Lesson 4/Learning Event 1
After the oil has been filtered, it is sent through the main oil line to the parts requiring lubrication.
The abrasives removed from the oil by the filter will eventually clog the filter to the extent that no oil can get
through if the filter is not serviced. When this happens, a bypass valve, which is usually located in the filter,
opens and allows the unfiltered oil to move into the main oil line.
Although most modern automotive engines are equipped with the full-flow type of oil filter, there are many
engines that have the bypass type of filter.