
305 valve cover gaskets. These gaskets are easy to install and can be done at home with the right tools and instructions.
• Quick response (centrifugal hydraulic pressure canceling mechanism) throughout the rotation range

There is a British Standard laid down for the control of synthetic rubbers. BS 3574 (1989) helps to determine shelf life – for instance, Nitrile (NBR) and Polyacrylic (ACM) are Group ‘B’ rubbers and have a 7-year life, whilst Silicone (VMQ) and Fluoroelastomers (Viton®) are Group ‘C’ rubbers and have a 10-year shelf life. PTFE and Leather do not come into this category but like the others should be kept in the original packing for as long as possible away from direct light, dust, and humidity. Ozone, which can also be produced by battery-driven forklift trucks has a very bad effect on synthetic rubbers. Finally, protect the sealing lip – DO NOT hang the seals on nails, wire etc.
Fluid Types - Various oil seals are able to withstand interactions with oils, fuels, grease, water and more. Knowing what type of fluid the rotary shaft seal will be in constant contact with will ensure the longevity of the seal and surrounding components.
Remove the cylinder head (See How to remove a cylinder head ), carefully peeling off the old gasket from the head or block. Make sure no dirt or carbon falls into the engine.
③ Lip type code
Before installing the oil seal, it is essential that the oil seal, shaft and bore are not damaged. So, ensure that the surfaces the oil seal comes in contact with do not have any sharp points or burrs. The sealing lip is fragile, so any minor damage to it can cause leakage. Also, make sure the oil seal is clean. Even a small amount of dirt can cause a leak. Therefore, never use a pre-used oil seal for the assembly.
Heat resistance
WHAT ARE THE TYPES OF OIL SEALS?
• High eccentricity-following lip shape
Choosing the wrong materials for an oil seal may result in premature wear, lip hardening, cracks, swelling, and subsequent expensive damage to the machinery in which the seal is used. It is therefore vital to gather all relevant data and consult with experts before purchasing to match the right type of oil seal with your application.

power steering oil seal.
There are a wide range of oil seals to select from for any number of uses, so this guide will break down the most common seals to help you choose the right one for whatever piece of machinery you are working on.
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