HIMARKLIF Nitrile Fuel Cap O-Rings for Peterbilt Trucks – 2pcs OE-Size, Leak-Resistant Gaskets

HIMARKLIF's upgraded nitrile rubber fuel cap O-rings provide a durable, OE-size seal to stop fuel seepage on compatible Peterbilt truck fuel caps.

These two replacement gaskets are engineered to match original equipment dimensions while improving thickness and material resilience. Manufactured from high-quality Nitrile rubber, the set is built to resist oil, abrasion, oxidation and most common fuel contaminants, helping maintain a tight seal between the fuel cap and tank neck on a wide range of Peterbilt models. The package includes two washers designed to replace worn or damaged O-rings identified by part numbers 562.1014, 572.1014.1 and 572.1015.

How do these O-rings prevent fuel leakage on trucks?

The improved thickness and exact OE-style dimensions allow the HIMARKLIF gasket to fill gaps between the cap and tank opening, restoring a consistent contact surface. The nitrile compound resists swelling and degradation when exposed to diesel and fuel additives, maintaining compression set resistance under vibration and temperature changes.

• OE-matched diameter and upgraded thickness for reliable compression
• Nitrile rubber formulation resists oil and fuel-related breakdown
• Reduces seepage and prevents fuel smell in cab areas
• Helps maintain venting performance by preserving cap fit

Which Peterbilt models and part numbers are compatible?

This gasket set fits many Peterbilt truck fuel tank caps across classic and contemporary models. Refer to the list of model numbers and replacement references to confirm compatibility before installation.

• Compatible Peterbilt models include 320, 325, 330, 335, 337, 340, 348, 357, 359, 362, 365, 367, 377, 378, 379, 384, 385, 386, 387, 388, 389, 567, 579, 587
• Replaces OEM part numbers: 562.1014, 572.1014.1, 572.1015
• Sold as a 2-piece set to replace both worn gaskets or keep a spare

How durable are these gaskets under heavy use and harsh conditions?

The nitrile rubber composition is chosen for its resistance to oils, fuels and common environmental stressors, which extends service life compared with generic elastomers. Upgraded thickness and improved wear resistance reduce the chance of premature cracking or flattening under repeated cap cycles and road vibration.

• High wear and oil resistance extends replacement intervals
• Oxidation-resistant material minimizes hardening over time
• Thicker profile maintains sealing force despite repeated torqueing

What should I check when installing these replacement O-rings?

Proper installation ensures the gasket seals correctly and prevents future leakage. Inspect the fuel cap seating surface and tank neck for debris or damage, and replace the O-ring if it shows nicks, tears or permanent deformation.

• Clean the cap and tank flange before placing the new gasket
• Ensure the O-ring sits evenly without twisting or pinching
• Tighten the cap to the manufacturer's recommended engagement, not excessive force

Who is this for: HIMARKLIF's upgraded rubber fuel cap gaskets are for truck owners, fleet maintenance teams and technicians who operate Peterbilt trucks and need a reliable, OEM-dimension replacement to stop fuel seepage and restore proper cap fit. These gaskets suit anyone replacing aged or damaged seals on diesel fuel caps, performing preventative maintenance, or stocking common service parts for regional and long-haul fleets.