Fluidmaster Inc 242 Replacement Rubber Diaphragm

Product Description

The FLUIDMASTER INC 242 is a replacement rubber diaphragm designed to restore proper fill valve operation in toilet ballcock assemblies. The diaphragm seats inside the ballcock cap and controls water flow by flexing open and closed with changes in water pressure. When a diaphragm wears out, cracks, or loses elasticity, the ballcock may fail to shut off fully, causing a running toilet or inconsistent fill. Installing a fresh 242 diaphragm returns the ballcock to correct seating and flow control without replacing the entire fill valve assembly. Plumbers and experienced DIYers handle this repair during routine toilet maintenance or in response to a running or slow-filling toilet complaint.

This diaphragm is intended for repairing 100 or 200A through 400A series Fluidmaster ballcock assemblies. It is a common repair part in residential plumbing applications where older-style ballcock fill valves remain in service. The repair is typically performed during a tank rebuild or when a toilet audit reveals a worn or deteriorated diaphragm seal. Sold as a single unit, the 242 is a straightforward, low-cost fix that avoids a full valve replacement.

Key Features

• Direct replacement diaphragm for Fluidmaster 100 and 200A-400A ballcock fill valves
• Rubber construction maintains flexibility and sealing performance across normal water temperature ranges
• Restores proper flow shutoff and eliminates running toilet caused by diaphragm failure
• Lightweight at 0.3 pounds for easy handling and shipment
• Sold individually for single-valve repairs

Compatibility

Compatible with Fluidmaster 100 and 200A through 400A series ballcock fill valve assemblies.

Installation Notes

Installation is performed by a licensed plumber or qualified DIYer during toilet tank service. Before beginning, shut off the water supply at the angle stop valve and flush the tank to drain residual water. Remove the ballcock cap per the manufacturer procedure, swap the old diaphragm for the new 242, and reassemble before restoring supply pressure. Follow all applicable local plumbing codes, including IPC requirements for potable water fixture repair.

Technical Specifications

• Weight: 0.3 pounds
• Unit of Measure: Each
• Package Quantity: 10

Standard Information

• Brand: FLUIDMASTER INC
• Manufacturer Part Number: 242