Filters are Key to Long Vehicle Life

The Society of Automotive Engineers notes fluid contamination as the cause of 70- percent of failures of engines, transmissions and hydraulic systems. Filters are the key to eliminating, or at least reducing, contamination. For instance, engine oil does not wear out. Kept clean and free of contaminants by effective filtering, and if additives are replenished, engine oils will lubricate almost indefinitely. Also important to trouble-free vehicle life are air, fuel and automatic transmission filters.
Oil Filters

Most car, light truck and SUV engines use full-flow oil filters where all the oil passes through the filter before being circulated through the engine’s lubrication system. Oil enters the oil pump through the oil pick-up, a screened intake located near the bottom of the crankcase and is forced by the oil pump through the oil filter. Then “clean” oil flows to the main oil gallery and to the moving parts in the engine.

Contaminants come from three sources. First, they are built in during assembly, thus the importance of an on-time, initial oil and filter change on new vehicles and with new or rebuilt engines. Next, they are ingested with oil, gasoline and air, and therefore the need for more frequent oil and filter changes in dirty environments. And while today’s electronically-controlled engines burn much cleaner producing much less combustion byproducts, friction between moving parts still causes minute particles of bearings, cylinder walls, pistons, etc. to break off and circulate with the oil.

Because there is a huge number of different filters from several filter manufacturers, some distributors reduce the number they must inventory by consolidation. While filters look similar, caution is recommended when making substitutions. That’s because the internal components such as anti-drainback valves, by-pass valves, post seals and filtering elements may differ. Each of these has a specific purpose and must be considered when substituting filters to assure that the performance is not impaired. Substituting filters with "will fit" replacements that are not approved may affect or even void the warranties. Use only the product specified in interchange and application guides.
Air, Fuel and Automatic Transmission Filters.

While many motorists religiously change oil and oil filter, the other filters, especially fuel filters are often neglected. Air filters that are not excessively dirty can often be cleaned by blowing out the dirt with compressed air. However, make sure to blow from the inside outwards. Otherwise, you will merely force the particles further into the filter media. Make sure the correct filter is installed properly so there are no leaks since dirty air will seek the path of least resistance by-passing the filter.

While neglecting the other filters usually only result in premature wear and poor performance, a clogged fuel filter will result in a vehicle not running since fuel supply can cease in these full-flow filters. Properly functioning fuel filters are especially important in fuel injected engines because contaminants can plug the tiny passages resulting in poor and often expensive repairs to correct problems. Some fuel systems have more than one filter to be changed, for instance one near the fuel tank to trap larger particles and another under the hood to handle smaller contamination. Like other filters it important to use the correct replacement filters. For example, you might get away with a generic, plastic filter in the benign environment in the trunk, but it could result in a disastrous fire if installed in a hot engine compartment.

The best ways to keep an automatic transmission in good working order and prevent costly repairs is to change the ATF and filter periodically. While owners manual may only call for extended service intervals, up to 100,000 miles, more frequent intervals like every two years and 24,000 miles, are a cheap investment considering the cost of a transmission overhaul. In many transmissions, there is no way to drain the torque converter so you cannot replace the ATF without disassembling the entire transmission and thus significant amounts of old ATF is left in the transmission and thus another good reason for more frequent ATF and filter changes.