There arent really any moving parts to "go bad" on a breather...but yes they can get clogged causing problems....

The fluid has to be either brake fluid or gear oil...

put a piece of white paper under it and see what it is...gear oil will have a more greasy feel to it than brake fluid

Im still betting that there is a hole in the housing under that brake line bracket...take it off and see...

Looking at it closer it almost looks like that might not be a factory weld holding the bracket on

 

That's what I thought, but the crumby pic makes it hard to tell.

 

I can take a better picture this evening of that bracket. Thanks for all of the help everyone. I very much appreciate it.

Two more questions:
1.) If it is in fact a hole in the diff housing itself could it just be sealed up by a weld to seal it up?

2.) When refilling the housing after changing the diff oil, I fill it from the large bolt about halfway up the diff, right? Also, do I just need regular gear oil, and how much will a stock diff take?

 

1. YES

2. YES.....2.2 quarts ...fill it until it is completely full and starts running out the fill hole..make sure you can get the fill plug out first before you drain it...

 

Replace the diff fluid with 75-90w or 80-90w. The fill and drain plugs are 24mm.

 

Alright, so it was diff oil that was leaking. It is definately coming from under/around that brake cable mount that is welded to the rear diff. Since I can't tell exactly where the hole is I decided to go with some JB weld. So I applied generous amounts of jb weld around that mount, so it'll set tonight/tomorrow and I'll test it out tomorrow evening and change the oil as well at that time.


My guess for the cause of the hole was either that the factory messed up and put one of those welds a bit too deep and it is just now rusting out into a hole, or is just straight up rusted through. The former sounds more realistic, however.