SHIMANO BR-M445 brake problem

[castoro]

Hi all,
I just got my new 2012 CUBE Attention delivered and after assembling the bike, I noticed that my rear brakes are loose.
Loose meaning when I lift the bike, spin the rear wheel and start slowly pressing the brake lever, I see the brake pads traveling a long way to the brake disc. The lever almost reaches the steering wheel and then the brake pads start to bite on the disc.
So that means there's a lot of clearance between the pads and the disc. How can I change that?
The brakes are SHIMANO BR-M445 hydraulic and they don't seem to have any adjustment on the lever.
In comparison, the front brakes bite almost immediately, so theres a very noticeable difference between the two brakes.

thanks

[xerxes]

There's no facility for adjusting the lever travel on most hydraulic brakes. They are supposed to self adjust as the pads wear. Try pumping the lever, it may be that the pistons are pushed into the caliper body a bit.

You might also find some of this useful: http://www.parktool.com/blog/repair-help/shimano-r-hydraulic-brake-service-and-adjustment

[castoro]

There was air in the rear brake system.
I know it for a fact because I was experimenting with the front brake system and ended up letting air into the system by accident.
So now I know I need to bleed the system to get good results.

P.S. The air that's in the system, it will probably try to get out to the highest point in the system, but my question is - the valve through which you put new oil in, is it a one-way valve, so the air can't get out, right?