Tune-Up or Maintenance Equipment - Oil Filters

A specially treated paper filtering element contained in a metal screening is the prime component in virtually all oil filters. The paper is pleated into an accordion fold for maximum surface area and the metal screen is used to hold the paper in place and prevent its collapse under the high pressure that builds up in the oil system. Filter quality is determined by the minimum- sized particle that the filter is capable of stopping. A 10-micron rating, for instance, will stop a particle measuring approximately .0004 inches, but still allow the oil to circulate freely in the system.

• Spin-On Filters:

Most cars are equipped with spin-on filters. These come with the filter enclosed in the canister. When changing the unit, the used canister is thrown away. When selling this type filter, always consult the catalog; although the filter might appear outwardly to fit on a given car, there is a good chance that the gaskets might not seat properly or that the bypass valves might not function. Special wrenches are available for use with filters of this type.

• Long-Life Filters:

Dual or long-life filters are basically spin-on filters equipped with two filtering elements. The main paper filter handles the flow of oil under normal driving conditions. As oil pressure builds, pressure valves release some of the oil and channel it through a second element often made of a synthetic material such as rayon. This relieves back pressure and prevents clogging as oil pressure increases. As the pressure declines, the valves close and redirect all of the oil through the main filter element. 

• Cartridge-Type Filters:

Cartridge-type oil filters, used primarily on older cars, fit into a canister that is mounted on the engine. The filter and the canister lid must be seated properly to prevent oil leaks and to ensure that the oil passes entirely through the filtering element.