I have replaced 2 crank seals and they still are leaking. on the seal itself do i have to push the middle part out when I am pushing the hub back on or do i just install the hub with the middle part of the seal going in like how u would install the waterpump seal like how the yellow part sticks out when u install it.

 

No it isn't like the water pump seal. Your hub may have a groove worn in it that is causing the leak.