I have a 93 Toyota truck just the regular one not tundra and the front brakes will work first thing in the morning then they will start to not release and the peddle will be hard as a rock and won't depress. I have changed the m/c and rubber lines to the calipers when I tried to bleed them the front did fine the rear ones wouldn't bleed so I traced the line back to a valve I think is a load sencing valve and got fluid from a bleeder from there. The truck is ugly and has 300000 miles but runs great any ideas. I haven't ever changed the calipers.
