a vacuum hose diagram. This is sometimes printed on a placard in the engine bay. If not, look one up in the service manual or consult an online service such as ­AllData. You don’t want to ...

First, check under the hood to see if you have a label there that depicts the hose routings, as that will streamline the process of locating the vacuum hoses ... while the engine is running.

The pumping of an engine’s pistons creates a vacuum in the cylinders, and that vacuum is filled by air drawn in through the intake system. If leaks develop in hoses or engine parts downstream ...