1979 Case 850B Dozer: Overview and Maintenance Insights

[MikePhua]

The 1979 Case 850B Dozer is part of Case's long history of manufacturing durable and powerful construction equipment. Known for its exceptional performance in heavy-duty tasks such as grading, pushing, and land clearing, the 850B dozer offers a solid combination of horsepower, maneuverability, and reliability. While it was originally designed to meet the needs of the construction industry, its rugged build and versatility have made it a favorite for a wide range of projects over the years.
This article aims to provide a detailed overview of the 1979 Case 850B Dozer, discussing its specifications, common issues, maintenance tips, and troubleshooting strategies to keep this robust machine running smoothly for years to come.
Introduction to the Case 850B Dozer
The Case 850B Dozer was introduced in the late 1970s and quickly became known for its reliability and powerful performance. Part of the Case 850 series, the 850B was designed to meet the demanding needs of contractors and operators in the construction, agriculture, and forestry sectors. Over time, this dozer earned a reputation for its strong hydraulic system, ease of operation, and cost-effectiveness.
The 850B was equipped with a 6-cylinder, naturally aspirated engine that provided substantial power for its size. With an efficient transmission system and a variety of blade options, the 850B was capable of tackling tough jobs such as land clearing, road building, and large-scale grading projects.
Specifications of the 1979 Case 850B Dozer
Understanding the specifications of the Case 850B is important for both operators and mechanics to ensure proper operation and maintenance. Key specifications for this model include:

• Engine: 6-cylinder diesel engine
  
• Horsepower: Approximately 90-100 HP (depending on the version)
  
• Operating Weight: Around 20,000 pounds (varies with blade configuration)
  
• Blade Options: Straight, semi-U, and full-U blades
  
• Hydraulic System: Open-center hydraulic system, capable of handling a variety of attachments
  
• Transmission: Powershift transmission with multiple forward and reverse gears
  
• Fuel Capacity: Approximately 50 gallons (190 liters)
  

The 850B was designed to be a versatile, mid-sized dozer, striking a balance between power and agility. It was used for both heavy construction and lighter tasks, proving to be a workhorse in the field.
Common Issues with the Case 850B Dozer
Despite its rugged build, the 1979 Case 850B Dozer, like any heavy machinery, is prone to certain issues. These can range from minor wear and tear to more complex mechanical failures. Below are some of the most common problems reported by operators:

1. Transmission and Shifting Problems
   One of the more common issues reported with the Case 850B Dozer is difficulty with shifting or a sluggish response from the transmission. This can result in delayed movement, jerky operation, or even total loss of power in some cases.
   • Solution: The transmission fluid should be checked regularly for proper levels and cleanliness. Low fluid levels or old, contaminated fluid can cause shifting problems. In some cases, it may be necessary to clean or replace the transmission filters to restore proper function.
     
2. Hydraulic System Failures
   The 850B Dozer relies heavily on its hydraulic system for blade control and other attachment operations. Over time, hydraulic hoses and seals can wear out, leading to oil leaks or diminished hydraulic pressure. This can result in slower blade movement, reduced lifting power, or complete hydraulic failure.
   • Solution: Inspect hydraulic hoses and fittings regularly for leaks, cracks, or signs of wear. Ensure that hydraulic fluid levels are maintained, and replace any damaged hoses or seals as necessary. Regular maintenance of the hydraulic pump and filters is also recommended.
     
3. Cooling System Overheating
   Overheating can be an issue on older dozers, especially if the cooling system has not been properly maintained. A clogged radiator, low coolant levels, or a malfunctioning fan can lead to overheating, which can damage the engine and other critical components.
   • Solution: Check the radiator for debris or dirt that might obstruct airflow. Ensure that the coolant is topped up and that the cooling fan operates correctly. If overheating persists, inspect the water pump and thermostat for any defects.
     
4. Engine Power Loss
   A reduction in engine power can be caused by a number of factors, such as clogged fuel filters, dirty air filters, or poor fuel quality. In some cases, the fuel injectors may need cleaning or replacing if they are causing engine misfires.
   • Solution: Replace the fuel and air filters regularly. Make sure to use high-quality fuel to avoid contaminants. If engine power continues to decrease, inspect the injectors and consider cleaning or replacing them.
     
5. Electrical Failures
   As with most older equipment, electrical issues can arise in the Case 850B. This may include problems with the starter motor, battery, or alternator, all of which are essential for starting and maintaining engine operation.
   • Solution: Test the battery voltage and check for any signs of corrosion on the terminals. If the battery is old or not holding a charge, consider replacing it. Check the alternator and starter motor for proper operation and replace any defective electrical components.
     

Routine Maintenance for the Case 850B Dozer
Regular maintenance is essential to keep the Case 850B Dozer operating at peak performance. Below are some key maintenance practices that should be performed on a regular basis:

1. Engine Maintenance
   • Check and replace engine oil at recommended intervals.
     
   • Replace air filters regularly, especially if operating in dusty conditions.
     
   • Inspect the fuel system for leaks and clean or replace fuel filters.
     
2. Hydraulic System
   • Regularly check hydraulic fluid levels and ensure proper operation.
     
   • Replace hydraulic filters and hoses as needed.
     
   • Inspect and clean the hydraulic pump for efficient performance.
     
3. Cooling System
   • Clean the radiator and cooling fan to prevent overheating.
     
   • Check coolant levels and replace coolant if necessary.
     
   • Inspect the water pump and thermostat for any malfunction.
     
4. Transmission
   • Monitor transmission fluid levels and quality.
     
   • Change transmission fluid and clean the filters at recommended intervals.
     
   • Inspect the transmission for leaks and damaged seals.
     
5. Undercarriage and Tracks
   • Regularly inspect the tracks for wear and proper tension.
     
   • Replace track pads if they are worn or damaged.
     
   • Clean the undercarriage to prevent dirt buildup and ensure smooth operation.
     
6. Electrical System
   • Test the battery regularly to ensure it is holding a charge.
     
   • Check electrical connections for signs of corrosion or wear.
     
   • Ensure that all lights and signals are functioning properly.
     

Troubleshooting Tips
When issues arise with the 850B Dozer, a methodical approach to troubleshooting is essential:

1. Loss of Power or Engine Hesitation: Check the air filter, fuel filter, and fuel quality. Replace filters if needed and ensure proper fuel flow.
   
2. Sluggish Hydraulic System: Inspect hydraulic fluid levels and replace any damaged hoses or seals.
   
3. Transmission Issues: Inspect fluid levels and check for leaks. Consider replacing the transmission filter if shifting issues persist.
   
4. Overheating: Check coolant levels and clean the radiator. Inspect the water pump and thermostat for signs of failure.
   

Conclusion
The 1979 Case 850B Dozer remains a reliable and durable piece of equipment despite its age. By understanding the common issues associated with this model and performing regular maintenance, operators can extend the life of the machine and ensure it continues to perform at a high level. Whether you're working on a construction site, clearing land, or involved in other heavy-duty tasks, the Case 850B remains a solid choice for operators who need a dependable dozer. Regular inspections, maintenance, and prompt attention to issues will help keep this iconic piece of machinery running smoothly for many more years to come.