I. LF3325 Fleetguard Oil Filter Core Structure
Fleetguard LF3325 Oil Filter for Heavy-duty Trucks/Generating Sets
The Fleetguard LF3325 is a full-flow spin-on oil filter, specifically designed for heavy-duty diesel engines by Fleetguard.
Its core structure is compact, and it is well-suited for harsh working conditions. Additionally, it consists of four key components that work together to ensure filtering effect and safety.
1. Spin-on Metal Housing of Fleetguard LF3325
The spin-on metal housing is made of high-strength cold-rolled steel and integrally stamped. Moreover, its surface has anti-rust and anti-corrosion treatment, which resists high temperature and pressure impact.
This design prevents filter deformation, damage or leakage; besides, it allows quick and easy installation and replacement.
2. Folded Composite Filter Paper
The folded composite filter paper mixes cellulose and glass fiber, processed by a special folding process. Furthermore, this process greatly increases the filtering area, with the Fleetguard LF3325’s filtration accuracy at 10–25μm.
It intercepts impurities efficiently while ensuring smooth oil circulation; additionally, it is durable for heavy-duty engine use.
3. Central Support Tube
The central support tube adopts a punched design with tough, strong material that effectively supports the filter paper. It prevents collapse under high oil pressure and ensures the filtering channel remains unobstructed.
In addition, it extends the LF3325 filter’s service life and enhances overall reliability.
4. Dual-Valve Protection Component
The dual-valve protection component includes a bypass valve and a check valve. The bypass valve’s preset opening pressure is 0.15–0.3MPa, made of corrosion-resistant metal and sensitive in response.
Meanwhile, the check valve uses silica gel or fluorine rubber, boasting strong sealing performance to prevent oil backflow when the engine stops.
The Fleetguard LF3325 is a full-flow spin-on oil filter. It is designed for heavy-duty diesel engines by Fleetguard.
Its core structure is compact, and it is suitable for harsh working conditions.
Additionally, it consists of four key components. These components work together to ensure filtering effect and safety.
1. Spin-on Metal Housing of Fleetguard LF3325
The spin-on metal housing is made of high-strength cold-rolled steel. It is integrally stamped and formed.
Moreover, its surface has anti-rust and anti-corrosion treatment. This design resists high temperature and pressure impact.
It prevents filter deformation, damage or leakage, and it is easy to install and replace quickly.
2. Folded Composite Filter Paper
LF3325 Oil Filter for All Fleetguard Heavy-duty Diesel Engines
The folded composite filter paper mixes cellulose and glass fiber materials. It is processed by a special folding process.
Furthermore, this process greatly increases the filtering area. The filtration accuracy of Fleetguard LF3325 is 10–25μm.
It intercepts impurities efficiently and also ensures smooth oil circulation. Besides, it is durable for heavy-duty engine use.
3. Central Support Tube
The central support tube adopts a punched design. Its material is tough and strong, which supports the filter paper effectively.
It prevents collapse under high oil pressure and ensures the filtering channel is always unobstructed.
In addition, it extends the LF3325 filter’s service life, enhancing the filter’s overall reliability.
4. Dual-Valve Protection Component
The dual-valve protection component includes a bypass valve and a check valve. The bypass valve’s preset opening pressure is 0.15–0.3MPa.
It uses corrosion-resistant metal material and responds sensitively when needed. Meanwhile, the check valve uses silica gel or fluorine rubber.
It has strong sealing performance, and it prevents oil backflow when the engine stops.
II. LF3325 Fleetguard Complete Working Process
1. Oil Inlet Stage
When the engine starts, the oil pump works quickly to draw and pressurize lubricating oil from the oil pan. Then, the pressurized oil enters the Fleetguard LF3325 filter through evenly distributed side inlets.
Subsequently, it flows smoothly into the annular chamber in a stable high-pressure state. This pressure provides sufficient filtration power and ensures full oil coverage on the filter paper surface; above all, this is the LF3325’s first working step.
2. Filtration Stage (Outside → Inside)
Under oil pressure, oil seeps slowly from outside to inside the filter paper. The filter paper’s micropores intercept impurities in grades, catching metal debris, carbon particles and colloids.
These solid impurities stay outside the filter paper, so they will not enter the subsequent oil circuit. Clean oil passes through the filter paper layer by layer, gathering into the central support tube; notably, the Fleetguard LF3325 ensures clean oil supply for the engine.
3. Oil Outlet & Lubrication Stage
Clean oil in the central tube is stably output through the filter’s bottom sealed outlet. After that, it enters the engine’s main lubricating oil circuit and is delivered to key moving parts like crankshaft bearings and camshafts.Fleetguard LF3325 Oil Filter Wholesale Price
It forms a dense wear-resistant oil film on part surfaces, reducing friction loss while cooling, sealing and cushioning; therefore, it ensures all engine parts work normally.
4. Emergency & Pressure Retention (Dual-Valve Protection)
The bypass valve mainly handles filter clogging or low temperatures. When the LF3325 filter clogs with impurities, resistance rises; when pressure exceeds 0.15–0.3MPa, the bypass valve opens automatically.
Unfiltered oil directly enters the main oil circuit, preventing serious engine failures like cylinder scuffing or bearing seizure due to oil shortage. On the other hand, the check valve retains pressure when the engine stops: once the engine shuts down, the oil pump stops, and system pressure drops instantly.
The check valve then closes quickly, sealing clean oil in the filter cavity to prevent backflow to the oil pan. It shortens cold start pressure build-up time, reduces dry wear during cold starts, and ultimately protects the Fleetguard LF3325 and engine safety effectively.
1. Oil Inlet Stage
When the engine starts, the oil pump works quickly. It draws lubricating oil from the oil pan and pressurizes it.
Then, the pressurized oil enters the Fleetguard LF3325 filter. It goes through the oil inlets evenly distributed on the filter side.
Subsequently, it enters the annular chamber smoothly. The oil is in a stable high-pressure state.
This pressure provides sufficient power for filtration and ensures oil covers the entire filter paper surface.
Above all, this is the first step of the LF3325 working process.
2. Filtration Stage (Outside → Inside)
Under oil pressure, oil seeps slowly from outside to inside the filter paper. The filter paper’s micropores intercept impurities in grades.
It catches metal debris, carbon particles and colloids. These solid impurities stay outside the filter paper.
As a result, they will not enter the subsequent oil circuit. Clean oil passes through the filter paper layer by layer.
It gathers into the central support tube. Notably, the Fleetguard LF3325 ensures clean oil supply for the engine.
3. Oil Outlet & Lubrication Stage LF3325 Fleetguard
Clean oil in the central tube is output stably. It goes through the sealed oil outlet at the bottom of the filter.
After that, it enters the engine’s main lubricating oil circuit. It is delivered to key engine moving parts.
These parts include crankshaft bearings and camshafts. It forms a dense wear-resistant oil film on part surfaces.
It reduces friction loss between parts and also cools, seals and cushions. Therefore, it ensures all engine parts work normally.
4. Emergency & Pressure Retention (Dual-Valve Protection)
The bypass valve mainly handles filter clogging or low temperature conditions. When the LF3325 filter is clogged with impurities, resistance rises.
When pressure exceeds 0.15–0.3MPa, the bypass valve opens automatically. Unfiltered oil enters the main oil circuit directly.
This prevents serious engine failures and avoids cylinder scuffing or bearing seizure due to oil shortage.
On the other hand, the check valve retains pressure when the engine is stopped. When the engine shuts down, the oil pump stops working.
System pressure drops instantly, so the check valve closes quickly.
Ultimately, it protects the Fleetguard LF3325 and engine safety effectively.
Fleetguard LF3325 Oil Filter for High-load Working Conditions
LF3325 Fleetguard CompatibilityandApplicability
This filter fits a wide range of heavy-duty engine models from global manufacturers. It is specifically compatible with models including AG CHEM EQUIPMENT 1004 (CUMMINS V504), KOMATSU PC400-6Z (KOMATSU SA6D125E-2A-C7), ALLIS-CHALMERS 260B, ALLIS-CHALMERS 945 (ALLIS-CHALMERS 25000 MKII), BOMAG MPH100 (DETROIT DIESEL 8V-71N), CHAMPION ROAD 100T (DETROIT DIESEL 16V-71), KOMATSU PC400-3 (KOMATSU S6D125-1), and KOMATSU PC450LC-6K (KOMATSU SAA6D125E-2C-8). Moreover, it complies with standard mounting dimensions for broad compatibility across multiple heavy equipment types.
LF3325 Fleetguard Oil Filter Specifications
Outer Diameter:118mm(4.65inch); Thread Size:1 1/2-12 UN; Length:286mm(11.26inch); Gasket OD:110mm(4.33inch); Gasket ID:98mm(3.86inch); Efficiency Beta 75 at 20 micron. Fleetguard LF3325 Oil Filter for Construction Machinery
https://kaixinfilter.com/product/lf9070-fleetguard-oil-filter/
https://kaixinfilter.com/product/lf9070-fleetguard-oil-filter/