Figure 3: Lip type
Leather Oil Seals - Leather Seals, also known as Type L Oil Seals, are most common in components that are subject to dirt and poor lubrication. Since they come pre-lubricated and are able to absorb fluids, leather oil seals are able to provide sealing properties in conditions that synthetic rubber is unable to.
Leather is probably the oldest of the lip materials still in common use, but the move towards mass production methods has seen a massive increase in the development of synthetic rubbers which lend themselves to accurate and repeatable injection and compression moulding. Nitrile (NBR) is still by far the most common elastomer for “normal” use, whilst Viton® (FKM/FPM) is rapidly replacing Polyacrylate (ACM) and Silicone (VMQ) for high-temperature applications. Viton® also has high resistance to abrasion and chemical attack making it a preferred elastomer. Recent developments in the use of PTFE for Rotary shaft seals has caused widespread interest particularly for high-speed shaft rotation or poor lubrication applications.
MH: O.D. wall is a rubber material
HM: O.D. wall is a metal case
MH(S)H: O.D. wall is metal with a reinforced inner metal case
O-rings are the most commonly used seals as they provide incredible value – very affordable, versatile, and efficient. They are made with several elastomer materials as to the application they will be used for, so it’s important that you know the materials an o-ring is made of before purchase.
Material used for Oil Seal :

Modern engine oils, such as the current SG classification for gasoline engines, contain a large fraction of additives, many of which are detrimental to fluoroelastomers. The primary functions of oil-additive packages are to protect metal parts, avoid deposits in the engine, minimize oil degradation, and adjust fluid viscosity. Little attention has been paid to avoiding damage to rubber seals. Instead, elastomer producers have been expected to provide new, higher-performing products at no increased cost to auto manufacturers. Among the additives with moieties that may attack fluoroelastomers at high temperature are detergents (phenolates), dispersants (succinimides, alkylphenol amines), and antioxidants (amines, sulfides, hindered phenols).4 Many of these components are multifunctional, containing phenol or amine groups that can dehydrofluorinate and crosslink VDF-containing fluoroelastomers, leading to loss of elongation and eventual embrittlement. However, the rate and extent of reactions with seals are affected by many factors, including whether air is present in the system. When oil is exposed to air at high temperature, additives may undergo considerable changes. For example, a significant fraction of amines may be oxidized to amides, which have little effect on fluoroelastomers.5
Another important factor to consider when choosing spark plugs for your MK7 GTI is the electrode material. The electrode material can vary between spark plugs and can have an impact on the performance of your engine. Copper, platinum, and iridium are common electrode materials used in spark plugs. Iridium spark plugs are often preferred for performance cars like the MK7 GTI due to their durability and ability to maintain a stable spark.
The 40mm rubber gasket is a versatile sealing solution that is commonly used in plumbing systems, automotive engines, hydraulic systems, and other machinery where a tight seal is required. Made from high-quality rubber materials, these gaskets are designed to withstand high temperatures, pressure, and chemicals, making them suitable for a wide range of applications.
Rubber valve cover gaskets offer several advantages, including flexibility, resilience, and resistance to heat and oil. These gaskets are designed to withstand the demanding conditions of automotive operation, providing reliable sealing solutions that contribute to the overall performance and safety of the vehicle. The use of high-quality rubber valve cover gaskets ensures effective sealing and protection of the engine components, contributing to the longevity and efficiency of the engine.
• Rubber torque prevents gear rattling noise
A valve cover gasket set typically includes all the necessary gaskets and seals required for the valve cover assembly. This comprehensive set ensures that all critical sealing components are replaced simultaneously, preventing potential leaks and ensuring the proper functioning of the engine. The inclusion of high-quality rubber valve cover gaskets in the set provides a reliable and complete sealing solution for the valve cover assembly.
As type A with dust lip