OK. I expect some sarcastic remarks but I am asking anyways. While searching for vacuum leaks, I came across a vacuum hose near the battery (1991 YJ) that seems to dead end. This hose comes from the botton up, takes a 180 degree bend downwards, then dead ends into a small back fitting with several holes and is white inside.

What makes me suspicious is the white part is too white to always have been this way.

BTW: The problems started when I installed my 1" MM and BL.

Sounds maybe like the vacuum fitting for the light that tells you if your in 4wd or not. Does your 4wheel light work? Not sure exactly what your describing, sounds like its not connected but not sure a picture would help. I'll go look at my YJ and report back if looking at it clears anything up.

My 4wd light works because I went wheeling today and it was on. The hose is right next to the battery and is covered with the same plastic protection you see on electrical wiring bundles. The hose comes up, then bends completely downward towards the ground and ends with small black plastic circular attachment. I wish I had a digital camera to take a picture, but I dont.

I assume the small black circular piece you are describing is maybe a one way valve? I think I remember ripping that piece off of mine when I removed the tcase to d30 vacuum harness out (I ran 1 vacuum line to the axle disconnector so its locked all the time)but I do recall blowing into it and it would only let me blow thru one way and it was a round black disc sort of thing.


...now that I think about it I think the charcoal canister is over there by the battery and a check valve could be appropriate for that, I have not looked at my YJ yet as it has been raining here but I think it could be not a vacuum line you are describing but maybe a vent for the dana 30?

Are you sure it's not your t-case vent tube? That's what it sounds like.

Originally posted by withamc
Are you sure it's not your t-case vent tube? That's what it sounds like.

I am gonna need to go check to see if thats what i ripped off. That would explain the condition of my tcase fluid :shaking: