Pressure‑Assist 1.6 GPF Toilet Tank Replacement System for Two-Piece Toilets, M-101526-F31, 503 Series

This 1.6‑gallon pressure‑assist tank system is engineered for reliable performance in two‑piece pressure‑assist toilets, offering powerful flushing action and consistent flow. It is designed specifically for systems originally equipped with Flushmate III 503‑series technology, ensuring compatibility and dependable operation. Built to fit a wide range of OEM two‑piece pressure‑assist toilet tanks (except for the Kohler K‑4404 tank and Gerber 28‑385 tank models), this replacement system delivers strong drain carry and reduces the need for repeat flushing.

It uses pressure rather than gravity, producing a vigorous flush that meets performance expectations in both residential and commercial environments. The system includes key components such as the vessel (1.6 GPF), tank nut, and essential gaskets for tank‑to‑bowl integration—providing a complete solution for maintenance or replacement needs. Flushmate systems push waste up to 33% farther than ANSI minimum standards, providing superior drain carry for high‑use environments such as hotels, commercial buildings, multifamily housing, schools, and residential settings.

To verify that M-101526-F31 is the correct replacement system for your Flushmate system, please verify that the serial number on the label located on the top of your existing Flushmate unit contains the following information:

• Right-hand, left-hand, push button handle location
• Maintains consistent flush volume throughout long‑term usage.
• Compatible only with 12‑inch rough‑in tanks for proper installation.
• Helps reduce double flushing through high‑flow pressure‑assist operation.
• Designed as a full replacement system for existing Flushmate M‑101526‑F3 setups.
• Fits OEM 503‑series systems except Kohler K‑4404 and Gerber 28‑385 tank models.
• Designed for use with two‑piece pressure‑assist toilet tanks for dependable operation.
• Suitable for high‑demand environments such as hotels, schools, and commercial restrooms.
• Pressure‑assist technology delivers stronger flushing performance compared to gravity systems.
• Provides a 1.6‑gallon pressure‑assist flush system compatible with Flushmate III 503‑series toilets.
• Includes all installation components: system vessel (M-101526-F31), tank‑to‑tank gasket (A-323288), shank locknut (B-103021), discharge extension locknut (A-119221-1), and tank‑to‑bowl gasket (E-205288).
• Fits Porcelain Brands: American Standard , Briggs, Contrac, Corona , Crane Plumbing, Eljer , Exergis, Gerber , Glacier Bay, Kohler , KooHoo, Laufen , Mansfield , Niagara, Orion , Peerless , ProFlo, Seasons, St. Thomas Creations, Universal Rundle, Vitromex , Vortens/Lamosa , Western , Winfield, Zurn