Ok i found out why it didn't see the drive:
I deleted the "Backup" partition using Disk utility and with that my Recovery partition is gone too. I don't know why but deleted that too. I assume the two somehow connected.
Now i have to create a new partition and make bootable. I found this tutorial but apple recently released a RecoveryHDUpdate and i want to work with that.
So the problem is that i cannot to copy the content from the recoveryHDupdate disk image to a newly created partition.