Marlin 12704 Ballcock Coast 1B1 Replacement

Product Description

The MARLIN 12704 is a ballcock assembly designed as a replacement for the Coast 1B1 ballcock. A ballcock is the fill valve inside a toilet tank that controls water flow after each flush cycle. It opens when the float drops as the tank empties and shuts off when the water level is restored. Licensed plumbers and experienced service technicians install this type of component during toilet repair or renovation work. The 12704 is suited for standard residential toilet tank applications where the original Coast 1B1 fill valve has worn, corroded, or failed to shut off properly.

This ballcock is intended for residential toilet tank installations where a direct replacement for the Coast 1B1 unit is needed. It fits into standard tank configurations and is a straightforward swap for service calls involving running toilets, slow fill, or failed shutoff. No additional hardware is described in the available product data; verify fit against the existing tank dimensions and float arm clearance before installation.

Key Features

• Direct replacement for the Coast 1B1 ballcock assembly
• Controls toilet tank fill cycle by regulating water inlet flow
• Designed for standard residential toilet tank installation
• Compact assembly suitable for typical tank configurations

Compatibility

Specified as a replacement for the Coast 1B1 ballcock. Confirm tank thread size and float clearance before installation, as no additional model-specific compatibility data was provided.

Installation Notes

Installation is performed by a licensed plumber or qualified service technician. Shut off the water supply at the toilet stop valve and flush the tank fully before removing the existing ballcock. Follow local plumbing codes, including applicable IPC guidelines, for fill valve replacement and backflow compliance. Do not overtighten the locknut on the tank shank, as this can crack porcelain tank bases.

Technical Specifications

• Product Type: Ballcock (Fill Valve)
• Application: Toilet Tank

Standard Information

• Brand: MARLIN
• Manufacturer Part Number: 12704