93 breakaway...
Air leak in front above brake fluid resv....air manifold.....appears to be a vacuum generator...air blows out and there is vacuum on one of the two lines coming out of the device

Both lines coming go to a softball sized container... cruise control ?.....' t ' in one vacuum line with smaller line ....

Help

If you are still stock, there are two vacuum generators. One up front that you found and one in the engine compartment.

The up front runs the ducting for the heat/ac system and the rear is used for the cruise control. The softball is the vacuum storage device. Normally when full vacuum is reached the air is shut of until more vacuum is needed.

This description is kind of an oxymoron. There is no such thing as a vacuum, but an absence or reduction of air pressure. Just as there is no such thing as cold. Cold is an absence of heat.

Thanks gary
Should there be less pressure at both ports ?.... mine spits pressure even with both hoses pinched off....is it bad and where do I get another one ?

You can not "pinch off" to test. While it is operating there will be the sound of air escaping out of the free port, that is how it works. One port will have a loss of air pressure (vacuum)while the other will have higher pressure and air coming out. Unfortunately these units are no longer made and very difficult to find new! It is originally a Ford part but have been discontinued.

If you are getting a vacuum signal out of one of the ports, then it is probably working. if you "pinch off"the vacuum port, and the air OUT of the other port stops, yes it is probably good, however, if the air continues to come out then it is BAD!

HTH

Makes sense....except it always bleeds air until the front pressure gauge reads zero .....is this normal ?...should it be on a solenoid so it's only on when the dash fan is on or something ?..... removing it for now.....pipe plug .temporary fix....

Does the one in the rear work the same?.....haven't looked for that one yet.... the rear air pressure stays up for days...

How do I fix this ..... help

I haven't researched it much, but mine have valves inline with the vacuum generators. When the air pressure gets to low the air to the generator shuts off. This keeps the generators from draining the air tanks.

Even though the Ford generators are no longer available, there are many other units available that will work. I have a cheap harbor freight unit used as a evacuator for ac systems, that could replace the original.

Unless the generator corrods it should never go bad. All you have is air blowing across an orface. Might get dirty and need to be cleaned.

I believe that the black orb you are referring to is for the Acme dash air conditioning system. Here is a good site for information http://soldbyrichard.com/rvacheaterparts.php. The owner worked for Acme for sixteen years and is quite knowledgeable about the systems.

Both my vacuum generators failed in the same manner, they would not shut off. Shortly later the rear generator used for the cruise control stopped working but would continue to use air. I found it very bad to use the brake air system for this purpose. I also didn't like the continual cycling that the air pump had to go thru. More wear and tear on the pump and the drying system.

I replaced the cruise control system with a home brew all electrical system and used a motorized vacuum pump for the HVAC control system.

Anything you add/change to the brake air system MUST be thought out so you don't bleed off the tanks too quickly or becomes a liability while driving.

Mine isn't a straight vacuum oriface.... I has a diaphram that appears to regulate it .....what harbor freight. Item replaced it ?

I didn't say I used a Harbor Freight unit, but I could. The item is #96677 and under $20.