I just installed Shimano's RS685 Levers with RS785 calipers, and I can't seem to get the rear brake to feel as firm as the front brake. The front brake bled easily and feels great, but the back brake still has some sponginess, and the lever moves closer to the bar than on the front. I have bled the rear brake about 7 times now, with no improvement. The front was bled once (after adding oil) and is rock solid.

My process is as follows, per Shimano Dealer Manual:

1. Pads removed, bleed block in place
2. Free stroke screw backed all the way out (read this can help, not mentioned in manual)
3. Caliper removed from frame so it is the lowest point of system
4. Pushed oil with syringe through caliper up to reservoir w/funnel until no more air bubbles appeared
5. Opened bleed port and let oil drain from top to bottom until oil flowed without air bubbles. Knocked line
and caliper to encourage stuck bubbles to move out
6. Closed bleed port, pulled lever to the bar and opened/closed bleed port quickly 3 times while keeping
the lever depressed.
7. With funnel still attached and bleed port closed, pulled the lever several times until air bubbles stopped
appearing in funnel.
8. Repeated last step with funnel tilted 30 degrees up, then 30 degrees down
9. Removed funnel, topped off reservoir with oil and installed o-ring and screw.
10.Backed in free stroke screw, installed pads and mounted/centered caliper.

I made sure that the funnel had plenty of oil in it at all times so I would not introduce any air into the system, and I used the Shimano Mineral Oil that was included with the brake/lever set.

I also noticed there were hardly any air bubbles present during the last couple of bleed attempts, leading me to believe I have most of the air out of the system. Is there supposed to be a difference in feel between the front and back brake? Does the longer hose have any affect on this? I will say the rear brake seems to work okay, but I wasn't expecting this much difference in "feel" between the front and rear levers.