What is this?
Thread Starter
Member
Joined: Mar 2010
Posts: 202
Likes: 0
From: Virginia Beach
Year: 1991
Model: Cherokee
Engine: 1998 4.0 242
Passenger side fender. One end looks like it goes into the dash and the other looks like it’s ripped off. Can’t find anything it would connect to. Thanks.
Junior Member

Joined: Nov 2016
Posts: 44
Likes: 1
From: Lakewood, WA
Year: 1999
Model: Cherokee
Engine: 4.0
Looks like you may have a vacuum leak. The unconnected end should go to the vacuum reservoir in the front right of the bumper. If you google "jeep cherokee vacuum reservoir" you will be able to see where it should be located.
Senior Member

Joined: Jul 2012
Posts: 794
Likes: 105
From: Aldie, VA
Year: 1999
Model: Cherokee
Engine: 4.0
I have used a smaller diameter tube to go between the broken sections as a temporary fix when that tubing breaks and messes up your vacuum system. Of course my temporary fix has been in place for about 3 years now so I guess it's permanent now.
Old fart with a wrench
Joined: Nov 2010
Posts: 14,398
Likes: 741
From: Manlius, east of Syracuse, NY
Year: 2000 XJ Sport & WJ Laredo
Model: Grand Cherokee (WJ)
Engine: 4.0L
That vacuum line comes off the manifold and goes thru a check valve to the heater control, cruise control accuator, then to the vacuum reservoir. The reservoir holds enough vacuum to close the air doors in the heater when you shut off the engine. It also helps the cruise control react to changes instantly. Right now your IAC is compensating for the leak as well as it can.
Thread Starter
Member
Joined: Mar 2010
Posts: 202
Likes: 0
From: Virginia Beach
Year: 1991
Model: Cherokee
Engine: 1998 4.0 242
That vacuum line comes off the manifold and goes thru a check valve to the heater control, cruise control accuator, then to the vacuum reservoir. The reservoir holds enough vacuum to close the air doors in the heater when you shut off the engine. It also helps the cruise control react to changes instantly. Right now your IAC is compensating for the leak as well as it can.
Interesting. I don’t have cruise control and it’s pretty long. I also thought it went to the manifold because it reaches it perfectly but it must of been plugged off. You know exactly which nipple it goes too? Weird thing is no codes and Jeep runs great.
Junior Member

Joined: Nov 2016
Posts: 44
Likes: 1
From: Lakewood, WA
Year: 1999
Model: Cherokee
Engine: 4.0
That T fitting is where your CC, if you had it, would feed from for the vacuum input. My jeep was disconnected there when I bought it. Ran great, but the fan would only flow out of the defrost ports, which is a tell tale sign that the vacuum isn't getting to the climate control panel. The post below will be a big help to understand the vacuum system with diagram. Older Jeep XJ, but still relevant.
Check out this post
Check out this post
Trending Topics
Thread Starter
Member
Joined: Mar 2010
Posts: 202
Likes: 0
From: Virginia Beach
Year: 1991
Model: Cherokee
Engine: 1998 4.0 242
That T fitting is where your CC, if you had it, would feed from for the vacuum input. My jeep was disconnected there when I bought it. Ran great, but the fan would only flow out of the defrost ports, which is a tell tale sign that the vacuum isn't getting to the climate control panel. The post below will be a big help to understand the vacuum system with diagram. Older Jeep XJ, but still relevant.
Check out this post
Check out this post
Thread Starter
Member
Joined: Mar 2010
Posts: 202
Likes: 0
From: Virginia Beach
Year: 1991
Model: Cherokee
Engine: 1998 4.0 242
It was missing. Went to Pick n Pull today and got the reservoir then Napa to get the rubber line. Heat works better and Jeep runs a little smoother. Thanks for y’alls help.
Old fart with a wrench
Joined: Nov 2010
Posts: 14,398
Likes: 741
From: Manlius, east of Syracuse, NY
Year: 2000 XJ Sport & WJ Laredo
Model: Grand Cherokee (WJ)
Engine: 4.0L
It looks like that new hose is rubbing on the battery ground cable exactly where the old hose had the hole. You should protect it somehow.
Thread Starter
Member
Joined: Mar 2010
Posts: 202
Likes: 0
From: Virginia Beach
Year: 1991
Model: Cherokee
Engine: 1998 4.0 242



