Fluidmaster PerforMAX Toilet Fill Valve & 2" Adjustable Flapper Repair Kit — 2" Flapper, Quieter Fast Refill

Fluidmaster K-400H-039 is a complete toilet repair kit that replaces a worn fill valve and installs an adjustable 2" flapper to restore efficient, quiet, and reliable toilet flushing.

This kit pairs Fluidmaster's PerforMAX high-performance fill valve with a 2-inch adjustable flapper to update older or underperforming toilets. It’s engineered to fit most 2" flush valve openings and to simplify installation with tools-minimal adjustments. The components are designed to reduce common issues like running toilets, noisy refills, and inconsistent flushes without requiring a full tank replacement.

How does the PerforMAX fill valve improve toilet refilling?

The PerforMAX fill valve delivers a faster, steadier refill and reduces vibration and noise compared with many original equipment valves. Its design helps maintain a consistent water level, which lowers the chance of overflow or late refilling that causes nuisance running.

• High-flow pathway for quicker tank refill
• Stable seal to prevent post-flush running
• Corrosion-resistant materials for longer life
• Adjustable height to fit multiple tank depths

Will the 2" adjustable flapper stop leaks and ensure full flushes?

The included 2-inch flapper is adjustable so you can control the flush volume and stop water from leaking into the bowl. Correctly setting the flapper reduces phantom flushes and helps the toilet deliver consistent flush performance across varying water pressures.

• Adjustable settings to tune flush strength and conservation
• Resilient rubber compound for reliable sealing
• Compatible with standard 2" flush valve openings
• Replaces worn or brittle factory flappers easily

How easy is installation for a DIY homeowner?

Installation is designed for straightforward DIY replacement: shut off water, drain the tank, remove the old parts, and fit the new fill valve and flapper. The kit includes the main components and clear adjustments so most home plumbers can complete the swap in under an hour with minimal tools.

• Fits most conventional toilets with 2" flush valves
• Tool-light installation—common household tools required
• Adjustable height and float for fine tuning after installation
• Step-by-step adjustments reduce callbacks

What maintenance or adjustments should I expect after installing the kit?

After installation, you may need to fine-tune the water level and flapper setting to balance flush power and water use. Routine inspection once or twice a year keeps seals and connections performing well and helps catch mineral buildup in hard-water areas.

• Adjust tank fill height for optimal bowl refill
• Periodically check flapper seal for debris or wear
• Clean or replace parts if mineral deposits form
• Minor readjustments may be needed with changing water pressure

Who is this for: The Fluidmaster K-400H-039 kit is aimed at homeowners, rental property managers, and DIY plumbers who want a reliable, cost-effective way to fix running toilets, noisy refills, or weak flushes without replacing the entire tank. It’s especially useful for older toilets with a 2" flush valve that need updated components to restore efficient operation and reduce water waste.