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Valves (Shower & Bath)Pressure-Balancing Unit (PBU)

Valves (Shower & Bath)

Pressure-Balancing Unit (PBU)

K-304 or K-15701 PBU Installation

  • Discard the thick washers (#1 from Fig. 1). These washers are only used when installing a PBU in the Coralais® K-15877 valve.

  • If installing a new PBU with an existing mixer cap, install the medium O-rings, (#2 from Fig. 1), and large O-ring, (#4 from Fig. 1), onto the existing mixer cap (Fig. 2).

NOTE: If installing a new PBU with a new mixer cap, the new mixer cap will include the new medium O-rings and large O-ring.

NOTE: If installing a new PBU with an early pressure-balancing valve brass cap (three-ribbed stem model), the installation requires the GP876851 mixer and PBU combination. See the "Identify a Single Control Bath/Shower Valve" help topic for more information.

  • Place the small O-rings, (#3 from Fig 1), on the back of the PBU. The PBU location for the O-rings is oval-shaped but the small O-rings are flexible enough to fit into the location (Fig. 3).

  • Proceed by reinstalling the PBU and mixer cap into the valve body.


Coralais® K-15877 PBU Installation

  • Discard the medium O-rings, (#2 from Fig. 1), as the Coralais K-15877 mixer cap does not use these O-rings.

  • Place the small O-rings, (#3 from Fig. 1), on the back of the PBU. The PBU location for the O-rings is oval shaped but the small O-rings are flexible enough to fit into the location (Fig. 4).

  • Place the thick washers, (#1 from Fig. 1), on the front of the PBU (Fig. 4).

  • Install the large O-ring on the back of the grey PBU adapter plate (Fig. 5).

  • Reassemble the remainder of the valve (Fig. 6).

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