08-28-2025, 02:03 AM
Vermeer HG365 Grinder Overview
The Vermeer HG365 is a mid-sized horizontal grinder designed for land clearing, mulch production, and wood waste reduction. Built by Vermeer Corporation—founded in 1948 and headquartered in Pella, Iowa—the HG365 was part of a product line known for robust construction, modular hydraulic systems, and user-friendly controls. While not as widely distributed as the larger HG6000 or HG8000 models, the HG365 found a niche among contractors handling small to medium lot clearing projects. Its compact footprint and dual hydraulic pump system made it attractive for operations requiring mobility and versatility.
Symptoms of Hydraulic System Interruption
Operators have reported a recurring issue during heavy grinding loads: the infeed wheel stops turning, followed shortly by the belly conveyor and loadout conveyor. The engine does not stall or bog down significantly, but the turbocharger audibly spools up, indicating increased load. When the infeed is reversed, the loadout system resumes operation. This behavior suggests a hydraulic flow disruption rather than a mechanical or electrical fault.
Key symptoms include:
• Infeed wheel halts under heavy material load
• Belly and loadout conveyors stop shortly after
• Engine maintains RPM but turbo spools aggressively
• Reversing infeed temporarily restores conveyor function
• No low-pressure warning light triggered
Terminology Clarification
• Infeed Wheel: The hydraulic-driven roller that feeds material into the grinding chamber.
• Belly Conveyor: The horizontal conveyor beneath the grinding chamber that moves processed material toward the discharge.
• Loadout Conveyor: The final conveyor that transfers ground material to a pile or truck.
• Hydraulic Strainer: A mesh or screen filter that removes debris from hydraulic fluid before it enters the pump.
• Outflow Side: The return path of hydraulic fluid from the system back to the tank.
Hydraulic Architecture and Flow Dependencies
The HG365 uses separate hydraulic pumps for the infeed and loadout systems, meaning they should operate independently. However, both circuits share the same hydraulic tank and strainer. If the strainer becomes partially clogged, it can restrict fluid return or cause cavitation at the pump inlet. This would reduce available pressure and flow, especially under load, even if the pumps themselves are functioning correctly.
In this configuration:
• Infeed and loadout pumps draw from the same reservoir
• A clogged strainer affects both circuits simultaneously
• No low-pressure light may appear if the restriction is gradual or intermittent
Field Diagnosis and Recommended Actions
To address the issue:
• Remove and inspect the hydraulic strainer for debris, sludge, or metal shavings
• Clean or replace the strainer as needed
• Check fluid level and condition—dark or foamy fluid may indicate contamination or aeration
• Inspect return lines for kinks, collapsed hoses, or internal delamination
• Verify that the tank breather is clear and not creating vacuum pressure
• Monitor system pressure at both pump outlets during operation
If the strainer is clean and fluid condition is acceptable, consider testing pump output under load. A weak pump may pass bench tests but fail under dynamic conditions.
Operator Insight and Practical Experience
A contractor in British Columbia encountered similar symptoms on a different grinder model. After replacing the infeed pump and motor without improvement, he discovered that a collapsed return hose was restricting flow back to the tank. The hose appeared intact externally but had delaminated internally, creating a flap that blocked flow under pressure. Replacing the hose resolved the issue immediately.
Another operator in Georgia noted that his HG365 performed better in cooler weather. This suggests that fluid viscosity and thermal expansion may exacerbate marginal flow conditions. He installed a larger breather and added a secondary inline filter to reduce strain on the main strainer.
Preventive Measures and Long-Term Reliability
To maintain consistent hydraulic performance:
• Replace hydraulic fluid and filters every 500 hours or annually
• Inspect strainers and breathers quarterly
• Use high-quality fluid with anti-foaming additives
• Label and document hose replacement dates and pressure ratings
• Keep spare strainers and breather elements in the service kit
Conclusion
Hydraulic interruptions in the Vermeer HG365 during heavy grinding loads are often caused by shared flow restrictions, particularly at the strainer or return path. While the infeed and loadout systems are independently pumped, they rely on common fluid pathways that can become bottlenecks under stress. By inspecting and maintaining these shared components, operators can restore full functionality and avoid unnecessary component replacement. In hydraulic systems, the smallest restriction can create the biggest headache—and the HG365 is no exception.
The Vermeer HG365 is a mid-sized horizontal grinder designed for land clearing, mulch production, and wood waste reduction. Built by Vermeer Corporation—founded in 1948 and headquartered in Pella, Iowa—the HG365 was part of a product line known for robust construction, modular hydraulic systems, and user-friendly controls. While not as widely distributed as the larger HG6000 or HG8000 models, the HG365 found a niche among contractors handling small to medium lot clearing projects. Its compact footprint and dual hydraulic pump system made it attractive for operations requiring mobility and versatility.
Symptoms of Hydraulic System Interruption
Operators have reported a recurring issue during heavy grinding loads: the infeed wheel stops turning, followed shortly by the belly conveyor and loadout conveyor. The engine does not stall or bog down significantly, but the turbocharger audibly spools up, indicating increased load. When the infeed is reversed, the loadout system resumes operation. This behavior suggests a hydraulic flow disruption rather than a mechanical or electrical fault.
Key symptoms include:
• Infeed wheel halts under heavy material load
• Belly and loadout conveyors stop shortly after
• Engine maintains RPM but turbo spools aggressively
• Reversing infeed temporarily restores conveyor function
• No low-pressure warning light triggered
Terminology Clarification
• Infeed Wheel: The hydraulic-driven roller that feeds material into the grinding chamber.
• Belly Conveyor: The horizontal conveyor beneath the grinding chamber that moves processed material toward the discharge.
• Loadout Conveyor: The final conveyor that transfers ground material to a pile or truck.
• Hydraulic Strainer: A mesh or screen filter that removes debris from hydraulic fluid before it enters the pump.
• Outflow Side: The return path of hydraulic fluid from the system back to the tank.
Hydraulic Architecture and Flow Dependencies
The HG365 uses separate hydraulic pumps for the infeed and loadout systems, meaning they should operate independently. However, both circuits share the same hydraulic tank and strainer. If the strainer becomes partially clogged, it can restrict fluid return or cause cavitation at the pump inlet. This would reduce available pressure and flow, especially under load, even if the pumps themselves are functioning correctly.
In this configuration:
• Infeed and loadout pumps draw from the same reservoir
• A clogged strainer affects both circuits simultaneously
• No low-pressure light may appear if the restriction is gradual or intermittent
Field Diagnosis and Recommended Actions
To address the issue:
• Remove and inspect the hydraulic strainer for debris, sludge, or metal shavings
• Clean or replace the strainer as needed
• Check fluid level and condition—dark or foamy fluid may indicate contamination or aeration
• Inspect return lines for kinks, collapsed hoses, or internal delamination
• Verify that the tank breather is clear and not creating vacuum pressure
• Monitor system pressure at both pump outlets during operation
If the strainer is clean and fluid condition is acceptable, consider testing pump output under load. A weak pump may pass bench tests but fail under dynamic conditions.
Operator Insight and Practical Experience
A contractor in British Columbia encountered similar symptoms on a different grinder model. After replacing the infeed pump and motor without improvement, he discovered that a collapsed return hose was restricting flow back to the tank. The hose appeared intact externally but had delaminated internally, creating a flap that blocked flow under pressure. Replacing the hose resolved the issue immediately.
Another operator in Georgia noted that his HG365 performed better in cooler weather. This suggests that fluid viscosity and thermal expansion may exacerbate marginal flow conditions. He installed a larger breather and added a secondary inline filter to reduce strain on the main strainer.
Preventive Measures and Long-Term Reliability
To maintain consistent hydraulic performance:
• Replace hydraulic fluid and filters every 500 hours or annually
• Inspect strainers and breathers quarterly
• Use high-quality fluid with anti-foaming additives
• Label and document hose replacement dates and pressure ratings
• Keep spare strainers and breather elements in the service kit
Conclusion
Hydraulic interruptions in the Vermeer HG365 during heavy grinding loads are often caused by shared flow restrictions, particularly at the strainer or return path. While the infeed and loadout systems are independently pumped, they rely on common fluid pathways that can become bottlenecks under stress. By inspecting and maintaining these shared components, operators can restore full functionality and avoid unnecessary component replacement. In hydraulic systems, the smallest restriction can create the biggest headache—and the HG365 is no exception.
