An oil filter forces lubricating fluid through a porous media, typically cellulose, synthetic glass fiber, or wire mesh, to trap abrasive particles, wear debris, and soot. Filters are rated by their micron size and capture efficiency. Maintaining clean oil through proper filtration prevents three-body abrasive wear and extends the life of both the lubricant and the machine components.
Grab a strap wrench and swap out that oil filter, then cut the old one open to check for metal flakes.
Always pre-fill large spin-on oil filters before installation if the mounting orientation allows it, which prevents a dry start while the pump fills the empty housing.
Related terms
Kidney loop
Off-line filtration circuit that continuously pumps reservoir oil through a filter and back.
ISO cleanliness code
Three-number code for how many particles above 4, 6 and 14 microns are in a millilitre of fluid.
Particle count
Count of solid particles per volume of oil, sorted by size, used to track dirt and wear debris.