Replace the Pump Impellor Stack
Ensure that all electrical power is shut off and disconnected before proceeding. The
circuit breaker box or individual circuit breaker should be locked and tagged out by
personnel following this procedure. Remember that the CBL is a wet environment.
Serious injury or death to personnel can result from electrocution if proper safety
precautions are not observed.
Ensure graywater pipes have been sanitized IAW procedures contained in TB MED 577
before attempting any repairs. Failure to observe safety precautions may result in
serious illness or death from biohazards.
The P-4 pump is a multistage centrifugal pump, which has individual impellers and
impellor casings assembled as a stack. While the individual impellor components within
the impellor stack may be replaced, it is recommended that the entire stack assembly be
replaced in the event of damage or wear to these components.
1. Disconnect power and drain WTS IAW procedures given in TM 10-3510-226-10.
2. Remove guard panel.
3. Remove the screws retaining the coupling guard (Figure 4, Item 3), and remove the coupling guard.
4. Remove the bolts securing the coupling halves and remove the coupling (Figure 4, Item 4).
5. Remove the coupling pin from the pump shaft (Figure 4, Item 5).
6. Tag and disconnect motor leads.
7. Remove locknut retaining conduit (Figure 5, Item 8) and remove conduit.
8. Remove the bolts retaining the motor (Figure 4, Item 2) to the motor stool (Figure 4, Item 6) and
remove the motor.
9. Loosen the three screws securing the cartridge seal (Figure 4, Item 7) and unscrew the cartridge
seal from the motor stool (Figure 4, Item 6).
10. Disconnect the vent hose (Figure 4, Item 9) from the pump head.
11. Remove the nuts retaining the motor stool and pump head (Figure 4, Item 6) to the pump outer
sleeve (Figure 4, Item 10), and remove the motor stool.