First place I would check is the 4WD switch on the transfer case - make sure it was reconnected after the clutch job.
Next - the pump should run if you have constant 12V power on the red wire, so let's take a look at that - remove the pump from the vehicle so you can bench test it - connect the black wire to the battery negative and the red wire to the battery positive, the pump should start & run, if it doesn't, it's defective, if it does, cap the outlet with your finger, the pump should stop, and restart when you remove your finger.