10-10-2025, 03:39 PM
Summary
The Bobcat 873 skid steer is prone to overheating when airflow is restricted by debris buildup, fan inefficiency, or hydraulic system strain. Addressing cooling system cleanliness, fan performance, and hydraulic load is essential to restoring normal operating temperatures.
Bobcat 873 Background and Cooling System Design
The Bobcat 873 was introduced in the late 1990s as a high-performance skid steer loader with a vertical lift path and a Deutz diesel engine. It features a robust hydraulic system, high-flow auxiliary capability, and a rear-mounted cooling package that includes the radiator, hydraulic cooler, and engine oil cooler stacked together.
Bobcat, founded in 1947, has sold hundreds of thousands of skid steers globally. The 873 was part of the 800 series, known for its power and versatility in construction, landscaping, and agricultural applications. However, its rear cooling stack design requires regular cleaning and airflow management to prevent overheating.
Terminology and Common Failure Points
Operators have reported that the 873 overheats after 30–45 minutes of operation, especially under load. The temperature gauge climbs steadily, and the machine may enter limp mode or shut down. Key diagnostic steps include:
One operator in Nebraska found that his 873 overheated during hay stacking. After removing the rear screen and pressure-washing the cooling stack, the issue improved. He later discovered the fan clutch was not engaging fully, and replacing it restored normal temperatures.
Another technician in Georgia noted that the hydraulic cooler fins were packed with clay dust. He used compressed air and a fin comb to restore airflow. He also added a hydraulic fluid cooler bypass valve to reduce system strain during high-flow attachment use.
Preventive Measures and Recommendations
Overheating in the Bobcat 873 is typically caused by airflow restriction, fan inefficiency, or hydraulic overload. By maintaining a clean cooling stack, ensuring proper fan function, and managing hydraulic demand, operators can prevent temperature spikes and extend machine life. These steps are especially critical in high-dust or high-load environments where cooling performance is constantly challenged.
The Bobcat 873 skid steer is prone to overheating when airflow is restricted by debris buildup, fan inefficiency, or hydraulic system strain. Addressing cooling system cleanliness, fan performance, and hydraulic load is essential to restoring normal operating temperatures.
Bobcat 873 Background and Cooling System Design
The Bobcat 873 was introduced in the late 1990s as a high-performance skid steer loader with a vertical lift path and a Deutz diesel engine. It features a robust hydraulic system, high-flow auxiliary capability, and a rear-mounted cooling package that includes the radiator, hydraulic cooler, and engine oil cooler stacked together.
Bobcat, founded in 1947, has sold hundreds of thousands of skid steers globally. The 873 was part of the 800 series, known for its power and versatility in construction, landscaping, and agricultural applications. However, its rear cooling stack design requires regular cleaning and airflow management to prevent overheating.
Terminology and Common Failure Points
- Cooling Stack: The layered arrangement of radiator, hydraulic cooler, and oil cooler at the rear of the machine.
- Hydraulic Load: The pressure and flow demand placed on the hydraulic system, which increases heat generation.
- Fan Shroud: A plastic or metal enclosure that directs airflow through the cooling stack.
- Thermostatic Fan Clutch: A temperature-sensitive mechanism that engages the fan at higher temperatures.
Operators have reported that the 873 overheats after 30–45 minutes of operation, especially under load. The temperature gauge climbs steadily, and the machine may enter limp mode or shut down. Key diagnostic steps include:
- Inspect the cooling stack for debris—grass, dust, and oil residue can block airflow.
- Check the fan blades and shroud for cracks or misalignment. A missing shroud reduces airflow efficiency by up to 40%.
- Test the fan clutch engagement—if the fan spins freely when hot, the clutch may be faulty.
- Monitor hydraulic fluid temperature—high hydraulic temps can contribute to engine overheating.
- Verify coolant level and thermostat function—a stuck thermostat can prevent coolant circulation.
One operator in Nebraska found that his 873 overheated during hay stacking. After removing the rear screen and pressure-washing the cooling stack, the issue improved. He later discovered the fan clutch was not engaging fully, and replacing it restored normal temperatures.
Another technician in Georgia noted that the hydraulic cooler fins were packed with clay dust. He used compressed air and a fin comb to restore airflow. He also added a hydraulic fluid cooler bypass valve to reduce system strain during high-flow attachment use.
Preventive Measures and Recommendations
- Clean the cooling stack weekly in dusty environments.
- Replace the fan clutch every 2,000 hours or when engagement is inconsistent.
- Install a temperature gauge for hydraulic fluid to monitor system heat.
- Use synthetic hydraulic fluid with higher thermal stability.
- Add a reversible fan kit to blow out debris automatically during operation.
Overheating in the Bobcat 873 is typically caused by airflow restriction, fan inefficiency, or hydraulic overload. By maintaining a clean cooling stack, ensuring proper fan function, and managing hydraulic demand, operators can prevent temperature spikes and extend machine life. These steps are especially critical in high-dust or high-load environments where cooling performance is constantly challenged.
