WMPARTS Aluminium Fuel Filter Housing Cap for 6.6L Duramax L5P (2017–2026) with High‑Temp AEM O‑Ring

WMPARTS' aluminum fuel filter housing cap replaces GM part 134001 for 2017–2026 6.6L Duramax L5P diesel trucks, providing a durable, OEM-fit metal cap plus a high-temperature AEM O-ring.

Owners of Chevrolet Silverado 2500HD/3500HD and GMC Sierra 2500HD/3500HD with the 6.6L Duramax L5P often face fuel seep issues from the stock plastic housing cap. This WMPARTS replacement uses precision in-house tooling and an aluminum construction to resist heat and fuel exposure, while the supplied AEM acrylic-rubber O-ring is rated to 302°F (150°C) for improved sealing in diesel environments. The cap is designed for straightforward installation, matches OEM alignment, and is sold with the cap and O-ring only — the filter element is not included.

How does this aluminum cap reduce fuel seeps compared with the original plastic cap?

Aluminum is far less susceptible to the cracking and deformation that can occur in plastic under repeated thermal cycles and diesel contact. By replacing the original plastic cap with a metal version, the sealing surface stays stable and the AEM O-ring keeps consistent compression to prevent leaks.

• Aluminum body resists heat and fuel-related degradation.
• AEM acrylic-rubber O-ring rated to 302°F / 150°C for petroleum resistance.
• Precision tooling ensures consistent sealing faces and alignment.

Will this cap fit my truck and how easy is installation?

This cap is engineered specifically for 6.6L Duramax L5P diesel engines in 2017–2026 Silverado and Sierra 2500HD/3500HD models. It installs using common hand tools and is intended to be a quick swap with no permanent modifications.

• Compatible only with 6.6L Duramax L5P diesel (2017–2026) vehicles.
• Not compatible with 3.0L LM2, LZ0, or gasoline engines.
• Designed for a 30-minute installation using basic hand tools.

What exactly comes in the box and what else will I need?

The package contains the precision-machined aluminum housing cap and the AEM acrylic-rubber O-ring. The fuel filter element itself is not included, and the cap accepts the OEM-spec TP1015 filter element if you need to replace the filter.

• Included: aluminum housing cap and AEM-rated O-ring.
• Not included: fuel filter element (TP1015 compatible).
• No special adapters or permanent modifications required.

What warranty and support does WMPARTS provide?

WMPARTS tests every product before shipment and backs this cap with a one-year quality assurance warranty. Their support team is available to answer fitment and installation questions, typically responding within 24 hours.

• 1-year quality assurance warranty included.
• Pre-shipment testing to ensure fit and finish.
• Customer support with a usual 24-hour response window.

Who this product is for: This aluminum fuel filter housing cap is suited to Duramax L5P diesel truck owners and technicians who want a longer-lasting, fuel-resistant replacement for the OEM plastic cap. Choose it if you own a 2017–2026 Chevrolet Silverado 2500HD/3500HD or GMC Sierra 2500HD/3500HD with the 6.6L Duramax L5P and you want a direct-fit, durable cap and high-temperature O-ring for improved sealing without modifying the fuel system.