I have a 2007 Sport and every time I stepped down to use the brakes they almost went to the floor. I replaced the master cylinder, flushed out and bled the brakes and still nothing... maybe a tiny marginal difference. It got bad because I was afraid to drive in the rain. At the same time I noticed that I had to pull the e-brake up pretty far so I adjusted the drums and... what do ya know.... the brakes are again firm and good to go.
It seems that the brakes were so far out of adjustment that they weren't grabbing at all. It's annoying to have to do that. Usually I'd replace the brakes myself but ONCE i had the rear brakes done because I was being lazy. I won't make that mistake again!!! I guess they never adjusted them after putting them in.

 

In order to adjust rear brakes, the parking brake should be used on regular bases, however, under some condition during winter it causes rear brakes to freeze. So it may be a god practice to cycle a parking brake when idling (perhaps at light)
Also at least every other oil change it is a good idea to take a rear drum out and clean the brake dust

 

It's a manual so I use the parking brake all the time. Not sure why it wasn't self adjusting but it's fine - I took care of it. I wish I knew how to make it self adjust though. I probably wouldn't have needed to replace the master cylinder and bleed the brake lines which is, of course, a time consuming pain in my ass. I'm just happy to be back in business with firm braking.

 

While we've NEVER had the braking work as bad as you, I don't think that the drum self-adjusters work that well. Not only on the Fit, but on ANY drum braked car.


I remove the drums once a year to lube the shoe backing plates, and adjust the star wheel. It DOES make a noticeable difference!