Priming the PSD pump
When a PSD unit has lost prime due to accident or inadvertent emptying of the reservoir during installation the easiest way to reprime the unit without disassembling and bench priming is to get a mity-vac on the bleed nipple on the valve block. With the reservoir filled apply vacuum to the bleed nipple. As soon as you start to get a drop on the fluid level apply power to the pump ensuring the positive and negative leads are in the proper spots. You should be able to hear the pump gaining traction with the fluids and the fluid level dropping. Ensure you do not go below the low mark on the reservoir. Once you are getting flow from the pump remove the Mity-vac and continue with the pump running until there are no bubbles. Closing the bleed valve will allow the PSD unit to build pressure. Once this happens follow the directions for bleeding the PSD slave and lines.
This process may be repeated as necessary but ensure you do not over heat the pump.