1990 Toyota Camry Leak in the PSteering

I have a leak in the PSteering but I cannot find it. I have cleaned the unit off, looked at the tubes comming out of the reservoir and followed them down to the PS unit. I cannot for the life of me see where it is leaking. The area is wet with PS fluid and I have to refill it with about 8 oz every morning. The PS works fine unless it is low. This is wierd but I can hear fluid running when I take off, through the dash on the passenger side of the car in the same area??? I could not hear this before it was leaking. Is it leaking somewhere inside the firewall? Thanks.........