In Reply to: Strange thing with my bakes...... (more) posted by Mr M Coupe on August 06, 2000 at 17:32:12:
If whoever bled it drained the fluid down instead of sucking it out of the reservoir, air could have gotten into the master cylinder. I've had a few that had to be removed and "bench bled" because I couldn't get the last little bubbles out any other way.
One of your bleed screws may be a tiny bit loose. Check them and wipe any fluid away thoroughly. If there's moisture around one the next day, there's a leak. Overtightening them can cause this, too, as does a metal shaving or a tiny particle of dirt on the seating surface.
Last resort - remove the new pads and check to be sure there isn't a tear in a caliper piston seal. You can get a piston "cocked" while pushing them back into the housing, and damage the seal trying to get the piston to retract. I once saw one that was just unfolded, so it didn't seal against the piston.