On Panswork, a user reported an issue with their AVS HD 4520 heavy equipment suddenly shutting down while operating. The user explained that the machine suddenly stalled during normal operation and couldn't be restarted, causing a work stoppage. This issue led to a broad discussion with many users sharing their experiences, discussing possible causes, and offering solutions for resolving the problem.
Problem Description
The user described the equipment suddenly shutting down while running. Although the fuel system, cooling system, and electrical system appeared to be in good condition, the machine could not be restarted after stalling. The user checked the starter battery, electrical connections, and fuel system, but the problem persisted. Upon further testing, the user found that the equipment was completely unresponsive.
Possible Causes of the Issue
In the discussion, users suggested several possible causes for the sudden shutdown of the AVS HD 4520:

1. Fuel System Issues
   Fuel system problems are a common cause of machine stalling. Some users speculated that a malfunctioning fuel pump or injectors could be preventing proper fuel delivery. If the fuel filter or fuel lines are clogged, the machine may fail to operate normally.
   
2. Electrical System Problems
   Another common issue is electrical system failure, which includes low battery voltage, loose electrical connections, or short circuits. If the battery voltage is low or there is a problem with the wiring, the equipment could suddenly shut down during operation and may not restart.
   
3. Sensor Malfunction
   Some users pointed out that sensor malfunctions might also cause the equipment to stall. For instance, if the Engine Control Module (ECM) sensors detect incorrect signals, they might shut off fuel delivery or stop the engine to protect the machine. Checking the functionality of the sensors is an essential step in diagnosing the issue.
   
4. Overheating Problems
   Overheating during extended operation could cause the engine to automatically shut down to prevent damage. Some users believed that a malfunctioning cooling system, such as low coolant levels or a clogged radiator, might lead to overheating and trigger the shutdown.
   

1. Check and Replace the Battery
   Ensure that the battery voltage is adequate and check the electrical connections for any loose or damaged wiring. If the battery is old or the voltage is low, it’s recommended to replace it to ensure proper startup and operation.
   
2. Inspect the Fuel System
   Check the fuel filter, fuel pump, and injectors to ensure proper fuel delivery. If the fuel pump or filter is faulty, replace them. Also, check the fuel lines for any blockages or leaks.
   
3. Check the Sensors and ECM
   Use diagnostic tools to check the Engine Control Module (ECM) and sensors for any faults. If error codes are found, further analysis should be done, and faulty sensors should be replaced.
   
4. Inspect the Cooling System
   Check the coolant levels and radiator for any issues. If the radiator is clogged or the coolant levels are low, it’s important to address these problems to prevent overheating and engine shutdown.
   

1. Issue Overview
On the Panswork forum, a user reported issues with the auxiliary electrical plug on their Bobcat T190 skid-steer loader. The user stated that their machine is unable to properly connect to auxiliary equipment, with the electrical plug not functioning correctly or failing to work altogether. This issue is likely related to electrical connections or a damaged plug, and it requires troubleshooting to identify and resolve.
2. Common Causes

1. Damaged Electrical Plug
   • The auxiliary electrical plug on the Bobcat T190 may be damaged due to extended use or frequent connecting and disconnecting. The contact points of the plug may suffer from corrosion or wear, preventing a proper electrical connection.
     
2. Loose Electrical Connections
   • If the plug is not securely connected to the machine’s electrical interface, it can cause signal loss or insufficient power, preventing the auxiliary function from operating. Loose electrical connections are a common cause of failure in these types of systems.
     
3. Incompatible Plug with Equipment
   • Users may encounter situations where the electrical plug is not compatible with equipment from different brands or models. The electrical interface of certain equipment may not align with the standard plug used by the Bobcat T190, leading to connection issues or non-functionality.
     
4. Electrical System Failure
   • A failure in the electrical system of the Bobcat T190, such as issues with the electrical control module, wiring, or fuses, can also prevent the auxiliary electrical plug from working. A full inspection of the electrical system is necessary to rule out any potential faults.
     

1. Check the Plug and Electrical Connections
   • Perform a visual inspection of the electrical plug and connections, looking for signs of damage, wear, or corrosion. If any issues are found, clean the contacts or replace the plug to restore proper functionality.
     
2. Ensure a Secure Connection
   • Inspect the connection between the plug and the electrical interface to make sure there is no looseness or poor contact. Reconnect or securely fasten the plug to ensure a tight fit.
     
3. Check Compatibility
   • If you are using third-party equipment or attachments, check whether the plug is compatible with the Bobcat T190’s standard electrical interface. If it is incompatible, you may need to replace the plug or use an adapter to make it work.
     
4. Inspect the Electrical System
   • If the plug appears to be fine, move on to inspecting the entire electrical system of the Bobcat T190. Check the electrical control module, wiring, fuses, and other components to ensure everything is functioning correctly. If any faults are found, address them accordingly.
     

On Panswork, a user shared their experience with the Bobcat 751 skid steer encountering several issues, particularly with starting and power loss. The machine had difficulty starting, especially in colder weather, and even when it did start, the engine's performance was below expectations, leading to reduced efficiency. This sparked a broad discussion, with many users sharing their own experiences and solutions to help others diagnose and fix similar problems.
Common Issues and Symptoms
The most commonly reported problems with the Bobcat 751 included difficulty starting and power loss. Users noted that the machine struggled to start, particularly in cold weather. Even when it did start, the engine’s performance was far from ideal, with insufficient power output, which affected normal operation. Some users also mentioned that after starting, the machine would run unevenly and sometimes even stall.
Possible Causes of the Issue
Here are some of the potential causes discussed by users that could lead to these problems:

1. Battery and Electrical System Failures
   Many users believe that the difficulty starting the machine is related to insufficient battery voltage or electrical system faults. The Bobcat 751 may struggle to start if the battery is old or has been used for a long time, leading to inadequate starting voltage. Without sufficient current from the battery, the machine may either fail to start or fail to run properly once it starts.
   
2. Fuel System Problems
   Fuel supply issues are another common cause of engine starting problems. Some users found that a clogged fuel filter, faulty fuel pump, or malfunctioning fuel injectors could all affect engine startup and performance. Any issue in the fuel system can lead to unstable fuel delivery, impacting the engine's normal operation.
   
3. Air Filter and Intake System Issues
   A clogged air filter or a leaking intake system can cause insufficient airflow to the engine, affecting its combustion efficiency. Some users mentioned that when the air filter is dirty or blocked, the engine can’t get enough air, leading to difficulty starting and reduced power.
   
4. Cold Starting Issues
   Some users pointed out that the Bobcat 751 has difficulty starting in low temperatures, especially in colder climates. Cold starting problems are often linked to inadequate engine preheating or oil that is too thick, making it harder for the engine to start or leading to stalling.
   

1. Check the Battery and Electrical System
   Ensure that the battery has sufficient voltage and check the electrical connections for any loose or damaged wiring. Users recommended regular inspection of the battery and electrical system, especially before cold weather, to ensure enough starting current is available.
   
2. Clean or Replace the Fuel Filter
   Check and replace the fuel filter to ensure smooth fuel delivery. If issues with the fuel pump or injectors are found, they should be repaired or replaced to restore proper fuel system functionality.
   
3. Replace the Air Filter
   Regularly inspect the air filter to ensure it isn’t clogged with dust or debris. If the air filter is dirty, it should be replaced to maintain airflow and ensure the engine runs efficiently.
   
4. Use Appropriate Oil for Cold Weather
   For cold starting issues, users suggested using oil that is suitable for colder temperatures, as this reduces the oil’s viscosity, making it easier for the engine to start.
   

1. Issue Overview
On the Panswork forum, a user reported electrical issues with their Bobcat 863 skid-steer loader, causing the auxiliary hydraulic function to be inoperative. Specifically, while the main hydraulic system functions normally, the auxiliary hydraulic system fails to activate. This issue likely stems from a problem with the electrical system, and it requires troubleshooting and resolution.
2. Common Causes

1. Electrical Connection Issues
   • Loose or poor electrical connections can prevent the auxiliary hydraulic system from receiving the necessary electrical signals to operate. Common problem areas include connectors, terminals, and switches that may suffer from corrosion, wear, or looseness.
     
2. Low Battery Voltage
   • Insufficient battery voltage or a failing battery can disrupt the electrical system, preventing power from reaching various components, including the auxiliary hydraulics. Check the battery's voltage and condition to ensure it is providing adequate power.
     
3. Blown Fuses or Faulty Relays
   • The auxiliary hydraulic system may rely on specific fuses or relays for operation. If any of these components are blown or faulty, they can interrupt the electrical signal flow, preventing the auxiliary hydraulics from activating. Inspect and replace any damaged fuses or relays.
     
4. Faulty Electrical Control Module
   • The Bobcat 863 may have a malfunctioning electrical control module (ECM), which is responsible for transmitting electrical signals to the auxiliary hydraulic system. If the ECM is not functioning correctly, it could fail to send the proper signals. In this case, the ECM may need to be repaired or replaced.
     
5. Shorted or Damaged Wiring
   • Damaged or short-circuited electrical wires can disrupt the flow of electrical signals, preventing the auxiliary hydraulics from operating. A thorough inspection of the wiring is necessary to identify any faults.
     

1. Check Electrical Connections
   • Inspect all electrical connections, including connectors, terminals, and switches, for any loose or corroded parts. If any issues are found, clean or reconnect the components to ensure proper electrical contact.
     
2. Check Battery Voltage
   • Use a multimeter to check the battery voltage to ensure it is within the correct range for starting the electrical system. If the voltage is low, recharge the battery or replace it if necessary.
     
3. Inspect Fuses and Relays
   • Refer to the user manual to locate the fuses and relays that control the auxiliary hydraulics. Check for any blown fuses or faulty relays and replace them as needed.
     
4. Check the Electrical Control Module
   • If the problem persists, the ECM may be at fault. Use diagnostic tools to check for any error codes or malfunctions. If the ECM is identified as faulty, consider repairing or replacing it.
     
5. Inspect Electrical Wiring
   • Carefully inspect the electrical wiring for signs of damage, short circuits, or wear. Repair or replace any damaged wiring to restore proper signal transmission.
     

In a discussion on Panswork, a user reported an issue with their CAT 246D skid steer where oil was found in the antifreeze reservoir. This type of problem usually indicates an internal fault within the machine’s cooling system or engine, potentially leading to more serious damage if not addressed. The issue sparked a broad conversation about the causes and solutions for this kind of problem, with many users sharing their experiences and advice for diagnosing and fixing the issue.
Cause Analysis
The presence of oil in the antifreeze reservoir typically results from one of the following causes:

1. Oil Cooler Leak
   The CAT 246D is equipped with an oil cooler, which uses coolant to help regulate the temperature of the engine oil. If the oil cooler leaks, engine oil and coolant can mix, leading to oil appearing in the antifreeze reservoir. This is one of the most common causes of this issue, as the oil cooler operates under high heat and pressure, making it prone to cracks or corrosion.
   
2. Engine Seal Failure
   Another potential cause is a failure in the engine’s internal seals. If the seals on components such as the water pump or oil pump fail, oil and coolant can mix through leaks. While less common, this issue can cause oil to enter the coolant system.
   
3. Heat Exchanger Failure
   In some cases, a faulty heat exchanger can cause direct mixing of coolant and engine oil. Although rare, if the heat exchanger fails, it may allow oil and coolant to pass into each other's systems.
   

1. Replacing the Oil Cooler
   Most users recommended inspecting and replacing the oil cooler, as this is often the primary cause of coolant and oil mixing. Checking for cracks or signs of corrosion in the oil cooler is essential, and replacing it with a new one is usually necessary to restore the system to normal operation.
   
2. Inspecting Engine Seals and Pumps
   If the oil cooler appears intact, the next step should be to check the engine seals, particularly those on the water pump and oil pump. If any seals are found to be damaged, replacing them is crucial to prevent further oil and coolant mixing.
   
3. Changing Oil and Coolant
   Once the oil cooler or seals are replaced, it’s important to change both the engine oil and coolant. This will clear out any contaminants that may have entered the systems and ensure that both the engine and cooling system are operating properly.
   

1. Issue Overview
On the Panswork forum, a user reported an issue with their 2007 CAT 262C skid-steer loader, where the bucket curl function does not hold its position. Specifically, after initially curling the bucket, it slowly uncurls and does not maintain the desired position. This issue can affect operational efficiency and safety, and it is important to diagnose and fix it promptly.
2. Common Causes

1. Hydraulic System Leaks
   • If there are leaks in the hydraulic system, hydraulic fluid will be lost, which can cause insufficient pressure to maintain the bucket's position. Leaks can occur in hydraulic hoses, connections, or seals.
     
2. Hydraulic Cylinder Seal Failure
   • The seals inside the hydraulic cylinders may wear out or become damaged over time, leading to hydraulic fluid leakage. This results in insufficient pressure to maintain the bucket’s position. Signs of seal failure include external oil residue on the cylinder or insufficient pressure inside the cylinder.
     
3. Hydraulic Pump or Control Valve Failure
   • The hydraulic pump is responsible for generating the pressure, while the control valve regulates the flow of hydraulic fluid. If either of these components malfunctions, it may fail to provide adequate pressure or flow, resulting in the bucket not holding its position or functioning as expected.
     
4. Poor Hydraulic Oil Quality
   • The quality of hydraulic oil is crucial to the performance of the hydraulic system. Using low-quality or contaminated hydraulic oil can cause the system to operate inefficiently, which can affect the bucket's control and stability.
     

1. Check for Hydraulic Leaks
   • First, inspect the entire hydraulic system for leaks, especially around hoses, fittings, and seals. Use a pressure gauge to check for leaks or drops in pressure. If a leak is found, replace the damaged parts immediately to restore proper pressure.
     
2. Inspect Hydraulic Cylinder Seals
   • Check the seals in the hydraulic cylinders, particularly the piston and rod seals, for signs of wear or damage. If the seals are compromised, they will need to be replaced to prevent hydraulic fluid leakage and restore pressure.
     
3. Check Hydraulic Pump and Control Valve
   • Ensure that the hydraulic pump is producing the correct pressure, and verify that the control valve is operating correctly. A faulty pump or valve can cause insufficient hydraulic flow, which will affect the bucket’s function. If either component is malfunctioning, repair or replace it.
     
4. Check Hydraulic Oil Quality
   • Inspect the hydraulic oil to ensure it is clean and meets the required specifications. If the oil is dirty, contaminated, or the level is low, drain and replace the oil with fresh, high-quality hydraulic fluid.
     

In a discussion on Panswork, a user shared their experience with a 2016 Bobcat T630 loader that is equipped with a Doosan engine. The user reported issues with the machine’s performance, particularly related to power loss and difficulty starting, which seemed to be linked to the Doosan engine. This raised concerns about the engine’s performance and maintenance, leading to a broader discussion about possible causes and solutions.
Engine Issue Description
The user described difficulties starting the machine, particularly during cold starts, where the engine took an unusually long time to start. Some users also mentioned that after the engine started, the machine experienced unstable operation, with insufficient power, difficulty accelerating, or maintaining speed. These issues appeared to be related to internal engine faults rather than external factors like fuel or battery issues.
Potential Causes of the Problem
Several users in the discussion suggested possible causes for these issues:

1. Fuel System Issues
   Some users pointed to potential problems with the fuel pump or injectors. If the injectors are clogged or malfunctioning, they may cause insufficient fuel supply, leading to starting issues and poor engine performance. A clogged fuel filter might also restrict fuel flow, affecting engine operation.
   
2. Air Intake System Problems
   A blocked air filter or leaks in the intake system could also reduce the airflow to the engine, affecting its performance. If the air filter is dirty or clogged, the engine may not receive enough air, leading to inefficient combustion and resulting in power loss.
   
3. Electrical System Problems
   Another potential cause discussed was an electrical issue, such as a weak or faulty starting battery or starter motor. If the battery voltage is insufficient or there is an issue with the electrical connections, the engine may struggle to start.
   
4. Internal Engine Issues
   Some users suggested that internal engine problems, such as worn piston rings, damaged cylinder heads, or faulty valves, could be causing low compression, making it difficult for the engine to start and perform at full power.
   

1. Fuel System Inspection: Ensure the fuel pump, injectors, and fuel filter are working properly to avoid fuel supply issues.
   
2. Air Intake System Inspection: Clean or replace the air filter and check for leaks or blockages in the intake system.
   
3. Electrical System Check: Ensure the battery is fully charged, and check the starter motor and electrical connections for any faults.
   
4. Internal Engine Inspection: If the issue persists, further inspection of the internal engine components, such as piston rings, cylinder heads, or valves, may be necessary.
   

1. Issue Overview
On the Panswork forum, a user reported fuel-related issues with their 2015 Bobcat T590 skid-steer loader. The user stated that the machine was having difficulty starting and running inconsistently, suspecting the problem was related to fuel supply or the fuel system. If fuel-related issues are not resolved promptly, they can prevent the engine from starting or reduce operational efficiency, affecting the equipment’s performance.
2. Common Causes

1. Clogged Fuel Filter
   • The fuel filter’s primary function is to filter impurities from the fuel and ensure that the fuel system stays clean. If the filter becomes clogged, it will limit the flow of fuel, which can prevent the engine from receiving enough fuel and lead to difficulty starting or poor operation.
     
2. Fuel Pump Failure
   • The fuel pump is responsible for delivering fuel from the tank to the engine. If the pump malfunctions or its efficiency drops, fuel flow will be insufficient, preventing the engine from starting or running properly. Damage to the pump is typically due to wear, corrosion, or blockages in the fuel lines.
     
3. Poor Fuel Quality or Low Fuel Level
   • Using poor-quality fuel or having insufficient fuel in the tank can also lead to inadequate fuel supply, affecting engine performance. Low-quality fuel may cause blockages in the fuel system, impacting fuel flow and engine operation.
     
4. Injector Issues
   • The fuel injectors are responsible for spraying fuel into the combustion chamber. If the injectors become clogged, worn, or malfunction, the fuel will not be atomized properly, leading to inefficient combustion, which can affect engine starting and performance.
     

1. Check the Fuel Filter
   • Inspect the fuel filter for any signs of clogging. If the filter is dirty or clogged, replace it with a new one to ensure the fuel can flow freely into the engine.
     
2. Check the Fuel Pump
   • Check the fuel pump to ensure it is working properly. If the pump is failing or not delivering the required fuel pressure and flow, it may need to be replaced.
     
3. Check Fuel Quality and Fuel Level
   • Make sure the fuel being used meets the required quality standards and that the fuel level is adequate. If there is any doubt about the fuel quality, drain the fuel tank and replace it with high-quality fuel.
     
4. Check the Injectors
   • Inspect the injectors for any signs of clogging or damage. Use injector cleaner to clean them if necessary. If the injectors are damaged or excessively worn, consider replacing them.
     

In a discussion on Panswork, users raised concerns about hydraulic pump hoses, particularly the challenges involved in selecting and replacing hoses. Hydraulic hoses are critical components in heavy equipment, and any damage or improper configuration can lead to system performance issues or failures. Therefore, understanding how to properly select and maintain hydraulic pump hoses has become a topic of interest for many operators.
Standards for Hose Selection
The selection of hydraulic pump hoses depends on several factors, including the working environment, the hydraulic system's pressure, flow requirements, and the hose's durability. Choosing the right hose ensures efficient system operation and extends the lifespan of the equipment. The following are key criteria for selecting hydraulic hoses:

1. Working Pressure and Flow
   The hydraulic hose must be able to withstand the maximum operating pressure and flow of the system. If the hose's pressure rating is lower than the system's requirements, it could lead to hose rupture or leaks. Therefore, it's crucial to understand the system's maximum pressure and flow requirements when selecting the hose.
   
2. Abrasion and Oil Resistance
   Hydraulic hoses are often exposed to harsh environmental conditions, making abrasion and oil resistance critical selection criteria. If the hose frequently rubs against the ground or other objects, abrasion resistance becomes especially important. Oil resistance ensures the hose can maintain a good seal over time and prevent leaks of hydraulic fluid.
   
3. Bend Radius
   The bend radius of the hydraulic hose must match the operational requirements of the equipment. If the hose’s bend radius is too small, it could impede fluid flow or even cause the hose to rupture. When selecting a hose, ensure it can bend smoothly within the machine's working environment while maintaining stable fluid transmission.
   

1. Hose Rupture
   Hose rupture is one of the most common issues due to high pressure or external friction in the working environment. To prevent this, users should regularly inspect the outer condition of the hose, especially in high-pressure areas and at connection points, looking for signs of wear or cracks.
   
2. Loose Connections or Leaks
   If the connection between the hose and the pump is loose or improperly sealed, oil leaks may occur, reducing system efficiency. This issue often requires regular tightening and inspection of the hose connections and ensuring that seals are intact and functioning properly.
   
3. Hose Aging
   Aging hoses are another common issue, particularly when exposed to UV light, heat, or chemicals over time. Aging hoses lose their elasticity, making them prone to rupture or sealing failure. Users should replace aged hoses regularly and avoid exposing them to harsh environments that accelerate deterioration.
   

1. Issue Overview
On the Panswork forum, a user reported issues with their Bobcat machine's hydraulic hammer. The user mentioned that the hydraulic hammer was working intermittently and its performance was affected. Since hydraulic hammers are commonly used in construction and demolition tasks, any performance issues can significantly impact efficiency and the lifespan of the equipment. Therefore, the user sought solutions for diagnosing and resolving the issue.
2. Common Causes of Failure

1. Insufficient Hydraulic System Pressure
   • The hydraulic hammer relies on the normal pressure of the hydraulic system to operate. If the hydraulic pressure is too low, the hammer may work sluggishly or fail to activate. Insufficient hydraulic fluid, a malfunctioning hydraulic pump, or issues with the pressure regulator can all contribute to this problem.
     
2. Poor Hydraulic Fluid Quality or Insufficient Fluid
   • Hydraulic fluid is critical to the operation of the hydraulic system, and the quality and quantity of the fluid directly affect the hammer's performance. If the hydraulic fluid is of poor quality or there isn't enough fluid, it can cause increased friction within the system, affecting the hammer's efficiency.
     
3. Internal Hammer Malfunctions
   • Problems within the hydraulic hammer itself, such as damaged valves, pistons, or seals, can also be the root cause. These components may wear out or get damaged over time due to prolonged use or inadequate maintenance, leading to operational issues with the hammer.
     
4. Loose or Worn Connection Parts
   • If the connection between the hydraulic hammer and the Bobcat machine is loose or the parts are worn, it may hinder hydraulic fluid transfer, impacting the hammer’s performance. This includes issues with hydraulic lines and fittings that may cause leakage or pressure instability.
     

1. Check the Hydraulic Oil System
   • First, check the hydraulic system’s oil level and pressure. Ensure that the hydraulic fluid is at the proper level and that the fluid quality meets the required standards. If the oil is dirty or degraded, replace it with fresh hydraulic fluid. Make sure the oil type is suitable and that the fluid is clean.
     
2. Inspect the Hydraulic Pump and Pressure Regulator
   • Check the hydraulic pump and pressure regulator to ensure they are functioning properly. If the hydraulic pump is faulty, it may need to be repaired or replaced. If the pressure regulator is malfunctioning, it may require adjustment or replacement.
     
3. Examine the Internal Components of the Hammer
   • If the hydraulic system appears to be functioning well but the hydraulic hammer is still experiencing issues, it is advisable to disassemble the hammer and inspect internal components such as the valve, piston, and seals. Look for signs of wear, damage, or jamming. Replace any damaged parts as needed.
     
4. Inspect the Connection Parts
   • Inspect the connections between the hydraulic hammer and the Bobcat machine. Ensure that all hydraulic lines and fittings are properly tightened and free of leaks. Use a torque wrench to ensure all connection points are secure.