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Vacuum cannister differences


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My original vacuum ball got shattered into a thousand pieces and I’m noticing that there are quite a few variations on Ebay. Some are round and others are oval. Some have 1 inlet, others have 2 or 3. I bought the cleanest one thinking they are all the same but it only has one large inlet. I do not have a vacuum disconnect anymore but it would be nice to have the blend doors working. Does a single inlet ball equalize the pressure in the manifold enough that I can tee in the HVAC line elsewhere?

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HOrnbrod

  • HOrnbrodObsessive Comanche Disorder
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New members to the forum, and some longtime members too, post technical questions in this forum but do not provide specifics of the MJ they are referring to. Like:
 
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With tapatalk you have to go to the main page where it shows you the icons of the groups you are in. at the top there should be an icon of a person, then go to settings, then signature. Then you can add a signature to the group you want. But it will only add the signature when you use tapatalk, if you ever log in on a computer it will not input the signature.

 

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1 hour ago, 87MJTIM said:

The oval one is if you have cruise control.

Not sure this is true since I have seen round ones with cruise control. My best guess is that the double nozzled ones are an inlet/hvac and the 3 nozzled one is inlet/hvac/cruise control. This one just has one inlet and no outlets. How does that work?

1 hour ago, cruiser54 said:

Apologies. I have a 1987 4WD Comanche. Cannister apparently is from a 1991 Comanche. 

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18 minutes ago, 87MJTIM said:

Sounds like yours may have been changed in the past.  Factory CC used the football reservoir.  You indicated that the cannister is from a 91.

Chrysler used the same shape football for their HOs. It can be confusing to those who aren’t familiar with parts(thanks Chrysler). 
 

OP, you will need the same shape canister but with 4 holes, two per side. They are getting harder to find these days. 

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This is all great info. I do not have cruise control. I also do not have a CAD disconnect anymore. I'm trying to simplify the hoses as much as I can. What I’m still confused about is how a stock 1991 is routed if the cannister has a single “nub”. Is there no check valve anymore? I always assumed the HVAC remained the same throughout all the 1996-down years. How did they get vacuum for HVAC without a nub for it? 

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