EE 821 Air Filter

EE-821 Heavy-Duty Engine Air Filter (Replaces 121-3661)

Ensure maximum engine protection and performance with the EE-821 Primary Air Filter. This standard-efficiency radial seal filter is engineered to meet the rigorous demands of industrial, construction, and agricultural machinery.

Designed as a direct replacement for the Caterpillar 121-3661, this filter effectively traps dust, dirt, and silica before they can reach your engine’s combustion chamber, preventing premature wear and costly downtime.

Key Performance Features:

• High-Efficiency Filtration: Multi-layered pleated media designed for high-dust environments.

• Radial Seal Technology: Features a durable urethane seal that ensures a leak-proof fit within the air cleaner housing.

• Rugged Outer Cage: Reinforced with a corrosion-resistant steel mesh to maintain structural integrity under high-intake pressure.

• Extended Service Intervals: High-capacity design allows for maximum dirt holding without sacrificing airflow.

Verified Compatibility & Cross-Reference

The EE-821 is a highly versatile filter used across a wide range of global manufacturers. We have verified the following cross-reference numbers:

Primary Equipment Applications

While primarily used in Caterpillar machinery, this filter is a standard fitment for numerous compact tractors, excavators, and forklifts:

• CAT Excavators: 301.5, 301.6, 301.8, 302.5, 303.5, 304, 305 series.

• CAT Compactors: CB214D, CB22, CB24, CB34 series.

• Kubota Tractors: L-Series (L2900, L3010, L3410), M-Series, and B-Series models.

• John Deere: Compact Utility Tractors and Commercial Mowers (790, 990, 3005, 4005).

• Forklifts: Various models from Toyota, Komatsu, and Mitsubishi using 4-cylinder diesel engines.

Technical Specifications

• Filter Type: Primary Engine Air Filter (Radial Seal)

• Outer Diameter: 105 mm (4.13 in)

• Inner Diameter: 63 mm (2.48 in)

• Height: 271 mm (10.67 in)

Pro Tip: This is the Primary (Outer) air filter. For maximum protection in extremely dusty conditions, it is often paired with a Secondary (Inner) safety filter. Check your equipment manual to see if you also require the secondary element during your next service.