ID：1826282

• Brand: Volvo
  
• Model: EC250D
  
• Year of Manufacture: 2013
  
• Hours: 21,104 hours
  
• Location: Xuchang, Henan
  

• Brand: Volvo
  
• Model: EC250D
  
• Year of Manufacture: 2013
  
• Operating Hours: 21,104 hours
  
• Location: Xuchang, Henan, China
  

• Weight and Size:
  • Operating Weight: Between 24,600 to 28,000 kg
    
  • Bucket Capacity: Ranges from 0.48 m³ to 1.85 m³
    
  • Overall Transport Length: 10,260 mm
    
  • Transport Width: 2,990 mm
    
  • Cabin Height: 3,020 mm
    
• Engine and Power System:
  • Engine Model: D7E
    
  • Rated Power: 138 kW @ 1,800 rpm
    
  • Bore x Stroke: 108 mm x 130 mm
    
  • Maximum Torque: 870 Nm at 1,350 rpm
    
  • Engine Displacement: 7.1 L
    
  • Cylinders: 6
    
• Performance:
  • Swing Speed: 11.9 rpm
    
  • Bucket Digging Force: 152 kN
    
  • Arm Digging Force: 115 kN
    
  • Maximum Traction Force: 217 kN
    
  • Travel Speed: 3.5/5.5 km/h (low/high)
    
  • Swing Torque: 91.6 Nm
    

• Main Pump Maximum Flow Rate: 2 x 240 L/min
  
• Travel Hydraulic Pressure: 36.3 MPa
  
• Control Hydraulic Pressure: 3.9 MPa
  

• Fuel Tank: 470 L
  
• Hydraulic Oil Tank: 195 L
  
• Engine Oil Change Capacity: 32 L
  
• Coolant: 41 L
  
• Hydraulic System: 400 L
  

• Track Length: 4,450 mm
  
• Track Gauge: 2,390 mm
  
• Track Shoe Width: 600 mm
  
• Roller and Sprocket Details: 2 track rollers and 9 carrier rollers per side, with 49 track shoes per side
  

• Maximum Digging Radius: 10,260 mm
  
• Maximum Digging Depth: 6,980 mm
  
• Maximum Digging Height: 9,690 mm
  
• Maximum Dumping Height: 6,800 mm
  

1. Durability: Built to last, the Volvo EC250D has a strong and robust design, making it capable of handling tough conditions in construction, mining, and demolition tasks.
   
2. High Efficiency: The advanced hydraulic system and engine provide a powerful performance while keeping fuel consumption at an optimal level.
   
3. Comfort and Safety: The operator's cabin is spacious, comfortable, and designed for high visibility and low noise, improving both productivity and operator safety.
   
4. Versatility: With a range of different bucket sizes and arm configurations, the EC250D can be customized to suit various applications, making it highly versatile.
   

                               

ID：1826281

• Brand: Hitachi
  
• Model: ZX240-3G
  
• Year of Manufacture: 2013
  
• Operating Hours: 15,070 hours
  
• Storage Location: Henan - Xuchang City
  

                               

ID：1826280

• Brand: Volvo
  
• Model: EC360BLC
  
• Manufacture Year: 2012
  
• Operating Hours: 8888 hours
  
• Location: Henan - Xuchang City
  

• Brand: Volvo
  
• Model: EC360BLC
  
• Year: 2012
  
• Operating Hours: 8888 hours
  
• Location: Henan, Xuchang City
  

• Weight (kg): 36,900
  
• Bucket Capacity (m³): 1.35-3.0
  
• Arm Length (mm): 6450
  
• Boom Length (mm): 3200
  
• Engine Model: Volvo D12D
  
• Rated Power (kw/rpm): 198/1700
  
• Cooling Type: Water-cooled
  
• Displacement (L): 12.1
  

• Maximum Torque (N·m): 1475/1275
  
• Cylinder Configuration: 6
  
• Cooling System: Water-cooled
  
• Max Speed (km/h): 3.3/4.5 (low/high)
  
• Crawling Speed: 70% climbing ability (35°)
  

• Maximum Flow (L/min): 280×2 + 25.5
  
• Hydraulic Pressure (Mpa): 31.4/34.3
  
• Digging Force (kN):
  • Bucket: 215.0 (standard mode), 236.0 (boosted mode)
    
  • Arm: 161.0 (standard mode), 176.0 (boosted mode)
    

• Transport Length (mm): 11,070
  
• Transport Width (mm): 3,340
  
• Transport Height (mm): 3,350
  
• Ground Clearance (mm): 1210
  
• Minimum Ground Clearance (mm): 500
  
• Track Length (mm): 5,180
  
• Track Gauge (mm): 2,740
  
• Track Width (mm): 600
  

• Max Digging Radius (mm): 11,180
  
• Max Digging Depth (mm): 7,490
  
• Max Digging Height (mm): 10,320
  
• Max Dump Height (mm): 7,240
  
• Vertical Digging Depth (mm): 5,510
  
• Max Effective Digging Depth (mm): 7,320
  

• Fuel Tank Capacity (L): 620
  
• Hydraulic Tank Capacity (L): 220
  
• Engine Oil Change Capacity (L): 42
  
• Coolant Capacity (L): 60
  
• Hydraulic System Capacity (L): 500
  

                               

ID：1826278

• Brand: Kato
  
• Model: HD820R
  
• Year of Manufacture: 2016
  
• Operating Hours: 11,000 hours
  
• Location: Hunan - Hengyang City
  

• Brand: Kato
  
• Model: HD820R
  
• Year of Manufacture: 2016
  
• Operating Hours: 11,000 hours
  
• Location: Hunan - Hengyang City
  
• Price: $36,235
  
• Operating Weight: 19,800 kg (20 tons)
  
• Bucket Capacity: Standard 0.8 m³ / Reinforced 0.9 m³
  
• Arm Length: 5,630 mm
  
• Stick Length: 2,930 mm
  
• Country of Origin: Japan
  
• Power Type: Traditional Power
  
• Manufacturer: Joint venture / Imported
  
• Bucket Type: Backhoe
  

• Engine Model: Mitsubishi 6D34-TLC1B
  
• Rated Power: 110 kW @ 2,050 rpm
  
• Cooling System: Water-cooled
  
• Bore x Stroke: 104 mm x 115 mm
  
• Max Torque: 580 N·m @ 1,400 rpm
  
• Cylinders: 6
  
• Displacement: 5.86 L
  
• Operation Mode: Intercooler; Turbocharged engine; Direct Injection
  

• Swing Hydraulic Motor Type: Fixed Displacement Piston Motor
  
• Travel Hydraulic Motor Type: Variable Displacement Piston Motor, with reducers on both sides
  
• Main Pump Maximum Flow: 235 L/min x 2
  
• Travel Hydraulic Circuit: 32.9 MPa
  
• Main Pump Type: Variable Displacement Piston Pump x 2 + Gear Pump
  
• Work Hydraulic Oil Circuit: 31.4 MPa
  
• Bucket Cylinder (Qty × Bore × Stroke): 1 × 120 mm × 1,090 mm
  
• Stick Cylinder (Qty × Bore × Stroke): 1 × 135 mm × 1,630 mm
  
• Boom Cylinder (Qty × Bore × Stroke): 2 × 125 mm × 1,315 mm
  

• Ground Pressure: 44 kPa
  
• Swing Speed: 13 rpm
  
• Climbing Ability: 70% (35°)
  
• Bucket Digging Force: Standard 136 kN / High Power 144 kN
  
• Stick Digging Force: Standard 99 kN / High Power 104 kN
  
• Max Traction Force: 179.5 kN
  
• Travel Speed: 5.5 km/h (low) / 3.6 km/h (high)
  

• Fuel Tank: 320 L
  
• Hydraulic Oil Tank: 156 L
  
• Engine Oil Change Capacity: 22 L
  
• Coolant: 23 L
  
• Hydraulic System Capacity: 260 L
  

• Transport Length: 9,500 mm
  
• Transport Width: 2,820 mm
  
• Transport Height: 2,970 mm (to the top of the hoses)
  
• Cab Height: 2,860 mm
  
• Ground Clearance (Weight): 1,040 mm
  
• Minimum Ground Clearance: 4,650 mm
  
• Minimum Swing Radius: 3,460 mm
  
• Rear Swing Radius: 2,750 mm
  
• Track Length: 4,170 mm
  
• Track Gauge: 2,220 mm
  
• Track Plate Width: 600 mm / 700 mm / 800 mm
  
• Track Total Width: 2,820 mm / 2,920 mm / 3,020 mm
  
• Track Ground Length: 3,370 mm
  

• Max Digging Radius: 9,910 mm
  
• Max Digging Depth: 6,700 mm
  
• Max Digging Height: 9,760 mm
  
• Max Dumping Height: 6,830 mm
  
• Max Vertical Digging Depth: 6,120 mm
  

                                       

ID：1826277

• Brand: Shandong Lingong
  
• Model: E660FL
  
• Year of Manufacture: 2021
  
• Operating Hours: 4,100 hours
  
• Location: Hunan - Yiyang City
  

• Brand: Shandong Lingong
  
• Model: E660FL
  
• Year of Manufacture: 2021
  
• Operating Hours: 4,100 hours
  
• Location: Hunan - Yiyang City
  
• Price: $11,376
  
• Operating Weight: 6 tons (6,050 kg)
  
• Bucket Capacity: 0.21 m³
  
• Bucket Width: 795 mm
  
• Engine Type: Traditional power
  
• Manufacturer: Domestic (China)
  
• Bucket Type: Backhoe
  

• Engine Model: Yanmar 4TNV98-EXSLGC
  
• Rated Power: 38.3 kW @ 2200 rpm
  
• Cooling System: Water-cooled
  
• Bore x Stroke: 98 mm x 110 mm
  
• Max Torque: 191.8 N·m
  
• Displacement: 3.319 L
  
• Operation Mode: Four-stroke, direct injection
  

• Maximum Flow of Main Pump: 138 L/min
  

• Ground Pressure: 32 kPa
  
• Swing Speed: 11.5 rpm
  
• Bucket Digging Force: 45 kN
  
• Travel Speed: 2.4 km/h (low) / 4.8 km/h (high)
  

• Fuel Tank: 135 L
  
• Hydraulic Tank: 130 L
  
• Engine Oil Capacity: 11.6 L
  

• Transport Length: 5,930 mm
  
• Transport Width: 1,960 mm
  
• Transport Height: 2,620 mm
  
• Cab Height: 2,620 mm
  
• Ground Clearance: 740 mm
  
• Minimum Ground Clearance: 367 mm
  
• Minimum Swing Radius: 2,321 mm
  
• Track Length: 2,500 mm
  
• Track Gauge: 1,520 mm
  
• Track Width: 380 mm
  
• Track Ground Length: 1,950 mm
  
• Track Total Width: 1,960 mm
  

• Max Digging Radius: 5,990 mm
  
• Max Digging Depth: 3,846 mm
  
• Max Digging Height: 5,743 mm
  
• Max Dumping Height: 4,163 mm
  

                               

ID：1826271

• Brand: Komatsu
  
• Model: PC300-8
  
• Year of Manufacture: 2012
  
• Operating Hours: 16,600 hours
  
• Location: Fujian - Xiamen City
  
• Price: $37,640
  

• Brand: Komatsu
  
• Model: PC300-8
  
• Year of Manufacture: 2012
  
• Operating Hours: 16,600 hours
  
• Location: Fujian - Xiamen City
  
• Price: $37,640
  
• Operating Weight: 30 tons
  
• Engine Type: Traditional power
  
• Bucket Type: Backhoe
  

• Construction: Building roads, structures, and large earthworks.
  
• Mining: Excavating and hauling materials.
  
• Landscaping: Digging and clearing land for agricultural or recreational purposes.
  
• Utilities: Trenching for pipelines and cables.
  

Design Purpose
SANY divides its excavator lineup into U-series and C-series to meet different construction needs.

• U-series: Stands for Ultra-compact. These machines are designed for zero tail swing (ZTS) or short tail swing, making them ideal for confined spaces. Urban construction sites, indoor demolition projects, pipeline installations, and landscaping tasks all benefit from the flexibility of U-series machines. Their compact design allows operators to work close to walls or obstacles without risk of rear collisions.
  
• C-series: Stands for Conventional. These excavators feature a standard tail swing, with the rear of the upper structure extending beyond the track width. This design prioritizes stability and digging efficiency, making C-series machines more suitable for open construction sites, heavy earthmoving, stockpiling, and foundation work.
  

• U-series: Zero or minimal tail swing. The rear of the upper structure does not exceed the track width during rotation. This allows the machine to rotate 360° safely in narrow spaces and reduces the likelihood of accidental damage to surrounding structures.
  
• C-series: Standard tail swing. The rear overhang extends beyond the tracks, providing space for larger counterweights, which enhances stability, especially during high-intensity digging or lifting tasks.
  

• U-series: These machines are lighter and highly maneuverable, which is a significant advantage in tight spaces. However, due to the limited counterweight, they may have slightly lower stability compared to C-series machines when handling heavy loads or operating on uneven terrain.
  
• C-series: With a larger overall weight and greater counterweight, C-series excavators offer superior stability for long-duration or heavy-duty digging operations. This makes them more efficient for bulk earthmoving and construction tasks where space is not restricted.
  

• U-series: Best suited for confined urban environments, indoor or restricted-space operations, landscaping, and pipeline installation. These machines excel in areas where space is limited and precision is crucial.
  
• C-series: Optimal for open construction sites, large-scale earthmoving, site leveling, and stockpiling. Their larger size and stability make them ideal for heavy-duty projects and long working hours.
  

• U-series: Compact cabins provide excellent visibility, making it easier to operate near obstacles. Operators can perform precise digging or lifting tasks in tight quarters, and maneuvering is agile and responsive.
  
• C-series: Larger cabins offer improved comfort for long-duration work. Noise and vibration levels are better controlled, and operators benefit from a more spacious environment, which reduces fatigue during extended operations.
  

• U-series: Zero or short tail swing, compact, flexible, ideal for tight spaces, slightly lower stability under heavy loads.
  
• C-series: Standard tail swing, more stable, suitable for heavy-duty and open-area operations, higher lifting and digging efficiency.
  

Introduction to the Caterpillar E70B
The Caterpillar E70B is a compact, mid-sized tracked excavator that gained popularity in the late 1980s and early 1990s for its versatility and reliability in various construction and landscaping projects. Weighing approximately 15,260 pounds (6,920 kg) , it was powered by a 55.7 hp Isuzu AU-4LE2X turbocharged diesel engine . Its compact size allowed for maneuverability in confined spaces, making it suitable for urban construction and utility work.
Assessing the Condition and Repair Costs
When considering the restoration of a used E70B, it's crucial to evaluate its current condition. Common issues with older models include hydraulic system wear, undercarriage deterioration, and engine performance problems. Repair costs can vary significantly based on the extent of the damage and the availability of parts. For instance, overhauling the hydraulic pump or replacing the undercarriage components can be costly endeavors.
Market Value and Resale Potential
The resale value of a refurbished E70B depends on several factors:

• Age and Hours of Operation: Machines with lower operating hours and newer models fetch higher prices.
  
• Condition Post-Restoration: A well-maintained and refurbished machine can command a premium.
  
• Market Demand: In areas where compact excavators are in high demand, the resale value increases.
  

• Availability of Parts: Ensure that replacement parts are readily available and affordable.
  
• Skill and Time Investment: Assess whether you have the necessary skills and time to perform the restoration or if hiring professionals is more cost-effective.
  
• Long-Term Value: Evaluate if the restored machine will meet your operational needs and if its value justifies the investment.
  

The term "coal-fired dozer" evokes images of massive machines powered by steam or coal combustion, operating in the rugged terrains of early 20th-century mining sites. While modern dozers are powered by diesel engines, the evolution of these machines is deeply rooted in the industrial advancements of the past. This article delves into the history and development of coal-powered dozers, highlighting their significance in the mining industry and the technological innovations they spurred.
The Genesis of Coal-Powered Dozers
The origins of coal-powered dozers can be traced back to the early 1900s, a period marked by rapid industrialization and the burgeoning need for efficient mining equipment. During this era, steam engines were the primary source of power for heavy machinery. These engines, fueled by coal, provided the necessary force to operate large machines capable of moving vast amounts of earth.
One of the earliest examples of a coal-powered dozer was the "Track-Type Tractor" introduced by Benjamin Holt in 1904. Holt's innovation featured continuous tracks, offering superior traction and maneuverability, which proved invaluable in the challenging terrains of mining sites. This design laid the foundation for future developments in dozer technology.
Technological Advancements and Design Evolution
As mining operations expanded, so did the demand for more powerful and efficient dozers. The integration of steam engines into bulldozer designs marked a significant technological advancement. These steam-powered dozers were equipped with large coal-fired boilers that generated the necessary steam to drive the machinery. The introduction of steam engines allowed for greater power output and operational efficiency, enabling dozers to tackle more demanding tasks.
In the mid-20th century, the transition from steam to diesel engines began, driven by the need for more reliable and cost-effective power sources. Diesel engines offered higher fuel efficiency and reduced maintenance requirements compared to their steam counterparts. This shift marked a pivotal moment in the evolution of dozer technology, leading to the development of the modern diesel-powered dozers used in today's mining operations.
Legacy and Impact on Modern Mining Equipment
The innovations introduced by coal-powered dozers have had a lasting impact on the design and functionality of modern mining equipment. The principles of continuous tracks, powerful engines, and robust construction continue to be integral components of contemporary dozers. Moreover, the challenges faced and overcome during the era of coal-powered machinery have paved the way for advancements in automation, fuel efficiency, and environmental considerations in today's mining equipment.
Conclusion
The history of coal-fired dozers is a testament to the ingenuity and resilience of early industrial engineers. These machines not only revolutionized mining operations but also set the stage for the technological advancements that define modern dozers. While the era of coal-powered dozers has passed, their legacy endures in the machines that continue to shape the mining industry today.

The John Deere 510B backhoe loader, introduced in the early 1980s, is equipped with a 4-276D turbocharged diesel engine, renowned for its reliability and performance in construction and agricultural applications. However, some operators have reported issues with diesel fuel contaminating the engine oil, leading to concerns about engine health and performance.
Understanding the Issue
Diesel fuel mixing with engine oil is a serious concern as it can dilute the oil, reducing its lubricating properties and potentially causing increased wear or even engine failure. This contamination often results from fuel leaking into the oil system, which can occur through several pathways:

1. Injector Pump Front Seals: The injection pump, particularly models like the Roosa Master (also known as Stanadyne), can develop leaks in the front seals. These seals are responsible for containing the fuel within the pump. When they fail, fuel can seep into the engine oil. Operators have noted that this issue often manifests with erratic engine behavior, such as rough idling or misfires.
   
2. Fuel Return Line Blockages: The fuel return line from the injectors back to the tank can become clogged, causing fuel to back up into the injection pump. This pressure buildup can force fuel past the seals into the engine oil. Regular maintenance of this line is crucial to prevent such occurrences.
   
3. Injector Leaks: Faulty or worn injectors can leak fuel directly into the combustion chamber or into the oil system. This is often accompanied by visible smoke from the exhaust and a noticeable decrease in engine performance.
   
4. Excessive Idling: Prolonged idling can lead to incomplete combustion, allowing unburned fuel to wash down the cylinder walls and enter the crankcase. This not only dilutes the oil but can also lead to increased engine wear over time.
   

1. Inspect the Injection Pump: Check for signs of fuel leakage around the injection pump. If fuel is present, the front seals may be compromised. Testing the fuel return line for blockages can help identify if this is contributing to the issue.
   
2. Examine the Injectors: Remove and inspect the injectors for signs of wear or leakage. Testing their spray patterns can reveal if they are functioning correctly.
   
3. Monitor Engine Behavior: Pay attention to any changes in engine performance, such as rough idling, smoking, or loss of power, which can indicate fuel entering the oil system.
   
4. Check Oil Viscosity: If the oil appears thin or has a strong diesel odor, it may be contaminated. Changing the oil and filters can help mitigate immediate damage, but addressing the root cause is essential to prevent recurrence.
   

• Regular Maintenance: Adhere to a strict maintenance schedule for the injection system, including timely replacement of seals and filters.
  
• Proper Operation: Avoid prolonged idling and ensure the engine operates at optimal temperatures to promote complete combustion.
  
• Quality Fuel: Use clean, high-quality diesel fuel to minimize the risk of contaminants entering the fuel system.
  
• System Monitoring: Implement regular checks of the fuel return lines and injector systems to detect and address issues before they lead to contamination.