Long story, short: I got a '97 Ranger with the 2.3, four cylinder that got a mouse into the engine compartment and ate the vacuum line that goes to the vacuum reservoir and also the line that goes from the vacuum reservoir to the under dash controls. The mouse did a good job of it, as both hoses are completely gone. Okay, a few questions here: There is a bare plastic vacuum nipple underneath the coil that is open. Is that the vacuum nipple that goes the the reservoir? If so, does it matter which reservoir nipple hooks to the intake vacuum and which nipple hooks to the under dash controls? Is there a check valve somewhere in this system that keeps vacuum in the reservoir during acceleration, either inline or inside the reservoir?
My neighbor lady has a '98 Ranger with the 2.5 engine. I looked at her truck, but hers is missing the vacuum reservoir so it did me no good. TIA.

 

Kruse, not sure where to start. The 98 neighbor's truck has a vacuum reservoir on the passenger side located between the plastic fender apron and the metal fender outer. Depending on which plant the truck was made, the vacuum reservoir might be located on the passenger side rear of the radiator support. You can see the small vacuum lines going to it by tracing the vacuum valve that sits off flow to the heater during a/c operation. Vacuum reservoirs do not have an internal check valve, they just rely on vacuum volume to perform an operation to open or close the heater control door.

Most likely, the open nipple located below the coil pack would.connect to a bimetal valve on or near the air cleaner. The bimetal valve would direct heated air from the exhaust manifold heat stove to the air cleaner until the bimetal heats up and closes. Your 97 may have the odd duck round air cleaner design that sucks clean air through a funnel connected to the passenger fender inner.

Basics of the vacuum system starting with the intake manifold include the vacuum tree with lines connected to it. The biggest line would go the the brake booster. Smaller lines connect to the Climate control system, air cleaner and maybe some emission controls. The climate control vacuum line would route from the vacuum tree to the reservoir. The line from the reservoir to the heater and a/c door would route from the reservoir into an electrical harness bundle passing through the dash to behind the glove box door vacuum actuator motor. I do not think it matters which reservoir nipple is the intake or exhaust since the reservoir is empty inside.

Hope this helps, but if you have additional questions, don't wait to long as my memory fades more each day.