The Alltrux ATX21685 T-Chain Style Fuel Cap replaces OEM 20770657 and is designed as a direct replacement for Peterbilt heavy-duty truck fuel tank applications. Featuring a tethered T-chain design, this cap helps prevent loss during fueling while maintaining a secure seal that protects the fuel system from contamination and vapor leakage.

Fuel caps are critical components for maintaining fuel tank integrity by preventing dirt, moisture, and debris from entering the fuel supply. A properly sealing cap helps preserve fuel quality, supports consistent engine performance, and reduces the risk of contamination-related fuel system issues in demanding commercial trucking environments.

Engineered for durability in fleet and vocational applications, this tethered fuel cap provides dependable sealing and convenience for drivers and maintenance personnel who require reliable, easy-to-use fuel tank hardware. Always verify filler neck size and application compatibility prior to installation to ensure proper fitment.

Key Features

Direct replacement for OEM 20770657
Alltrux Part Number: ATX21685
T-chain tethered design to prevent cap loss during fueling
Helps protect fuel system from contamination and debris
Provides secure sealing for heavy-duty truck fuel tanks
Designed for Peterbilt and similar heavy-duty truck applications

Technical Specifications

Brand: Alltrux
Part Number: ATX21685
OEM Cross Reference: 20770657
Product Type: Fuel Cap (T-Chain Style)
System: Fuel System
Condition: New Aftermarket
Application: Heavy-Duty Truck Fuel Tanks (Peterbilt-style applications)

Cross References

OEM: 20770657
ALLTRUX: ATX21685