How to replace an APEX^™ pump motor

The APEX™ system uses a positive displacement pump and a precisely controlled stepper motor to supply fluid to a Uni-Roller® S2. If the system experiences issues caused by a faulty stepper motor, follow these steps to replace it.

Stepper Motor Replacement Procedure

1. Order a new stepper motor from Unist. Part number: 305428.
2. Remove the guard plate using a 5/32 hex key.

3. Disconnect the electrical plug on the motor.

   

    

4. Disconnect the lead screw from the pump:
   a. Break the jam nut free using an 11/32 open-end wrench.
   b. Remove the lead screw using pliers. Note: The threads are secured with blue Loctite.

   

5. Remove the 4 socket head cap screws holding the motor to the pump assembly using a 3/32 hex key.

   

6. Install the new motor by following steps 5-2 in reverse order. Be sure to apply a small drop of Loctite to the lead screw threads when attaching it to the pump.
7. Navigate to the manual control display, home the pump, and perform the Runout Pump operation.
8. Repeat the Runout Pump operation until all air bubbles are removed.
9. Acknowledge all alarms and resume normal system operation.