So tried looking this evening,but mosquitos were kicking my ***,so I couldn't figure it out. Is the breather check valve the metal block on the axle tube or the plastic piece that's in the frame near the filler neck for the fuel?

 

This is for my '00 8.25 rear. The metal block is your rear brake hose. There is a hole in the metal block that the breather tube that comes out of the axle goes through. The hose attaches to that and goes into the uni-body. No idea of what is in the uni-body. The top hat breather like for the front that is in your engine compartment or a check valve of some sorts.

This is the top hat one for the front:

https://www.summitracing.com/int/par...6101/overview/

I bought mine at the Jeep dealer. Paid $3.79 with tax. Part # J5352955. I ran hose so now my rear diff breather is in the engine compartment too.

 

So in the rear,is it the piece that's screwed into the brake block on the axle,or do you assume it's what's in the uni-body?

 

There is the metal tube coming out of the axle that has the nut on it. The metal tube goes through the metal block that is part of the rear brake hose. Then secured with a nut. This is what keeps the brake hose in place. The rubber hose runs up inside the uni body and that is where there the breather or check valve, not sure cause can't see in there, is.

 

Oh ok! Thank you!

 

I took the hose off from the metal tube and blew through it. I didn't get any back pressure. I also sucked on it and I couldn't create a vacuum. I put the hose onto metal tube and did the same thing. I was able to create back pressure and vacuum that did not leak at all. I took the metal tube out to see if it's clogged and it's clean as whistle. I looked inside the hole in the axle to see if it's gummed up,and that's clear as well. I'm not really sure the exact results I should be seeing. I got thrown off a little by the metal tube not letting anything in or out even though it's clear. Any ideas? I'm sorry being an amateur at this. I've never had issues like this on my previous car.

 

It is just a breather. So my guess is when you take the hose off at the brake hose end and can blow air through it then you are good. Why are you messing with this anyway?

 

Because first I had gear oil leaking from where the driver's side axle meets the pumpkin,so I changed the oil and gasket to see if that'd help because at the time I couldn't tell exactly what was leaking. Now it leaks from the fill plug area whenever I drive it,so there's gotta be something wrong here. I put the exact amount of oil required,so I didn't over fill.

 

I understand now. I am not sure what would be right. Guessing here I want to say that taking the hose off the metal tube and blowing out air should just flow freely. But if you pull the hose off the uni-body side and blow out the rear is kinda sealed and air tight so it would be like blowing air into a plastic soda bottle. Can only get so much in there. Maybe remove your diff plug and try cause I am thinking with that out air should also flow freely. Did you try a new diff plug like I suggested in your other thread. Rubber will deteriorate over time.

 

I used a new plug and threw some silicone adhesive on it and seemed to stop coming from the plug. I think using the thicker oil stopped it from coming out around the axle. It seems fine now I guess lol.