I recently purchased a 1994 Ranger 5 speed with only 75,000 miles. I have noticed that the brakes seem to be working except when at a stand still and constant pressure is applied to brakes the pedal will slowly go all the way to the floor. Is this a bleeding problem (air in the line) or something more serious, like a master cylinder problem. Any advice would be appreciated. The fluid is full and I don't see any obvious leaking going on. If you let off and re-apply pressure the brakes get firm but will slowly go down again. Thanks in advance.
Scott