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Bobcat’s Compact Excavator Legacy
Bobcat Company, founded in North Dakota in 1947, became a global leader in compact equipment through its pioneering skid-steer loaders. By the late 1990s and early 2000s, Bobcat expanded aggressively into the mini excavator market, offering machines tailored for tight urban spaces, landscaping, and utility trenching. The Bobcat 328G, introduced in the early 2000s, was part of this push—designed to deliver reliable performance in a compact footprint.
The 328G featured a rounded cab design, a hallmark of Bobcat’s early 2000s styling, and was powered by a Kubota D1703 diesel engine. With thousands of units sold across Europe and North America, the 328G became a staple for small contractors and rental fleets. Its reputation for mechanical simplicity and ease of transport made it a favorite in regions with narrow access roads and limited jobsite space.
Core Specifications and Mechanical Layout
The Bobcat 328G was engineered for versatility and maneuverability. Its zero-tail swing design allowed operators to work close to walls and obstacles without risking damage. The machine’s hydraulic system was designed to support digging, grading, and light demolition tasks.
Key specifications included:
• Engine: Kubota D1703, 3-cylinder diesel, ~27 hp
• Operating weight: Approximately 6,000 lbs
• Dig depth: Up to 9.5 feet
• Bucket breakout force: Around 4,200 lbs
• Hydraulic flow: ~11.5 GPM
• Track width: Adjustable between 59–70 inches
The machine used an open-center hydraulic system with gear-type pumps. Controls were mechanical, with pilot-assisted joysticks in later variants. The undercarriage featured rubber tracks and a dozer blade for backfilling and stability.
Terminology Clarification
• Open-center hydraulics: A system where hydraulic fluid flows continuously through the control valves until a function is activated.
• Pilot-assisted controls: Hydraulic controls that use low-pressure pilot fluid to actuate main valves, reducing operator effort.
• Breakout force: The maximum force the bucket can exert to penetrate or lift material.
Hydraulic Power Loss and Diagnostic Pathways
A common issue with aging 328G units is loss of hydraulic power after prolonged inactivity. In one case, a machine that had sat idle for several months exhibited weak or nonexistent hydraulic response, despite the pump appearing visually intact.
Initial checks should include:
• Relief Valve Pressure
The main relief valve regulates system pressure. If stuck open or misadjusted, it can bleed off pressure prematurely. On the 328G, this valve is typically located near the control valve block or pump outlet.
• Hydraulic Filter and Fluid Condition
Contaminated or degraded fluid can cause cavitation and reduce pump efficiency. Filters clogged with sludge or metal shavings restrict flow and pressure.
• Pump Coupling and Drive
Even if the pump looks new, a worn or broken coupling can prevent it from rotating under load. Check for slippage or misalignment.
• Electrical Solenoids and Safety Interlocks
Some functions may be disabled by faulty solenoids or seat switches. A multimeter test can confirm voltage at key control points.
• Air Entrapment
After long storage, air may enter the system. Bleeding the lines and cycling the controls can help restore full pressure.
Operator Anecdotes and Field Wisdom
In Romania, a new owner of a 2004 Bobcat 328G discovered hydraulic failure shortly after purchase. The pump had been removed and inspected, appearing “like new,” yet the machine lacked digging power. After consulting with experienced operators, the issue was traced to a misadjusted relief valve and possible air in the system. Once corrected, the machine regained full function.
In another case from Ontario, a landscaping crew revived a dormant 328G by flushing the hydraulic system with fresh fluid and replacing the filter. They noted that the machine’s compact size made it ideal for backyard trenching, but emphasized the importance of regular fluid changes—especially after long storage.
Maintenance Recommendations
To keep a Bobcat 328G in peak condition, consider the following:
• Change hydraulic fluid every 500 hours or annually
• Replace filters every 250 hours or when fluid is changed
• Inspect relief valve settings during major service intervals
• Grease all pivot points weekly, especially bucket and boom joints
• Check track tension monthly and adjust as needed
For machines stored long-term, drain fuel and hydraulic tanks, disconnect batteries, and cover exposed cylinders to prevent corrosion.
Modern Comparisons and Legacy
Compared to newer Bobcat models like the E26 or E32, the 328G lacks digital diagnostics, auto-idle, and emissions compliance. However, its mechanical simplicity and compact footprint make it ideal for restoration and use in low-tech environments.
Modern machines offer telematics, load-sensing hydraulics, and Tier 4 engines, but also require specialized tools and software for troubleshooting. The 328G, by contrast, can be serviced with basic tools and a good manual.
Conclusion
The Bobcat 328G remains a capable and reliable mini excavator, especially for operators who value mechanical honesty and field serviceability. Hydraulic issues, while frustrating, are often solvable with methodical diagnostics and a bit of patience. For those restoring or operating older compact equipment, the 328G offers a rewarding blend of performance, simplicity, and durability.
Bobcat Company, founded in North Dakota in 1947, became a global leader in compact equipment through its pioneering skid-steer loaders. By the late 1990s and early 2000s, Bobcat expanded aggressively into the mini excavator market, offering machines tailored for tight urban spaces, landscaping, and utility trenching. The Bobcat 328G, introduced in the early 2000s, was part of this push—designed to deliver reliable performance in a compact footprint.
The 328G featured a rounded cab design, a hallmark of Bobcat’s early 2000s styling, and was powered by a Kubota D1703 diesel engine. With thousands of units sold across Europe and North America, the 328G became a staple for small contractors and rental fleets. Its reputation for mechanical simplicity and ease of transport made it a favorite in regions with narrow access roads and limited jobsite space.
Core Specifications and Mechanical Layout
The Bobcat 328G was engineered for versatility and maneuverability. Its zero-tail swing design allowed operators to work close to walls and obstacles without risking damage. The machine’s hydraulic system was designed to support digging, grading, and light demolition tasks.
Key specifications included:
• Engine: Kubota D1703, 3-cylinder diesel, ~27 hp
• Operating weight: Approximately 6,000 lbs
• Dig depth: Up to 9.5 feet
• Bucket breakout force: Around 4,200 lbs
• Hydraulic flow: ~11.5 GPM
• Track width: Adjustable between 59–70 inches
The machine used an open-center hydraulic system with gear-type pumps. Controls were mechanical, with pilot-assisted joysticks in later variants. The undercarriage featured rubber tracks and a dozer blade for backfilling and stability.
Terminology Clarification
• Open-center hydraulics: A system where hydraulic fluid flows continuously through the control valves until a function is activated.
• Pilot-assisted controls: Hydraulic controls that use low-pressure pilot fluid to actuate main valves, reducing operator effort.
• Breakout force: The maximum force the bucket can exert to penetrate or lift material.
Hydraulic Power Loss and Diagnostic Pathways
A common issue with aging 328G units is loss of hydraulic power after prolonged inactivity. In one case, a machine that had sat idle for several months exhibited weak or nonexistent hydraulic response, despite the pump appearing visually intact.
Initial checks should include:
• Relief Valve Pressure
The main relief valve regulates system pressure. If stuck open or misadjusted, it can bleed off pressure prematurely. On the 328G, this valve is typically located near the control valve block or pump outlet.
• Hydraulic Filter and Fluid Condition
Contaminated or degraded fluid can cause cavitation and reduce pump efficiency. Filters clogged with sludge or metal shavings restrict flow and pressure.
• Pump Coupling and Drive
Even if the pump looks new, a worn or broken coupling can prevent it from rotating under load. Check for slippage or misalignment.
• Electrical Solenoids and Safety Interlocks
Some functions may be disabled by faulty solenoids or seat switches. A multimeter test can confirm voltage at key control points.
• Air Entrapment
After long storage, air may enter the system. Bleeding the lines and cycling the controls can help restore full pressure.
Operator Anecdotes and Field Wisdom
In Romania, a new owner of a 2004 Bobcat 328G discovered hydraulic failure shortly after purchase. The pump had been removed and inspected, appearing “like new,” yet the machine lacked digging power. After consulting with experienced operators, the issue was traced to a misadjusted relief valve and possible air in the system. Once corrected, the machine regained full function.
In another case from Ontario, a landscaping crew revived a dormant 328G by flushing the hydraulic system with fresh fluid and replacing the filter. They noted that the machine’s compact size made it ideal for backyard trenching, but emphasized the importance of regular fluid changes—especially after long storage.
Maintenance Recommendations
To keep a Bobcat 328G in peak condition, consider the following:
• Change hydraulic fluid every 500 hours or annually
• Replace filters every 250 hours or when fluid is changed
• Inspect relief valve settings during major service intervals
• Grease all pivot points weekly, especially bucket and boom joints
• Check track tension monthly and adjust as needed
For machines stored long-term, drain fuel and hydraulic tanks, disconnect batteries, and cover exposed cylinders to prevent corrosion.
Modern Comparisons and Legacy
Compared to newer Bobcat models like the E26 or E32, the 328G lacks digital diagnostics, auto-idle, and emissions compliance. However, its mechanical simplicity and compact footprint make it ideal for restoration and use in low-tech environments.
Modern machines offer telematics, load-sensing hydraulics, and Tier 4 engines, but also require specialized tools and software for troubleshooting. The 328G, by contrast, can be serviced with basic tools and a good manual.
Conclusion
The Bobcat 328G remains a capable and reliable mini excavator, especially for operators who value mechanical honesty and field serviceability. Hydraulic issues, while frustrating, are often solvable with methodical diagnostics and a bit of patience. For those restoring or operating older compact equipment, the 328G offers a rewarding blend of performance, simplicity, and durability.
