The KATO HD820R excavator has received significant attention in the construction industry due to its speed and efficiency. While users generally appreciate its performance, there are also some drawbacks. This review, shared by a user named Dai Rui Rui, provides insights after 3,636 hours of usage. Let's dive into his experiences with the machine.
Machine Overview
Purchased in May 2010 from Tianjin, the KATO HD820R was bought with a financing plan over three years at nearly 1.2 million RMB. All of the work done with this machine has been related to earthmoving tasks, and the owner, Dai Rui Rui, highlights the impressive speed at which the HD820R handles this type of work.
Engine and Fuel Efficiency
The HD820R is powered by a Mitsubishi 6D34 engine, which provides a rated power of 110 kW at 2,050 RPM. According to Dai Rui Rui, the fuel consumption of the excavator in general working mode is between 15 to 16 liters per hour. When operating at full load, the fuel consumption increases to around 22 to 25 liters per hour. This fuel efficiency is relatively good, considering the machine’s power and the type of work it performs.
Performance and Maintenance Issues
At around 3,000 hours of use, Dai Rui Rui encountered a minor issue with an oil seal leak on the guide wheel. Apart from this, there have been no other significant oil leaks, which is a point of satisfaction for him.
However, at 500 hours, the machine started emitting black smoke during operation. When the issue was raised with after-sales service, the response was that the problem stemmed from poor fuel quality and no maintenance measures were taken. This lack of support after the warranty period left Dai Rui Rui disappointed with the customer service.
Design and Aesthetic Feedback
On the design front, Dai Rui Rui finds the black engine cover of the HD820R particularly stylish. He also appreciates the convenient maintenance information stickers located on the machine, which outline the key maintenance areas and methods. However, he was let down by some issues related to the paintwork, which showed signs of peeling or chipping. This quality issue diminished his overall satisfaction with the machine's aesthetics.
Cabin and Comfort
In terms of operator comfort, the HD820R shines. The seat is highly adjustable, allowing for height adjustments and customizable spring tension to reduce vibrations, making it easier for the operator to work for long hours without discomfort. Additionally, the joystick control system is user-friendly and easy to operate.
However, Dai Rui Rui expressed some dissatisfaction with the display screen. The machine lacks a tachometer, and more importantly, there is no rearview camera, which can be a significant safety concern, especially when working in tight spaces or around obstacles.
Additional Modifications and Customizations
To further protect the machine, Dai Rui Rui added friction pads in areas prone to wear. He recommends this modification to new owners to prevent friction-related issues in the long term.
Summary of User Feedback
In conclusion, the KATO HD820R excavator has demonstrated excellent speed and work efficiency, particularly in earthmoving applications. Dai Rui Rui is generally satisfied with the machine’s fuel efficiency, comfort, and performance, though there are some areas that could use improvement:

• Fuel Efficiency: 15–16 L/h in regular mode, 22–25 L/h under full load.
  
• Minor Leaks: A guide wheel oil seal leak at 3,000 hours.
  
• Customer Service: Disappointing response from after-sales service, especially after the warranty expired.
  
• Aesthetic Quality: Issues with peeling paint.
  
• Comfort: Excellent seat comfort and easy-to-use joystick.
  
• Display: Lack of tachometer and rearview camera.
  
• Modifications: Useful friction pad additions to reduce wear and tear.
  

The Caterpillar 390D is the largest tracked excavator in the Caterpillar 300 series, and it has garnered significant attention in the construction machinery industry. Known for its robust performance, the 390D is recognized as a "giant" in the industry, both in terms of its size and capability. However, like any machine of its scale, it has faced rigorous scrutiny and feedback from users. While users are generally pleased with its performance, there are areas where improvements could enhance the overall experience.
User Background and Work Environment
Since its release, the Caterpillar 390D has attracted attention from users, particularly those in harsh working conditions such as coal mining. In one of the earliest user cases, six units of the 390D were deployed in Xinjiang, China. The primary task of these machines is to handle the removal of soil and coal from mining sites and load it onto transport vehicles. The work environment is particularly challenging, with extreme dust and heavy-duty operation conditions that test the machine's performance, durability, and operator control.
User Feedback and Performance
According to the first batch of users, the overall experience with the Caterpillar 390D is highly positive. Here are some key takeaways from their feedback:

1. Excellent Engine Performance: The engine delivers exceptional power and high efficiency, making it ideal for demanding jobs.
   
2. High Work Efficiency: The machine can complete between 9,000 and 13,000 cubic meters of work in 24 hours of continuous operation.
   
3. Effective Cooling System: The 390D is equipped with two large water tanks to help regulate the engine's temperature, ensuring continuous operation in high-stress environments.
   
4. Automatic Hydraulic Fan: The hydraulic fan is fully automatic, ensuring optimal cooling even in low temperatures when the machine starts.
   
5. Night Operation Support: Four batteries and eight lights are installed, ensuring sufficient lighting for nighttime work.
   
6. Comfortable Operator’s Cabin: The cabin features an airbag-style seat and comes standard with a radio for operator comfort during long hours of work.
   
7. Safe and Convenient Design: The machine has walkways on both sides for easy and safe access, enhancing operator safety.
   
8. Maintenance and Service: The machine has completed the first 500-hour service with relatively easy maintenance.
   
9. Fuel Consumption: Under full-load working conditions, the fuel consumption is approximately 80 liters per hour, which results in a daily fuel cost of around 10,000 RMB.
   
10. Minor Mechanical Issues: There have been occasional issues with bucket arm bolts breaking, but this was resolved by replacing the parts.
    
11. Optional Auto Greasing System: The automatic lubrication system is an optional feature, not standard, which adds to maintenance time if not chosen.
    
12. Bucket and Teeth Configuration: The machine comes with a 5.4 cubic meter bucket, but only four bucket teeth, which have a relatively wide spacing.
    
13. Balance Issues: Due to the shorter tracks, some users have reported a "tail swing" problem, affecting the machine’s balance.
    
14. Size and Maintenance Access: The machine is quite large, and maintenance cannot be performed on the ground without special equipment.
    
15. Camera Quality: The rear-view camera, while helpful, has low color saturation, which affects visibility.
    
16. Dust Issues: The working site is highly dusty, and the air filter needs to be cleaned every two days to ensure proper function.
    
17. Price: The price of each Caterpillar 390D unit is approximately 6 million RMB.
    
18. Manual: The user manual comes in English, which may require translation or a localized version for some users.
    

The Komatsu PC200-6E excavator, a model from the early 1990s, remains highly popular in the Chinese market, especially in the second-hand segment. Despite newer models being released, such as the PC200-8, the PC200-6E continues to stand out, particularly among users in Nigeria. The key reason for its popularity lies in the fact that many construction projects in Nigeria focus on earthwork, and the local labor rates are relatively low compared to other regions. As a result, users in Nigeria need machinery that provides high return on investment to adapt to the competitive environment, making the PC200-6E their go-to choice. Additionally, Guangzhou and Shenzhen are some of the busiest hubs for second-hand construction machinery, with many imported machines entering through Hong Kong and reaching Nigerian users, who are then able to access quality second-hand equipment.
A Well-Known Name Among Users
Purchasing one's first excavator can be a daunting decision, and reliable information often comes from word-of-mouth recommendations from friends and peers. In Nigeria, Japanese imported second-hand excavators are the most sought-after, and word-of-mouth is far more effective than heavy advertising. As a result, the reputation of the Komatsu PC200-6E has spread over the years, influencing new users entering the field. Mr. Zhan, a user who owns three Komatsu excavators, shares his personal experience with the PC200-6E. He started in 2008 with little knowledge of construction machinery, but after receiving recommendations from friends, he purchased the Komatsu PC200-6E. Over time, he found the machine reliable and was able to build his business on it.
User Experiences with the Komatsu PC200-6E
Durability, Low Maintenance Costs, and Fuel Efficiency
Mr. Zhan’s first PC200-6E had already accumulated around 5,000 hours when he purchased it, and now it has reached almost 10,000 hours of operation without any major repairs, only routine maintenance. This level of reliability has made him very satisfied with the machine, especially since he purchased the model with an intercooler, which further stabilized its performance. This durability is crucial in Nigeria, where labor costs are low, and an unreliable machine could result in significant losses due to downtime and repair costs. The PC200-6E's engine, the 6D95LE2, consumes only 11 to 12.5 liters of fuel per hour, making it highly fuel-efficient, which is especially beneficial for work on an hourly or daily basis.
Although no machine is completely free from issues, Mr. Zhan did experience minor failures in the generator and air conditioning system. However, the local repair shops in Nigeria are plentiful, skilled, and provide low-cost services, which helped him resolve the problems quickly and affordably. In his own words: “The fuel efficiency is excellent, and the machine rarely breaks down.”
Comfortable Operation
Though Mr. Zhan is not a professional operator, he occasionally uses the excavator and has developed an appreciation for its smooth and comfortable operation. He highlights that the PC200-6E's handling is particularly user-friendly compared to other brands, which can often feel clunky and unstable during operation. This positive feedback is consistent among many experienced operators, and it’s one of the reasons the PC200-6E remains so popular.
High Resale Value and Easy Marketability
After years of usage, an excavator will eventually be sold, and its resale value is a key factor. Thanks to the PC200-6E’s solid performance, demand for it remains strong in the second-hand market. In fact, some construction companies even request this specific model for their projects. When Mr. Zhan purchased his PC200-6E in 2008, it cost him around 550,000 yuan. Today, he estimates its resale value at around 400,000 to 650,000 yuan, depending on the market conditions. This high resale value shows just how well the machine holds its value, something that newer models can struggle to achieve after just a few years.
Tips for Maintaining the PC200-6E
While the PC200-6E is durable, regular maintenance is essential for long-term performance. Mr. Zhan emphasizes that operators should take good care of the machine, as it’s the key to maintaining its longevity and resale value. According to his experience, oil changes should be performed every 300 hours, and air filters and other consumables should be replaced regularly. He advises against cutting corners on these parts, either by finding trustworthy suppliers or opting for genuine parts.
When large components break, it’s better to repair them rather than replace them with cheaper, locally made parts. For example, Mr. Zhan had the generator repaired rather than replaced, and it continued to work fine afterward. He also mentions that the large arm occasionally experiences minor oil leakage, a common issue with this model. However, he suggests that if the leakage isn’t severe, operators shouldn’t rush to replace the seals, as the problem may resolve itself over time.
Final Thoughts
The Komatsu PC200-6E continues to be a strong performer in the second-hand market, particularly in Nigeria, where its durability, fuel efficiency, and comfortable operation make it the go-to choice for many users. Despite being an older model, it remains highly relevant and sought after, thanks to its reliable performance and strong resale value. For anyone considering a used excavator, the PC200-6E offers a proven track record that ensures both performance and profitability.

The SEM919 grader is a new product from Caterpillar SEM, retaining the design characteristics of Caterpillar graders. Compared to similar graders from other domestic brands, its appearance is similar, but it stands out in several areas with unique advantages and advanced features.
1. Key Configurations with Proven Technology from Reputable Brands

• Engine: The SEM919 is powered by the Shandong D9 turbocharged engine. This engine belongs to the D114 series, which has been under development since the mid-1980s. After more than 20 years of continuous improvement and innovation, it has become a mature and widely used engine in the construction machinery industry. It is compact, lightweight, durable, fuel-efficient, low noise, low emissions, and highly reliable, making it an excellent engine choice.
  
• Torque Converter and Transmission: The grader features the Hangzhou ZF WG180 torque converter and transmission system. It includes a torque converter and a multi-speed gearbox with an integrated transmission. This setup ensures smooth power delivery, minimal vibration, and stable operation. The transmission system is commonly used in domestic 180-horsepower graders, known for its low failure rate, high transmission efficiency, and ease of maintenance.
  
• Drive Axle: The drive axle is supplied by Xuzhou Meichi, which is known for its strong product development and innovation capabilities. The drive axles are durable, have a long lifespan, and can handle various working conditions. Meichi has established itself as an industry leader.
  
• Hydraulic System: The hydraulic system uses Rexroth load-sensing pumps, CAT directional control valves, and high-quality domestic components. This system is robust, long-lasting, and capable of handling various construction tasks.
  

SEM is set to launch two new motor graders, the SEM919 and SEM921, in the domestic market. In anticipation of the product release, SEM invited operators to experience these machines firsthand and provide valuable feedback to develop more targeted marketing strategies. To gain a deeper understanding of user impressions, SEM invited four experienced motor grader operators to participate in a test drive at their factory in Qingzhou, Shandong.
The test drive took place on July 22 in a spacious dirt field near the SEM factory, which provided an ideal terrain for various grader operations. After an in-depth introduction to the new products by SEM staff, operators began working with the SEM919 and another competing product currently available on the market.
According to SEM, both the SEM919 and SEM921 integrate Caterpillar’s proprietary technology, such as proportional priority and pressure-compensating control valves (PPPC). This technology makes the machines more responsive, improving overall performance and efficiency. The graders also feature world-class blade control systems, and the use of a control linkage pin and seven-hole connecting rods allows for fast and precise blade positioning. The optimized blade curvature and larger throat clearance improve material flow and passability, enhancing production efficiency. Furthermore, the new cooling system design ensures the machines can operate in extreme temperatures ranging from -40°C to 50°C.
The SEM919 and SEM921 are designed to offer three key features: fuel savings, ease of operation, and broad adaptability.
Test Drive Performance
During the test drive, operators put the SEM919 through various tasks including heavy load, light load, trenching, turning (to test maneuverability, turning radius, and efficiency), fly-cutting, and road grading. These tests evaluated the machine's handling capabilities. The machines' configuration, built with mature technology from well-known brands, earned high scores for control performance. Key configurations include:

• Engine: The SEM919 features a Shangchai D9 turbocharged engine, known for its compact size, lightweight design, long service life, good fuel economy, low noise, and high reliability.
  
• Hydrostatic Transmission: The SEM919 uses the Hangzhou ZF WG180 transmission, which combines a torque converter and a multi-gear power shift transmission. This system provides smooth transmission, low vibration, and minimal impact. Additionally, the rear-mounted hydrostatic transmission design saves space in the front and makes maintenance easier.
  
• Hydraulic System: The hydraulic system incorporates Rexroth load-sensing piston pumps, Caterpillar's directional control valves, and domestically recognized components. This robust system ensures long service life and supports various construction conditions.
  

As small-scale engineering projects continue to increase, there is a growing demand for compact and flexible machinery. Skid steer loaders, in particular, have gained popularity due to their small size and versatility. These machines are widely used in road maintenance, snow removal, landscaping, as well as in forestry, farming, and construction sites. BobCat, the global leader in skid steer loaders, recently launched its latest M Series model, the S770, in China. Compared to its predecessor, the S300, the S770 offers increased lifting capacity, greater lift height, and significantly improved hydraulic flow, delivering impressive power. The S770 belongs to BobCat's M Series, which was introduced in 2011 as the company's flagship lineup, representing the highest standard in skid steer loader technology today.
Exterior Design
The S300 belongs to BobCat's K Series, with "300" indicating the rated load capacity. In contrast, the S770 is part of BobCat's M Series, and its "770" refers to the model number within the series, marking a shift in naming conventions where the model numbers no longer reflect the load capacity.
The M Series has a more robust and commanding appearance. Notably, the S770 features a wider rear door panel and introduces a rear door locking mechanism, a standard feature across all M Series machines. The M Series also provides 30% greater visibility compared to the K Series, thanks to improved door design. Additionally, the M Series eliminates the front footstep found in the K Series by lowering the bottom edge of the door, making it easier to access the machine.
The "cat ears," the lighting system on BobCat skid steer loaders, also received a design update. The M Series offers a rounder shape compared to the K Series, featuring robust steel plate protection around the headlights. These new vacuum-sealed headlights provide 50% greater illumination, ensuring excellent visibility during nighttime operations.
Cab and Operator Comfort
The M Series represents a significant step forward in operator comfort and ergonomics. The S770’s cabin is far more luxurious compared to the S300, featuring standard adjustable suspension seats for comfort, 10 air conditioning vents to prevent temperature variations, and a 60% reduction in cabin noise levels compared to the K Series. The external noise is also reduced by 50%, ensuring a quieter working environment.
The S770 is equipped with a pressurized cabin, which prevents dust from entering the interior, a crucial feature when working in harsh environments such as cement plants or mining sites. All M Series machines, including the S770, come standard with this pressurized cabin.
Additionally, the M Series offers more storage compartments and a cup holder, addressing long-standing convenience issues. Legroom is more spacious than in the K Series, providing greater comfort for operators. As more younger workers enter the construction machinery industry, the demand for in-cabin entertainment has risen. In response, BobCat has designed the M Series to accommodate an optional audio system, allowing operators to enjoy music during long hours of work.
Internal Components and Hydraulic System
The M Series introduces several updates to key internal components, including the hydraulic quick-connect system. The hydraulic lines are now routed inside the lift arms, offering better protection for the quick-change mechanism. During the launch event, many attendees expressed interest in the air filter location, which has been relocated in the M Series to a more accessible position on top of the engine, replacing the previous round air filter with a square one. The M Series also adds a centrifugal filter, improving filtration efficiency by 30%.
The M Series also uses a three-point engine mounting system, compared to the K Series’ four-point system. This change results in reduced engine noise and improved stability. The radiator cleaning process has also been simplified; the M Series features a support rod fixation method for easier maintenance compared to the K Series' snap-on system.
Work Performance
Since its debut in 2011, the M Series has been synonymous with high-performance machinery. The S770 is a prime example, with a 15% increase in traction capacity and an 18% faster cycle time for dumping and turning. The S770 achieves a remarkable vertical lift height of 3.35 meters, supported by a hydraulic system with a flow rate of 23gpm and a high-flow rate of 36.5gpm, with a hydraulic pressure of 3500psi, providing substantial power for various tasks.
For example, the S850, another powerful model in the M Series, has an operating weight of 4540kg and a maximum lifting capacity of 1792kg. It also boasts a maximum lift height of 3.66 meters, making it ideal for a variety of tasks.
Each BobCat skid steer loader comes with numerous configuration options, including four control modes (Standard, Power Assist, Advanced Control System, and optional Joystick Control). Additional optional features include a deluxe dashboard, climate control, travel control, Bob-Tach attachment system, high-flow hydraulics, and a power management system.
Standard and Optional Features
Each BobCat skid steer loader comes with the following standard configurations:

• Bob-Tach attachment mounting system
  
• High-strength rear steel plates
  
• Reinforced lift arms
  
• Dual-channel cooling system
  
• Maintenance-free chain systems
  

• Model: S770
  
• Series: M Series
  
• Rated Load Capacity: 1520kg
  
• Tipping Load: 3039kg
  
• Max Lift Height: 3353mm
  
• Operating Weight: 4162kg
  
• Engine Power: 92hp
  
• Engine Type: Turbocharged Diesel
  
• Fuel Tank Capacity (dual fuel tanks): 124.3L (103.1L + 21.2L)
  
• Hydraulic System Pressure: 3500psi
  
• Hydraulic Flow Rate: 87.1L/min
  
• High Flow Rate (optional): 138.2L/min
  
• Travel Speed (Low): 11.4km/h
  
• Travel Speed (High): 19.8km/h
  

Kobelco excavators are renowned in the Japanese market for their fuel efficiency, earning them a reputation as the "Earthwork King" and "Shift King" among many users. These excavators have become the preferred choice for numerous construction professionals, especially those concerned with fuel consumption. However, while some enthusiasts view Kobelco machines as almost "legendary," their performance may not meet the high expectations of all users. The actual value of these excavators depends on the specific needs of the operator, and setting realistic expectations is crucial.
Advantages of Kobelco Excavators

1. Fuel Efficiency
   Compared to other brands like Caterpillar and Komatsu, Kobelco excavators stand out for their low fuel consumption. With rising fuel costs, Kobelco’s fuel efficiency becomes even more appreciated. For example, in earthmoving tasks, a 210-liter tank of diesel can last over 15 hours, and the fuel consumption rate on a six-speed setting is around 14-15 liters per hour. The fuel efficiency of Kobelco’s 200 and 210 models is impressive, particularly in smaller machines.
   
2. Speed and Productivity
   When it comes to earthmoving and loading tasks, Kobelco’s speed and fuel efficiency are hard to match. The 200 and 210 models, especially, offer an exceptional level of productivity. These machines provide a noticeable increase in speed and can perform significantly faster than their competitors, maximizing work output and profitability for the operator.
   
3. Reliability and Comfort
   Kobelco machines are known for their durable build. Despite their relatively low engine power, they are well-suited for earthmoving tasks. The operator cabins in Kobelco machines are spacious and comfortable, with ample room for additional personnel, making long hours more manageable. However, the seats tend to be harder, resembling those in older excavator models, which can be uncomfortable for some users.
   

1. Delicate Engine Performance
   Kobelco engines are somewhat delicate, meaning they are best suited for earthmoving tasks. The quality of the diesel used is crucial; poor-quality fuel can lead to significant engine wear. If the fuel filter is not regularly replaced with genuine parts, the machine's performance may degrade after about three years, leading to serious problems.
   
2. Complex Electrical System
   One common complaint among users is the complexity of the electrical system. As the machine ages, electrical components tend to malfunction, and repairs can be expensive and time-consuming. This issue is a notable weakness for Kobelco excavators, which is something prospective buyers should consider.
   
3. Lower Resale Value
   While Kobelco machines perform well, their resale value tends to be lower than that of American brands. The steel used in the construction of these machines is thinner compared to some competitors, affecting the machine's overall strength. Consequently, the resale market for Kobelco machines is not as strong, and they may depreciate faster than other brands.
   
4. Frequent Alarm System Alerts
   Kobelco's alarm system is designed to warn users of potential issues before they become serious problems. However, users often find that the alarms can be triggered frequently, sometimes even when there is only a minor issue. While this feature helps prevent major damage, it can be annoying and distracting for operators, especially when the alarms are triggered unnecessarily.
   

• Air Filters: The Super 8 includes an additional air filter.
  
• Water Separator: The Super 8 is equipped with an extra oil-water separator.
  
• Improved SCV Valve: The Super 8 features a revised SCV valve.
  
• Updated ECU System: The Super 8’s ECU system has been upgraded to enhance load handling.
  
• Engine Adjustments: In the Super 8, the engine operates more efficiently, with 100 fewer revolutions at idle and a higher top RPM compared to the SK-8.
  
• Side Air Inlets: The number of side air inlets has increased, improving ventilation and efficiency.
  
• Improved Excavation Bucket: The Super 8 models, such as the SK250 and SK260, have upgraded excavation buckets designed for deeper digging.
  

1. Kobelco SK75-8, 1300-Hour Usage Report
   A user shared their experience after 1300 hours of operation. The machine performed well in various tasks, including foundation leveling, trenching, and slope repair. The cabin is spacious, providing comfort even for two people. However, the seat was noted to be somewhat hard, and the inability to see the tracks from the cabin was a disadvantage during loading tasks.
   
2. Kobelco SK75-8, 1000-Hour Usage Report
   After 1000 hours of usage, this user was satisfied with the machine's performance. The cabin is large, with good noise insulation, and the machine is equipped with a powerful engine, delivering fast and efficient work. However, issues with the swing motor and muddy conditions that affected the machine's movement were mentioned. The cost of maintenance was also highlighted, with a total of 4935 yuan spent on 1000 hours of use.
   
3. Kobelco 210, 1600-Hour Usage Report
   After 1600 hours, the user reported that while the machine was effective and offered good value for money, the undercarriage quality could be improved. Despite its strengths, the user noted that the machine wasn’t as robust as Korean models, and its performance in cold weather could be better.
   

I purchased three Komatsu PC400-7 excavators, and after two months of use, the working hours have now reached around 2500 hours for each machine, with the initial hours being about 2000. The machine numbers are 5, 8, and 9, and I will provide an overview of the condition of these three excavators, offering insights for those interested in purchasing a 40-ton class excavator.
Excavator No. 5
This machine is mainly used for soil loosening operations, equipped with a ripper. The ripper was purchased for ¥9800. Initially, we used the bucket teeth from a LiuGong 225 excavator, but it was prone to breaking 5-6 teeth every day. It was considered a miracle if the teeth didn’t break within two days.
After multiple adjustments, we finally switched to Komatsu 400 (Diamond-branded) bucket teeth, which improved the situation. Since the PC400-7 is equipped with an electronic fuel injection engine, it had some issues when it arrived here, due to poor fuel quality at the previous job site. As a result, I had to replace the fuel injectors, which cost ¥13,500.
Excavator No. 8
This machine experienced an issue where the main belt broke within 100 hours of use. We then replaced the belts with a large one, incorporating two smaller belts, which cost ¥1300.
Excavator No. 9
This is the most stable of the three machines and the fastest in terms of operation. It is equipped with a 2.1 cubic meter bucket and has no trouble loading material. It can easily outpace the Doosan DH500 with a 3.2 cubic meter bucket.
Performance Comparison
In general, the Komatsu PC400 is significantly more powerful than the PC360. It is also nearly 10 tons heavier than the PC360, but the price is about ¥400,000 higher. Due to its long arm and deep bucket design, the PC400 is better suited for excavating weathered rock. The Doosan DH500, on the other hand, struggles when trying to cut into weathered rock with its oversized bucket, while the PC360’s wider bucket also has difficulty penetrating the material.
In terms of loading speed, the PC400 outperforms the PC360 by a wide margin, making it a much more efficient machine in this regard.
Fuel Consumption
The fuel consumption of the PC400 has been somewhat surprising. Currently, we operate the machine at full throttle:

• In Mode A (high power mode), the fuel consumption is around 50 liters.
  
• In Mode E (eco mode), the fuel consumption drops to about 40 liters.
  

1. No designated grease points
   Surprisingly, the PC400 does not have dedicated grease points, except for the open area in the rotating section.
   
2. Overweight transportation issues
   The weight of the domestic Komatsu PC400 is 38,500 kg, while the domestic PC400CSE weighs 42,000 kg, and the imported PC400 weighs 42,300 kg. This causes problems with overweight transportation, and even without overloading, we still face penalties. For example, when transporting across provinces, each fine can amount to ¥5000, which makes it risky to use highways.
   

I purchased the Sumitomo 200-3 excavator in early 2002, and it has now accumulated over 17,200 working hours. I’ve been the sole operator since it was new, so I believe I’m qualified to provide a detailed review of this machine.
Advantages of the Sumitomo 200-3
1. Speed
When this machine was new, its speed was exceptional—at least compared to any excavator I had operated before. Although I haven’t used the famous Kato model frequently mentioned in forums, I’ve seen it work, and I can confidently say that my Sumitomo 200-3 outperforms the Hyundai 215-7 in terms of speed (no offense to Hyundai 215 users, just my personal observation).
2. Reliability
This excavator has been quite reliable, with no unusual or obscure issues. Maintenance has been relatively straightforward:

• The small arm oil seals were replaced at around 9,000 hours.
  
• The bucket arm oil seals were replaced at over 10,000 hours.
  
• At 12,000+ hours, I had to replace the large arm seals. Two seals leaked within a week, which was likely due to natural wear.
  
• At over 13,000 hours, I replaced the hydraulic pump O-rings and the valve distribution repair kit.
  
• At over 15,000 hours, I replaced the track chain link segments.
  
• At 16,800+ hours, I had to overhaul the engine due to issues caused by the fuel pump. It had frequent stalling problems, which led to excessive oil burning. However, the engine didn’t have any visible leaks, and the overhaul was mostly a result of the fuel pump issues.
  

This Caterpillar 330D excavator arrived at the site on January 2, 2008, and has since accumulated 7928 hours of operation (I have mentioned this time before, and many people may not believe it, but I am reaffirming today that the hours are entirely accurate. As an operator, I don’t need to boast about my hard work; I’m here to have a sincere conversation with everyone). As the operator of this machine, I will share my experience regarding its faults and advantages.
Advantages Overview
Caterpillar, as a globally recognized brand in the construction machinery industry, has earned a stellar reputation, and its excavators are considered some of the best in the world. The Caterpillar 330D is no exception. It ranks among the top in global sales and also boasts an excellent resale value. Despite some minor issues, the overall performance is commendable.
Common Faults and Maintenance History

1. Oil Consumption:
   • From the time of delivery, this excavator has consumed oil at a relatively high rate, with approximately one bucket of oil consumed every 100 hours. It’s important to note that this is not a fault with the engine but rather a design feature by the manufacturer. All 330D models exhibit this behavior.
     
   • My recommendation is to change the oil every 1000 hours or even longer intervals. At this rate, 1000 hours would consume approximately 10 buckets of oil, which is equivalent to replacing the oil five times.
     
2. Oil Filter Replacement:
   • The oil filter should be replaced every 500 hours to ensure the engine remains in optimal condition.
     
3. Boom Cylinder Maintenance:
   • At 3000 hours, the oil seals of the boom cylinder were replaced, which was done free of charge by the manufacturer.
     
   • At 6000 hours, the boom cylinder cracked, and the cylinder body was replaced, costing approximately 4500 yuan.
     
4. Hydraulic Pump Replacement:
   • At 6500 hours, all six hydraulic pumps were replaced together, with each pump costing approximately 8000 yuan. This damage is primarily due to the poor quality of local oil.
     
5. Water Pump Replacement:
   • At 7000 hours, the water pump was replaced at a cost of around 10,000 yuan.
     
6. Other Issues:
   • Currently, there is slight oil leakage at the fan pump, but it has not yet been addressed.
     
   • The boom cylinder needs a new repair kit.
     
   • The fuel consumption is slightly high, but considering the amount of work performed, the overall cost remains reasonable.
     

1. Excavator Models:
   • There are two models of the Caterpillar 330D excavator in China, with the main difference being the length of the boom. The long boom is 50 cm longer than the short boom, with a bucket capacity of 1.67 cubic meters and 1.87 cubic meters, respectively. I operate the short-boom version.
     
2. Performance:
   • On the construction site, my Caterpillar 330D easily outperforms other 400-series excavators. Its control is extremely precise, and it responds quickly with ample power.
     
3. Cab Issues:
   • The cabin’s sealing isn’t perfect, and dust tends to get in. Additionally, there’s no radio installed in the cabin, which I had to install myself. These are minor drawbacks.