8mm Oil Pump Cover Sealing Nut

OVERVIEW

In the world of air-cooled Volkswagens, chasing down oil leaks can feel like a never-ending battle, but the 8mm Oil Pump Cover Sealing Nut is one of the most effective weapons in your arsenal. Designed specifically for the high-pressure environment of the oil pump, this specialized fastener features an integrated sealing insert that prevents oil from migrating through the threads of the pump studs. Standard nuts often allow oil to seep out, leading to a messy engine case and potential oil pressure loss over time. By utilizing the 111-115-161 sealing nut, you ensure that the oil stays exactly where it belongsinside the pump and flowing through your engine galleries. Whether you are performing a routine oil change or a complete engine overhaul, these nuts are a non-negotiable requirement for a professional-grade, leak-free finish that stands up to the heat and vibration of a flat-four powerplant.

Precision is everything when it comes to the lubrication system of your VW Beetle, Bus, or Ghia. These 8mm sealing nuts are manufactured to meet or exceed original factory specifications, providing the perfect clamping force for your oil pump cover plate while simultaneously creating a vacuum-tight seal. Because the oil pump is the heart of your engine, any air leak on the suction side or fluid leak on the pressure side can lead to catastrophic failure. Using these self-sealing nuts eliminates the need for messy RTV silicone or outdated thread sealants that can break off and clog your oil passages. At Appletree Automotive, we understand that a dry engine is a happy engine, and these nuts are the small but mighty components that make the difference between a garage floor covered in oil spots and a pristine, high-performance machine ready for the open road.

FITMENT

This 8mm Sealing Nut is designed for VW engines equipped with 8mm oil pump studs, typically found on later model engines or performance cases. Please verify your stud size before ordering.

• VW Beetle: 1971 - 1977 (Standard and Super Beetle)
• VW Karmann Ghia: 1971 - 1974
• VW Bus / Type 2: 1971 - 1979 (Including 1600cc and Type 4 engines)
• VW Type 3 (Squareback, Fastback, Notchback): 1971 - 1973
• VW Thing: 1973 - 1974
• VW Type 4: 1971 - 1974
• Custom Engines: Fits all AS41 and AS21 dual-relief cases tapped for 8mm oil pump studs.

SPECS

• Thread Size: M8 x 1.25 Metric
• Nut Style: Hex Head with Integrated Sealing Insert
• Part Number Reference: 111-115-161 / 111115161
• Material: High-Strength Grade Steel
• Finish: Zinc Plated for Corrosion Resistance
• Quantity: Sold Individually (Note: Most oil pump covers require 4 per installation)
• Application: Oil Pump Cover Plate Fastening

PRO TIPS

1. Always Treat These as One-Time Use Components

The integrated sealing material inside the 111-115-161 nut is designed to deform and create a custom seal against the threads and the face of the oil pump cover upon its first installation. Once it has been torqued down and subjected to engine heat cycles, that sealing material loses its elasticity and its ability to provide a 100% leak-proof barrier. While the nut may still hold tension if reused, the risk of oil weeping through the threads increases significantly. To maintain a truly dry engine, you should always install a fresh set of four sealing nuts every single time you remove the oil pump cover for inspection or pump replacement. It is a small investment that prevents a major headache down the line.

2. Proper Torque is Critical for a Uniform Seal

When installing your oil pump cover, it is vital to use a calibrated torque wrench and follow a cross-pattern sequence. Over-tightening these nuts won''t make them seal better; in fact, it can warp the oil pump cover plate or pull the studs out of the magnesium or aluminum engine case. For most 8mm stud applications, the factory recommends a torque setting of approximately 14 ft-lbs (20 Nm). By tightening the nuts in a star pattern, you ensure that the cover plate exerts even pressure against the pump body and the gasket, which allows the sealing nuts to perform their job perfectly without distorting the pump''s internal tolerances.

3. Clean the Studs and Cover Surface Thoroughly

Before threading on your new sealing nuts, take the time to clean the oil pump studs and the cover plate surface with a high-quality brake cleaner or solvent. Any residual old oil, grit, or bits of old sealant on the threads can interfere with the nut''s ability to spin on smoothly and can compromise the integrity of the sealing insert. Check the studs for any nicks or burrs that might tear the sealing material as you install the nut. A clean, smooth thread ensures that the torque reading is accurate and that the seal is formed against metal, not against grime, resulting in a professional-grade seal that will last for years of driving.