Cherokee axle vacuum source

[98Chero]

where does the vacum come from, Im sure its from some part of the engine intake but my Chiltens manual dosnt show any vacum line going to my axel vacum motor. I am working on a 1990 cherokee limited. The problem Im having is the jeep wont go into all wheel drive when I put the transfer case lever in all wheel 4 hi.

 

[Jester32]

Theres a vaccum switch on the t case that controls it

 

[Bounty__Hunter]

Look for a red vacuum line from the intake manifold, across the firewall, and back to the transfer case. Then there's 2 black vacuum lines to the front axle, and one blue vacuum line that ends in a vent somewhere on the passenger fender.

Generally it's a vacuum problem if the front axle disconnect isn't working. Pull the vacuum plug from the front axle and feel for equal alternating vacuum between the two vacuum lines as somebody shifts from 2wd to 4wd and back.

 

[98Chero]

Im working on this right now. The t-case lever cover reads from inside the jeep like this.. 2wd hi... 4w part time...4w full time... nuetral...4w low. But the front axle only has a vent hose, not two vacum lines. apparently I dont have a command-trac front alxe and i can only see one hose connection going to the t-case and it dosnt have a hose connected to it. now Im not sure what I am working on here, maybe someone before me has done some parts replacement from other jeeps.

 

[Bounty__Hunter]

The Selec-trac 4wd with the 242 transfer case will have a non-disconnect front axle. What you're seeing is correct for your 4wd system.

 

[98Chero]

So I shouldnt have any vacum lines in my style of 4wd even to the t-case.

 

[carnuck]

Just a breather with the 242

 

[Bounty__Hunter]

So I shouldnt have any vacum lines in my style of 4wd even to the t-case.

Correct.

 

[98Chero]

well it was alittle confusing because the t-case bezel has 4wd part time and 4wd full time on it, but the front and rear axles stay the same. I was more interested in any vacum lines because broken cracked or leaking vacum lines can cause poor engine performance.