[GSMacLean]

imported post

smokepole wrote:

left a weight on pedal all night,
Hmmmmmm, my hand can't collapse pedal to floorboard
when the rain quits I'll have to try a test ride.
"fingers crossed"

Yup...putting pressure in the system by putting a weight on the pedal (or belt/bungee around the brake lever) causes air bubbles in the system to be compressed. Because they are compressed (i.e. smaller), they will fit through orifices that they won't normally make it through, and can gradually (overnight) migrate their way up to the master cylinder, where they're expunged.