Well I just went to look at the crossflow and only one side is moving. Not sure why that is, but it is. And since I still don't know how to do a teardown, I guess I will chalk it up to $130 wasted.
Suppose I'll contact reefbreeders to see if there is anything on there end they can do.
They're actually pretty easy to strip down (I have now stripped the rotors down also). I suspect the drive coupling isn't properly engaged as both rotors are driven from the same shaft.
I would check that the cartridge is fully pushed into the motor.
Here's how to strip them down:
You can remove the end caps with a bit of practice, however I find it easier to slightly bend the mount which releases one side of the pump from the mount, held in with a rubber vibration absorbing mount. (you can then release the end cap much more easily.
Pull the rotor cage/cartridge straight out of the motor, here's one side of the drive coupling:
Here's the motor end:
You can remove the coupling from the rotor side with your fingers, or gently with a pair of needle nose pliers (it just slides off the ceramic driveshaft).
To remove the rotor from the cage, stand the cage on it's end with the motor end facing down. You will see the ceramic shaft, sitting in a ceramic bearing with a vibration absorbing rubber mount surrounding it. Gently, use the end of the needle nose pliers to push the shaft and bearing down, which pushes the rotor and end cap out. Pull the rotor out.
Here's the exploded view:
Pt 2 coming up...
