from what i can remember, you need to make sure the ones out of the master cylnder are the same as theones going from the valave block
it's not just a case of "this pipe goes there and this goes there"

you need to make sure you aren't crossing them over

there are also possible issues with getting the air lock out of the valve block

i'll go and have a look at which pipe goes where, they might even have different sized fittings