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

WMPARTS' aluminum fuel filter housing cap is a direct-fit replacement for part 134001 on 6.6L Duramax L5P diesel trucks, supplying a metal cap and high-temperature AEM O-ring to stop fuel seeps caused by cracked plastic caps.

Designed specifically for 2017–2026 Chevrolet Silverado 2500HD/3500HD and GMC Sierra 2500HD/3500HD equipped with the 6.6L Duramax L5P engine, this cap swaps in with basic hand tools in about 30 minutes. Manufactured using WMPARTS’ in-house tooling, the part prioritizes OEM-style alignment and tighter tolerances while replacing the factory plastic cap with a more durable aluminum body and a petroleum-resistant acrylic-rubber O-ring rated to 302°F (150°C). Note: the fuel filter element itself is not included.

How does this aluminum cap reduce fuel seeps on a Duramax L5P?

Plastic OEM caps can crack from repeated heat cycles and prolonged contact with diesel, creating hairline gaps that allow fuel to escape. The WMPARTS cap uses a corrosion-resistant aluminum housing that resists thermal stress and mechanical deformation, while the included AEM acrylic-rubber O-ring maintains a tight seal under high temperatures.

• Aluminum housing resists cracking from thermal cycling better than plastic.
• AEM acrylic-rubber O-ring rated to 302°F (150°C) for petroleum resistance.
• Precision tooling for OEM-like alignment reduces misfit-related leaks.

Will this cap fit my truck and how easy is it to install?

This cap is compatible only with 6.6L Duramax L5P diesel models from 2017 through 2026 in the specified Silverado and Sierra heavy-duty trucks. Installation is straightforward and intended to be a 30-minute job using common hand tools — no special modifications or adapters required.

• Fits 2017–2026 Chevrolet Silverado 2500HD/3500HD and GMC Sierra 2500HD/3500HD with 6.6L L5P only.
• Not compatible with 3.0L LM2, LZ0, or gasoline engines.
• Designed for a quick 30-minute install with basic tools.

What’s included and what else will I need?

The package contains the precision-machined aluminum housing cap and the AEM acrylic-rubber O-ring. The replacement is designed around the OEM TP1015 filter element specification, but the filter cartridge itself must be purchased separately.

• Included: aluminum fuel filter housing cap and AEM acrylic-rubber O-ring.
• Not included: TP1015-spec fuel filter element (sold separately).
• No additional modifications or parts required for proper fitment.

Is there support or warranty if I have fitment questions?

WMPARTS tests parts before shipping and backs this cap with a one-year quality assurance period. Their support team commits to responding to fitment or installation inquiries within 24 hours to help troubleshoot any concerns.

• 1-year quality assurance warranty included.
• Pre-shipment testing to reduce out-of-box issues.
• Support response typically within 24 hours.

Who is this for: this aluminum fuel filter housing cap is aimed at owners and technicians working on 2017–2026 Chevrolet Silverado 2500HD/3500HD and GMC Sierra 2500HD/3500HD trucks with the 6.6L Duramax L5P who want a longer-lasting replacement for the factory plastic cap. It’s particularly useful if you’ve experienced fuel seepage, are performing routine fuel-system maintenance, or prefer a metal component for improved durability and thermal stability. Ideal for DIY mechanics, shop technicians, and fleet maintenance teams seeking a direct-fit, precision-made alternative to the OEM plastic cap.