gents97civ

Hey guys i have a problem with my 97 ex. It seemed like all the sudden I have less braking. Like the pedal isnt as stiff as it used to be. Kind of like I have faded braking but all the time. If I use the ebrake half way and then apply the pedal it seems to be normal. I checked the back pads and they have about 1/8th left, no rivets. I was thinking one of a few things.

1. Pads need changed
2. Master is going bad
3. rear adjusters not working
4. air in the line

any help is appreciated. and if anyone knows how to adjust the rear brakes let me know I didnt really want to mess with it. without someone giving me a how to