I would start with bleeding the lines. Once you get the air out ( assuming the master cylinder works well enough to allow you to), any leaks should be easier to find.

Missing fluid is often from the back of the master cylinder. Anything else should be easy to spot.

87 Turbo Intercooled Raider, roller cam, torsen rear diff, LSD front diff, lockup auto with modified converter, V6 brakes, low transfer case gears...