CAT Fuel Tank Vent AS 252-5805 For Tractor D10T 572R 613G 2525805

The Fuel Tank Vent (AS – Air Separation or Anti-Siphon) is a crucial component in Caterpillar tractors and heavy equipment, designed to manage airflow, prevent fuel starvation, and reduce the risk of fuel contamination or spillage. It ensures proper ventilation of the fuel tank while maintaining system integrity under various operating conditions.

Airflow Regulation: Allows air to enter the tank as fuel is consumed, preventing vacuum buildup that could restrict fuel flow.

Vapor Control: Helps release fuel vapors while minimizing emissions, often integrating with emissions control systems.

Anti-Siphon Protection: Prevents fuel theft or unintended siphoning due to external suction.

Contamination Prevention: Filters out dust, debris, and moisture from entering the fuel system.

Pressure Balance: Maintains optimal tank pressure to avoid fuel pump cavitation or tank deformation.

Vent Valve / Breather Cap: Allows air exchange while blocking contaminants.

Rollover Valve (ROV): Prevents fuel spillage in case of vehicle tilt or rollover.

Charcoal Canister (if equipped): Captures fuel vapors for emissions compliance.

Check Valve / Anti-Siphon Valve: Stops reverse fuel flow.

Hoses & Fittings: Connects the vent system to the tank and emissions control components.

Clogged Vent: Causes fuel starvation, engine stalling, or tank collapse.

Faulty Rollover Valve: May lead to fuel leaks or improper venting.

Damaged Hoses: Can introduce contaminants or cause venting failure.

Symptoms of Failure:

Difficulty refueling (slow fill or nozzle shutoff).

Engine power loss due to fuel starvation.

Fuel odor or visible leaks.

Agricultural & Construction Equipment (e.g., CAT D6, D7, 330 Excavator).

On-Highway Trucks (with emissions-compliant venting).

Off-Road Heavy Machinery (where dust and debris resistance is critical).