Toto THU096 Flapper Gasket CST85 Series

Product Description

The TOTO THU096 is a replacement flapper gasket designed for use in TOTO toilet flush valve assemblies. The gasket creates the watertight seal between the flapper and the flush valve seat, preventing water from continuously draining from the tank into the bowl. A worn or degraded flapper gasket is one of the most common causes of a running toilet, and replacing it restores proper flush performance and stops water waste. This part is installed by licensed plumbers and experienced DIYers as a routine maintenance component. At 0.4 pounds, it is a compact, lightweight part.

The THU096 is intended for TOTO CST85 series two-piece toilet models. It serves as a direct OEM-spec replacement gasket, ensuring proper fit against the flush valve seat geometry specific to these units. This type of repair is common in residential and light commercial plumbing maintenance, typically performed during a toilet tune-up or in response to a confirmed running-toilet diagnosis.

Key Features

• OEM-spec replacement gasket engineered to fit TOTO CST85 series flush valve assemblies
• Restores watertight seal between flapper and flush valve seat
• Stops tank-to-bowl water loss caused by a degraded or deformed gasket
• Lightweight component at 0.4 pounds for easy handling during service
• Direct replacement part minimizes diagnostic time and callbacks

Compatibility

Designed as an OEM-style replacement flapper gasket for TOTO CST85 series toilets.

Installation Notes

Installation is performed by a licensed plumber or qualified service technician. Before replacing the flapper gasket, shut off the water supply at the toilet stop valve and flush to empty the tank. Inspect the flush valve seat for mineral buildup or scoring before installing the new gasket, as a damaged seat will cause the replacement to fail prematurely. Follow all applicable plumbing codes per the IPC for toilet component replacement.

Technical Specifications

• Weight: 0.4 pounds

Standard Information

• Brand: TOTO
• Manufacturer Part Number: THU096