Case 850 Dozer Fluid Level Rising in Transmission: Diagnosis and Solutions

[MikePhua]

The Case 850 dozer is a powerful machine commonly used for various construction tasks. However, one issue that operators may encounter is the rising fluid levels in the transmission. This problem could lead to inefficient operation and potential damage to the machine's transmission system if not addressed promptly. This article explores the common causes and solutions for the rising fluid levels in the transmission of a Case 850 dozer.
Common Causes of Rising Fluid Levels in Transmission

1. Hydraulic System Leaks
   One of the most common causes of rising fluid levels is hydraulic system leaks. These leaks can occur in the transmission or other hydraulic components, allowing fluid to enter the transmission system. Over time, this excess fluid accumulates, raising the fluid levels in the transmission. It's important to thoroughly inspect the hydraulic system for any leaks in hoses, seals, and joints.
   
2. Faulty Transmission Breather
   The transmission breather allows air to escape and enter the transmission, preventing pressure buildup. If the breather is clogged or malfunctioning, it can cause a buildup of pressure, which can push hydraulic fluid into the transmission. This can result in an overfilled transmission. Inspect the transmission breather for blockages and ensure it's functioning properly.
   
3. Overfilled Fluid Reservoir
   Sometimes the fluid level may rise due to an overfilled fluid reservoir. If too much hydraulic fluid is added during maintenance or fluid replacement, it can spill over into the transmission, causing the fluid level to rise. Always ensure that the fluid level is within the manufacturer’s specified range when filling the reservoir.
   
4. Faulty Seals or Gaskets
   Worn-out seals or gaskets in the hydraulic system can allow hydraulic fluid to bypass and enter the transmission. Over time, this can lead to an increase in fluid levels. Inspect seals and gaskets for signs of wear or leaks and replace them as necessary.
   
5. Contaminated Fluid
   Contaminated hydraulic fluid can cause abnormal pressure or viscosity changes, leading to improper fluid flow and potential fluid level fluctuations. This can ultimately cause fluid levels in the transmission to rise. Ensure that the hydraulic fluid is clean and meets the manufacturer's specifications.
   
6. Faulty Pump or Hydraulic System Pressure Issues
   A malfunctioning hydraulic pump or abnormal hydraulic pressure can cause excessive fluid to flow into the transmission. This might occur if the pump is providing too much fluid or the system’s pressure is not balanced. Check the hydraulic pump and pressure relief valves to ensure they are working as intended.
   

Troubleshooting Steps

1. Check for Hydraulic Leaks
   Begin by inspecting the entire hydraulic system for any visible leaks. Look for signs of fluid dripping or pooling around hoses, seals, and components. If leaks are found, address them promptly to prevent further fluid from entering the transmission.
   
2. Inspect the Transmission Breather
   Check the transmission breather for blockages or damage. A clogged breather can lead to pressure buildup, causing fluid to move into the transmission. Clean or replace the breather if necessary to restore proper air circulation.
   
3. Verify Fluid Level in Reservoir
   Ensure that the hydraulic fluid reservoir is not overfilled. Refer to the machine's manual for the correct fluid level specifications and adjust as needed. If the fluid level is too high, drain the excess fluid to bring it within the recommended range.
   
4. Inspect Seals and Gaskets
   Examine the hydraulic seals and gaskets for any signs of wear or damage. Leaky seals can allow fluid to bypass and enter the transmission, causing the fluid levels to rise. Replace any faulty seals or gaskets to restore proper fluid containment.
   
5. Check Hydraulic Fluid Quality
   Check the hydraulic fluid for contamination, such as dirt, debris, or moisture. If the fluid appears contaminated, flush the system and replace the old fluid with fresh, clean hydraulic fluid that meets the manufacturer’s specifications.
   
6. Test Hydraulic Pump and Pressure
   Inspect the hydraulic pump for proper function. Check the pressure relief valves to ensure they are not malfunctioning and that the hydraulic pressure is within the specified range. Replace any faulty components in the hydraulic system to maintain proper fluid circulation.
   

Solutions

1. Repair Hydraulic Leaks
   If leaks are found in the hydraulic system, repair or replace the damaged hoses, seals, or components to prevent further fluid leakage into the transmission.
   
2. Replace or Clean the Transmission Breather
   If the transmission breather is clogged, clean it thoroughly or replace it with a new one. This will help prevent pressure buildup and fluid transfer into the transmission.
   
3. Adjust Fluid Levels
   If the fluid reservoir was overfilled, drain the excess fluid to bring the level within the recommended range. Regularly monitor fluid levels during routine maintenance to avoid overfilling.
   
4. Replace Worn Seals and Gaskets
   Replace any worn-out seals or gaskets in the hydraulic system. This will help prevent hydraulic fluid from bypassing and entering the transmission.
   
5. Replace Contaminated Fluid
   If the hydraulic fluid is contaminated, replace it with fresh, clean fluid. Ensure the new fluid is compatible with the machine's requirements and properly filtered to prevent future contamination.
   
6. Replace Faulty Hydraulic Components
   If the hydraulic pump or pressure regulation components are found to be faulty, replace them promptly. This will ensure proper fluid circulation and prevent fluid buildup in the transmission.
   

Conclusion
The rising fluid levels in the transmission of the Case 850 dozer are usually a result of hydraulic system issues, including leaks, faulty breathers, overfilled reservoirs, worn seals, and contaminated fluid. By performing a thorough inspection and addressing these common causes, operators can prevent this issue from escalating into more severe mechanical failures. Regular maintenance, proper fluid handling, and monitoring of the hydraulic system are essential to keep the Case 850 dozer running smoothly. If the problem persists despite these efforts, it is advisable to consult a professional technician for further diagnosis and repair.