Take a clean sheet of white filter paper

tapered roller bearings with grease if expired can not be used if it will not pay attention to tapered roller bearings have a huge damage , so you must learn how to determine whether the oil can be reused .
1 droplets traces Act
Take a clean sheet of white filter paper , drip a few drops on a filter paper , until the oil leak , if the angular contact ball bearing surface of black powder , there is resistance astringent sense of touch , then the oil which has a lot of impurities , good oil -free powder , hand feels dry and smooth , and the yellow marks.
2 hand twist method
Lubricant between the thumb and forefinger twist repeated grinding, good hand feel lubricating oil , less wear debris , no friction, if the sense of the sand and the like have a larger sense tapered bearing manufacturer of friction between the fingers , then the lubrication impurities in the oil , can not be reused and should be replaced with new oil .
3 Light Law
In the sky on a clear day , the oil lifted with a screwdriver , angle of 45 degrees with the horizontal . Control the sun, observe droplets case, in the light , you can clearly see that no oil debris as well, inheritable effects if too much debris , replace oil .
4 oil flow observation
Take two cups , one containing oil to be checked , the other empty on the table , the cup will be filled with oil held 30-40 cm high and tilted away from the desktop , allowing oil to flow slowly empty cup observed their activities , good quality lubricating oil stream should be slim , average , continuous, if thrown oil flow unsteadiness , and sometimes there are large shed , said that oil has gone .