I have a 1994 Honda Civic. I just replaced the front (pads) and rear (bands) brakes and this is the 3rd time that I doding by myself. After I finish in bleed and pump the brake, I notice that the bake pedal was still very loose and going all the way down, and sometime getting hard (intermitent). I went to a close mechanic shop and told that it could be the master cylinder. Any ideas?
Sounds like a Master Cylinder problem.
check for a brake fluid leak at one of the calipers or wheel cylinders. if there is no leak, it’s probably the master cylinder
Improperly adjusted rear brakes can mimic a faulty master cylinder so make sure the rears are properly adjusted.
And for a simple brake replacement why are you having to bleed the brakes?