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.
This is one of the frequent reasons for oil seal failure, and this is majorly because of the volatility of any of the elastomer’s constituents. These causative constituents may be part of the elastomer formulation, or gases that got entrapped in the elastomer during the molding process. The deceiving fact about this failure is that sometimes the oil seal won’t show any visual sign of out-gassing, however, sometimes when the out-gassing is extreme, they shrink.
6. Ensure that the oil seal solidifies
Significance of Quality Seals in Automotive Applications:
Aspects to consider when selecting oil seals
Crankshaft front seal
Because of the higher temperature resistance of FKM, this material is also chosen for applications where higher speeds play a role, which raise the temperature at the sealing lip considerably. Usually, using FKM will result in a longer life than using NBR. This compensates the higher price of FKM compared to NBR, as an FKM does not have to be replaced as frequently. The low temperature resistance of standard FKM is limited to -15 ˚C.
Oil seals come in various shapes to fit the machines and substances to be sealed.
Figure 2 shows the structure and the names of the various components of the most typical oil seal.
The functions of the various components are also indicated in Table 1.
Generally, an oil seal is made up of an outer circular metal part and a bonded inner flexible material (often nitrile rubber) that does the actual sealing.
The pulley may slide off easily; if not, use a universal puller, which you may be able to hire.
The range of uses of peroxydically cross-linked EPDM includes in hot water and steam seals. EPDM is also very resistant to ageing and ozone. Compared with the usual types of synthesis natural rubber it has good resistance to cold temperatures. EPDM is not resistant to aliphatic or aromatic hydrocarbons or mineral oil products. Resistance to chemicals, and also to oxidising agents, is very good. Temperature range from -50 °C to +140 °C depending on type.
HALOGEN


Metal O.D. wall
(with a reinforcing inner metal case)
Oil seals are available in an immense range of sizes, for shafts from a few millimetres to several metres. Once the shaft diameter, groove diameter (housing diameter) and groove width are known, selecting an appropriate oil seal is a simple task. An oil seal or its product description is usually associated with three dimensions, for example 6x15x4. These refer to the sizes of the hardware for which the oil seal is designed. In this example, this oil seal is suitable for: 6-mm shaft diameter x 15-mm groove diameter x 4-mm minimum groove width.

oil valve cover gasket. It is important to ensure that the gasket is installed correctly and that the valve cover is tightened to the manufacturer's specifications to prevent leaks.
Double metal cased
8 Tips to Keep in Mind when Installing or Replacing Oil Seals

