quality, first top it up or replace it with the appropriate hydraulic oil. Regularly check the oil quality to maintain proper hydraulic system performance.
   
2. Repair Electrical Connections
   Ensure that all electrical connections are secure and free from corrosion or damage. If needed, clean or replace electrical connectors to ensure proper signal transmission.
   
3. Clean or Replace Hydraulic Control Valve
   Clean or replace the hydraulic control valve to ensure it is functioning correctly and that hydraulic flow is uninterrupted.
   
4. Re-adjust Hydraulic Flow Settings
   Check and adjust the hydraulic flow settings to ensure the attachment receives the correct amount of hydraulic power. Reset the flow as needed to match the attachment’s requirements.
   
5. Repair or Replace Hydraulic Pump and Motor
   Check the hydraulic pump and motor for proper operation. If issues with the pump or motor are found, repair or replace the damaged components to restore hydraulic system functionality.
   

Conclusion
The failure of the auxiliary hydraulics (Auxiliary 1 and 2) and continuous flow on the CAT 299D3 skid steer loader can be caused by several factors, including low hydraulic oil, electrical connection issues, faulty hydraulic control valves, improper flow settings, or damaged hydraulic pumps and motors. By systematically checking the hydraulic oil, electrical connections, control valves, flow settings, and hydraulic pump and motor, the issue can be diagnosed and resolved. Regular maintenance of the hydraulic system will ensure smooth operation and extend the lifespan of the equipment.