gajeepster

As we all know, vacuum control on the XJ is a tuff nut to crack. I have spent many hours dealing with an AC blowing thru Defrost Only problem tracing lines, locating vacuum diagrams and I'm getting warm as I've narrowed the problem down to the actuator controls. However, thru my discoveries, there are many discussions related to the Vacuum Canister located behind the passenger side of the front bumper. I have a 2000 Cherokee XJ Sport which in fact, does have this round Vacuum cannister out front but it is not connected to the vacuum system. If is my belief the cannister is only needed when the unit has cruise control. Can anyone confirm or set me straight? I find it strange that Jeep would install a component when it is not needed but go figure, I've seen stranger occurrences.

Put my mind at ease. Not back to tracing my vacuum problem.

wcupp

i believe and correct me if im wrong but this is from experience that the vacuum ball does affect what you problems are i hid a dear with my jeep a wile ago and broke that vacuum ball along with a small bend in the bumper i had no controll over where my air blew it just went out the defroster and my cruise didnt work so id say hook it up and see what happens

winston427

The vac cannister is needed for proper functioning of the air/heat vents. Without it you will only have airflow throught the defrost.

And wcupp, sorry but damn. Punctuation please.

94XjSport94

X2 the vacuum canister holds vacuum for the heat/air to blow out. Check your check valves on the system and make sure there aren't any dry rotted hoses. When i first started driving my XJ the air would do the same thing. My grandpa took it from me and pulled the Air control unit out and fixed the damper behind the unit that the arm from the setting switch goes to because it was stuck in defrost. Now it works great except for a little bit coming through the defrost but i guess thats normal, also happens when i drive without the air on, so if the switch is on red it blows hot air up and on blue cold air up the defrost.

wcupp

sorry had to run so i just typed that up real quick. Plus not so good with grammar

cpnwrench

Yes sir that vacuum canister(ball) at the front behind the grill is required to operate the vent/actuator doors for your heater control assembly. it is also used for the cruise control (if you happen to have it).

believe me I know.

cpnwrench

highmileage

you have to have the larger egg shaped canister for cruise control. but yes you have to have one if you don't want your vents and defroster changing every time you hit the gas.