To separate out and prevent potentially contaminant particles from entering engine. Air and fuel – dust particles and moisture. Oil – metal particles, sludge and carbon.
The percentage of dirt that a filter removes. The filter paper or 'media' determines what the oil, air or fuel has to pass through and where the dirt is trapped. The more twists and turns a particle of dirt has to take, the more likely it is to be captured.
The higher the efficiency, the higher the % of dirt retained by the filter. Filters are least efficient when new and become most efficient just before "plugging".
Media is a mixture of various fibres bonded together.
The media filters out the contaminants passing through the oil, air or fuel filter. Quality and quantity of media are very important. Some media may look similar but can perform differently. The function of filter media is to remove the greatest amount of contaminants while offering the least resistance to flow.
Generally a filter with more media has the ability to trap more contaminants than one with less. Few pleats means little media and low capacity. Irrespective, the media must contain the appropriate resins and compounds.
How long a filter lasts before clogging up. Dust-holding capacity of the filter determines how long its life is. The more high-quality paper inside the filter the more dirt it will hold and the longer it will last.
How easily air, oil or fuel flows through the filter. Minimising resistance to flow ensures that the engine is never starved of air, oil or fuel. Poor flow in a filter deprives engines of their vital needs, causing them to work harder, lose power and create rapid engine wear over shorter periods.
Given the importance of efficiency, life and flow, regular filter changes with a good quality filter provide optimum performance and engine life.
A micron a measurement equalling one millionth of a metre.
A measure of the pore size in the filter media. Expressed as either ‘Nominal’ or ‘Absolute’. Nominal Rating relates to the percentage of particles at a given size that a filter can capture. For example 10 microns at 90% means it will remove 90% of particles 10 microns in size. Absolute refers to the removal of all particles at a given micron size and larger ie. 20 micron absolute means 100% of particles 20 microns or greater will be captured.
The lower the micron rating, the greater the efficiency and hence the amount of dirt that is captured. Common oil filter micron rating is approximately 35. Human hair is approximately 70 microns. When comparing different filter brands micron rating, you need to make sure that the same test procedures have been followed.
It stops oil from draining out of filter and oil galleries when the engine is shut down and aids quick flow of oil to engine on start up. Not all filters require anti drain back valve due to the construction of the engine.
Should the oil filter become blocked, the valve will open allowing oil to flow into the engine. (Unfiltered oil is better than no oil).
Full flow is where 100% of the oil passing through the same media before entering the engine. Bypass filters are more restrictive and take a portion of the oil and filter out smaller particles that can or have passed through the full flow filter. Common in heavy duty applications. Some filters can be a combination of full flow and bypass in a single canister, e.g. Ryco Z334 in Toyota Landcruisers.
When the oil pressure valve temporarily sticks, it subjects the entire lubricating system to extreme pressures. Under these conditions the oil filter generally expands as the increased pressure tries to force the filter off the engine. Ryco filters are built to withstand 3 times normal operating pressure.
Because it is the most important filter. Unfiltered air (inducted contamination) will cause excessive engine wear.
The air filter should be changed in relation to operating environment of vehicle, eg in hot, dusty conditions more regular frequent change period is required. In any case recommend change every 12 months irrespective of conditions or distance travelled. A blocked air filter can significantly increase fuel consumption. In addition, it can increase cylinder bore wear due to excessively high fuel to air ratios.
To provide strength to the filter due to high air flows and provide fire protection in case of backfires.
Make sure correct filter was installed as per instructions.
(a) Check old sealing gasket was removed from engine mounting base plate and that plate isn’t damaged or warped.
(b) Ensure filter was correctly fitted with new sealing gasket.
(c) Check threaded stud isn’t damaged or loose.