What is bypass?

bypass valve

Glossary “bypass valve” Definition:
Valve in the oil filter that opens to allow unfiltered oil flow to the bearings when the oil is cold and thick or the filtering material is plugged due to a lack of proper maintenance. Any valve that opens under certain conditions to permit a flow of liquid or gas by some alternate to its normal route.

bypass

Glossary “bypass” Definition:
1). A passageway between the head and block or behind the water pump that allows a water pump to circulate coolant throughout the cylinder head and engine block before the thermostat opens. 2). A valve that is used to regulate pressure or control the quantity of a liquid or gas. 3). A shunt or parallel path around one or more elements in a circuit.