Place the ruler or straight-edge on edge diagonally across the head and block and look for gaps showing light anywhere between the ruler and block.


Oil seal type or shape


2. Metal Case
These seals are more commonly used in pumps, motors both electric & hydraulic, gearboxes & occasionally dirt wipers in hydraulic cylinders. They help protect shafts and bearings from dirt and harmful contaminants entering the internals of the application that they are fitted to, as well as prevent any leaks of lubricant.