Fluidmaster 400A Universal Toilet Fill Valve — Brass Shank, Adjustable Height & Easy Turn-Dial

Fluidmaster 400A Brass Shank Universal Toilet Fill Valve is a durable, adjustable replacement fill valve that fits most toilets and simplifies water-level control and installation.

If your toilet is running, refilling slowly, or the plastic shank on the old valve is damaged, the Fluidmaster 400A offers a brass shank upgrade that resists corrosion and leaks. The unit includes a pre-installed shank washer and an intuitive turn-dial adjustment to set tank water level for efficient performance. Designed for a broad range of toilet tanks, it replaces many common OEM fill valves and helps reduce installation time for DIYers and professionals alike.

How does this valve improve toilet reliability?

The brass shank provides a sturdier connection at the tank wall compared with many all-plastic valves, lowering the risk of cracks and leaks over time. The internal mechanism maintains consistent fill operation and reduces the frequency of adjustments. Because the shank resists corrosion, it stays watertight longer in both hard and soft water conditions.

• Solid brass shank for long-term leak resistance
• Stable fill action to prevent running toilets
• Compatible with a wide range of toilet tank openings

How easy is it to install in a household toilet?

Installation is straightforward for anyone comfortable turning off water and removing the tank lid. The valve ships with a pre-installed shank washer so you avoid looking for small parts during assembly. No special tools or tank modifications are typically required, and the valve height can be adjusted for different tank sizes.

• Pre-installed shank washer reduces installation steps
• Adjustable height fits most modern tanks
• No extra seals or adapters needed in most installations

What water-saving or adjustment features does it offer?

A simple turn-dial on the top of the valve lets you lower or raise the tank water level to reduce flush volume without changing the flapper or other parts. This makes it easy to optimize water use for your household preferences or local water-conservation goals. Adjusting the level also helps eliminate phantom flushes caused by improper fill height.

• Easy-turn dial for precise water level control
• Helps reduce unnecessary water usage when set properly
• Quick adjustments without removing the valve from the tank

Will this part fit my toilet model?

The 400A is a universal-style fill valve engineered to fit most toilet tanks; it replaces many common OEM valves in single- and two-piece toilets. Because it features an adjustable height and standard shank thread, compatibility is high, but confirm your tank’s mounting hole and clearance before purchase. If your toilet has a nonstandard or extremely shallow tank, measure to ensure the valve can be adjusted to the proper height.

• Universal fit with adjustable height for varied tanks
• Standard shank thread matches most supply line connections
• Measure tank depth and mounting hole diameter when in doubt

Who is this for: The Fluidmaster 400A Brass Shank Universal Fill Valve is aimed at homeowners, rental property managers, plumbers, and handy DIYers who want a reliable, longer-lasting replacement for worn or leaking fill valves. It’s especially well suited for situations where a stronger shank and quick water-level adjustment are priorities, or where a simple, tool-light replacement will save time and prevent future leaks.