1989 Toyota corrolla Alltrac Fluid Under Dash?

Have oil/fluid leaking under dash on brake pedal. Most resent repair, a rebuilt head at 93,000 miles and a master cylinder done by me, 6 months ago. Already inspected brake lines to and from master cylinder am about to check booster but not sure on how, or would fliud leak through firewall from booster. Help
please



took of lower dash panel and did not see any sign of leaking, however aluminum braket that supports steering column has a puddle of oil in it? This area in question is directly below insrtument panel.
Ive double checked firewall area for leakage and cant see any sign of line or hose leaking? Baffeled