An oil filter is an equipment made to remove contaminants or dirt from engine oil as well as from other kinds of oils such as lubricating oil, hydraulic oil, and transmission oil. Crankcase oil filter, on the other hand, is simply the engine oil filter (the term ‘crankcase’ actually means engine).Click to see full answer. Considering this, what does a crankcase filter do?A crankcase filter is the filter in the crankcase vent. Cars today are designed to return the crankcase fumes back into the engine. The crankcase filter, also referred to as the breather filter, essentially captures the oil residue in the air that passes back into the engine.Also Know, what is the oil filter connected to? A central hole is threaded to mate with the oil filter assembly on the engine block. Inside the can is the filter material, most frequently made from synthetic fiber. The engine’s oil pump moves the oil directly to the filter, where it enters from the holes in the perimeter of the base plate. Secondly, what is a crankcase oil? A crankcase is the housing for the crankshaft in a reciprocating internal combustion engine. Four-stroke engines typically have an oil sump at the bottom of the crankcase and the majority of the engine’s oil is held within the crankcase.Can I use an oil filter in place of a hydraulic filter?There are filters on the market today that could interchange from a hydraulic system into a gravity-flow lube oil filter as long as the expected requirements are relatively the same. However, the flow rate, pressure, surface area and pore size must all be accounted for to achieve the expected results.