HIMARKLIF Rubber Fuel Cap Gasket O-Ring for Peterbilt Trucks, 2PCS Nitrile Sealing Washers — OE-Sized, Oil-Resistant

HIMARKLIF Upgraded Rubber Fuel Cap Gasket O-Ring is a two-piece nitrile rubber sealing washer designed to restore a tight, leak-free fit between Peterbilt fuel tank caps and filler necks.

These replacement gaskets are molded from wear- and oil-resistant nitrile rubber with an increased thickness to match OE dimensions and improve sealing performance. Sold as a pair, each O-ring replaces worn or damaged seals on compatible Peterbilt diesel truck fuel caps, helping prevent fuel seepage and contamination while resisting corrosion and oxidation for extended service life.

Will this gasket stop fuel from leaking on my Peterbilt?

Yes — the gasket is sized to meet original-equipment standards and has a thicker cross-section than many aftermarket O-rings. Its nitrile composition is chosen for resistance to diesel and oil, which preserves the seal under normal operating conditions.

• OE-sized dimensions for a snug fit
• Upgraded thickness to close gaps between cap and port
• Nitrile rubber resists oil swelling and degradation
• Sells as a pair to replace both worn seals

Which Peterbilt models and part numbers does it replace?

This gasket fits many Peterbilt truck fuel tank caps and is compatible with a broad range of models listed by the manufacturer. It is intended as a replacement for the referenced part numbers so you can identify the correct swap easily.

• Compatible with models such as 320, 325, 330, 335, 337, 340 and others
• Also fits later model series: 357, 359, 362, 365, 367, 377, 378, 379
• Replaces part numbers: 562.1014, 572.1014.1, 572.1015
• Works for both older and many current Peterbilt diesel caps

How durable is the HIMARKLIF O-ring and what conditions can it withstand?

The gasket is made from high-quality nitrile rubber engineered for mechanical and chemical resistance. It withstands routine exposure to diesel fuel, oils, and the environmental factors encountered on the road while maintaining elasticity and shape.

• Wear- and oil-resistant nitrile compound
• Corrosion and oxidation resistance for longer life
• Flexible enough to maintain a seal despite vibration and temperature changes
• Sold as a 2-piece set to address common dual-cap applications

How do I install the replacement gasket and what should I check?

Installation is simple and requires no special tools: remove the fuel cap, take out the old O-ring, clean the sealing surface, then seat the new gasket into the cap bore before reassembling. Inspect the cap and filler neck for nicks or deformation that could prevent a proper seal.

• Remove cap and old gasket, clean mating surfaces
• Press new O-ring fully into the cap groove evenly
• Verify cap threads and filler neck are undamaged
• Test for leaks after reinstalling and refueling

Who is this for? The HIMARKLIF Upgraded Rubber Fuel Cap Gasket O-Ring is aimed at fleet managers, over-the-road drivers, and repair shops who need a reliable, cost-effective replacement seal for Peterbilt diesel fuel tank caps. It’s also suitable for owner-operators and maintenance technicians wanting an easy-to-install part that restores original-fit sealing, reduces fuel seepage risk, and extends cap service life without complex modifications.