Mystery Hoses

[JeffM]

I have a 1976 440 Clipper.  While looking around underneath I discovered two small black hoses coupled together at the end with an L shaped female coupling hanging down beside the alternator. They look like vacuum hoses. The valve cover gaskets were recently replaced. They may have gotten unplugged from something during the replacement. Any ideas what they and what they connect to?
Jeff Milligan ACOC#3426

[HPotter]

If these little hoses are REALLY small, like on the order of 1/8 inch, they may have to do with the heater and A/C controls. This system is largely vacuum operated, controlling shutters to direct air flow, etc.

Harold, #886

[Guinnessecco]

Those little hoses, if they are vacuum lines for smog control equipment, or vacuum advance on the distributor can be important.  Check under the hood for a diagram of where those hoses go, and make sure connections are right and hoses are in good shape with no cracks.  Smog hoses that are off can give you a rough idle, and a vacuum advance will hit you hard in the pocket book because of poor gas mileage.  I replace eight feet of hose myself last time I had the engine cover off.

[alhnelson]

There are also a set of vacumn hoses that are molded into a connector (somewhat L type) that fit on the thermal valve for the EGR. That valve, if present, is designed to shut off vacumn to the EGR valve until after the engine reaches a certain tempature. On my engine, the valve was in the alternator area however my color coding had various striped colors not black. Look around the front of your block and see if you have a valve screwed into the block that is missing a vacumn connection. Just a possibility.