What is this hose for?

[WahooSteeler]

Noticed recently a hose hanging low under driver side of front axle, kind of in a loop. Tonight noticed it laying on the ground. What is this hose for, vacuum line? Notice the plastic connector on the end. 

[Pete M]

is that the axle vent?

[Green Mesa XJ]

Looks like axel vent to me


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[WahooSteeler]

That would make sense. Anybody got a pic of where it is supposed to attach to?

[gogmorgo]

Yeah. Looks to me like the breather for the diff. Should go to the top(ish) of the pumpkin. The end on the ground has a small filter just to keep dust out, and IIRC the factory put it on the firewall, but it really just needs to be somewhere clean-ish that won't get submerged; the tube will start sucking if the air inside the diff is cooled down rapidly (by dunking the axle in cold water) and the warm air in the diff shrinks, so you want it as high up as reasonable. Sorry I can't get you a pic, both my Jeeps are buried in snow out in the yard right now.

The only other tubes going to the axle apart from brake hoses are the vacuum lines for the CAD, which if memory serves are flexible black plastic, about 1/4"" OD. That doesn't look like them.

[gogmorgo]

Actually check that. Found an existing pic of my XJ where it's visible, barely. The black upright bit  over top of the emissions sticker. As indicated by the arrow. 

Although I can't guarantee that's the factory spot. 

This flip-phone quality photo of my MJ I think makes it look like it's hanging out under the brake booster, if you trace the hose up from the axle. 

[Cre8tive]

[Dzimm]

Factory location for the axle breather is tied to the main loom by the brake booster. This is a 98 XJ but you can see it just under the firewall ground cable. 

 

[WahooSteeler]

Thanks for the posts guys. You can see the "plug" on the end of mine like the pic from Dzimm so looks like I just need to zip-tie it back up. That said, mine doesn't seem long enough to reach up to the brake booster even though I assume that's not critical as long as it has good reach up in to the engine bay above any potential water line. 

[mjeff87]

I ziptied mine to the C101 bracket.  Just make sure you don't route it near the exhaust manifold on its way up and yer good