1995 Chevy Tahoe flluid leak

I have a chevy tahoe and in the front left side its leaking some type of brown fluid.. now it leaks a pretty nice amount everyday.. i check oil everyday and its never low i checked brake flluid and it is not low also transmisson fluid and its fine... i checked powersteering fluid and its fine but its seems like its leaking from the gear box...what ever it is its been leaking for a few weeks please help