Product Overview
The AF55015 is a heavy-duty cylindrical air filter element designed for Cummins QSB6.7, QSC, QSC9, and QSL9 industrial and marine diesel engines. Commonly found in construction equipment, marine vessels, generators, compressors, and agricultural machinery, these engines operate in some of the harshest environments on earth — from dusty construction sites to salt-spray marine applications. This filter provides the robust filtration and high airflow capacity these engines demand.
Key Features
Industrial-Grade Filtration: Engineered for continuous-duty applications — construction equipment, marine propulsion, generator sets, and compressor drives
Wide Cummins Compatibility: Fits QSB6.7 (6-cylinder), QSC (8.3L), QSC9, and QSL9 (8.9L) engine platforms across multiple equipment brands
Full Cross-Reference: Replaces AF55015, PA31000, 5261250, WA10715, AF2501, and 500715
Direct Flow 1200 Series: Part of the high-capacity Direct Flow filtration family with superior dust-holding capacity
Cylindrical Design: Radial seal configuration ensures positive sealing even under vibration and thermal cycling
Moisture-Resistant Media: Treated to resist moisture absorption in marine and high-humidity environments
Engine & Equipment Compatibility
Engine Platform
Displacement
Common Applications
Cummins QSB6.7
6.7L I6
Excavators, wheel loaders, forklifts, generators, marine
Cummins QSC / QSC9
8.3L I6
Bulldozers, graders, marine propulsion, industrial pumps
Cummins QSL9
8.9L I6
Cranes, drill rigs, agricultural tractors, generator sets
Specifications
Specification
Value
Part Number
AF55015
Cross References
PA31000, 5261250, WA10715, AF2501, 500715
Filter Type
Cylindrical / Radial Seal Air Filter
Series
Direct Flow 1200
Media Type
High-Capacity Cellulose with Moisture-Resistant Treatment
Seal Type
Radial Lip Seal (integrated)
Service Interval
500 hours (standard), 250 hours (severe dust)
Outer Diameter
Approx. 9 inches
Length
Approx. 14 inches
Why Proper Air Filtration Matters for Industrial Diesels
Industrial diesel engines ingest massive volumes of air — the QSB6.7 at full load consumes over 400 cubic feet of air per minute. Any dust or debris that bypasses the air filter becomes an abrasive inside the cylinders, accelerating piston ring, cylinder wall, and valve seat wear. In dusty environments common to construction and agriculture, a single hour of operation with a compromised filter can cause more engine wear than 100 hours with a clean filter. For marine applications, salt-laden air adds corrosion risk to the equation — making proper filtration doubly critical.
Installation Tips
Locate the air filter housing — typically a cylindrical metal or plastic canister near the engine intake
Release the housing cover latches or band clamp
Remove the cover and slide out the old filter element
Inspect the housing interior and clean any accumulated dust or debris
Check the safety element (inner filter) if equipped — replace if visibly dirty (sold separately)
Install the new AF55015 filter — ensure the radial seal seats evenly against the housing flange
Replace the cover and secure all latches/clamps — the filter must be held firmly in place
Reset the air filter restriction indicator if equipped (press the reset button on the indicator)
Frequently Asked Questions
Q: Does this fit my Bobcat with a Cummins QSB6.7?A: Many Bobcat models with the QSB6.7 use this filter, but always verify your specific machine's filter part number. Check your operator's manual or the part number on your existing filter before ordering.
Q: How often should I change this filter in marine use?A: For marine engines in saltwater environments, inspect every 250 hours and replace annually regardless of hours. Salt-laden air is more corrosive and can degrade filter media faster than inland air. Always check for signs of salt crystal formation on the filter element.
Q: What's the difference between the AF55015 and AF55020?A: The AF55015 is designed for the larger QSB6.7/QSC/QSL9 engine family, while the AF55020 fits the smaller QSF2.8/QSF3.8/QSB4.5 platforms. They are not interchangeable — the dimensions and airflow ratings differ significantly.
Q: Can I clean this filter with compressed air?A: Not recommended. Using compressed air can damage the filter media and create invisible tears that allow dust to pass through. This is a disposable filter — replace it when service is due. The cost of a new filter is negligible compared to the cost of premature engine wear.
Q: What happens if the air filter restriction indicator shows red?A: A red restriction indicator means the filter is clogged past the safe operating limit. Continued operation with a restricted filter causes excessive fuel consumption, power loss, increased exhaust smoke, and potential turbocharger damage. Replace the filter immediately and reset the indicator.
Related Products
AF55020 Air Filter for Cummins QSF/QSB Engines — Smaller engine platform filter
B085011 Primary Air Filter Round — Alternative industrial air filter
904-7904 Crankcase Breather for Cummins ISX — Engine breather filtration
Blog Resources
For industrial engine maintenance schedules, filter cross-reference guides, and equipment service tips, visit our Heavy Equipment Maintenance Blog.
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