If your toilet is running, phantom-flushing, or slow to refill, the fill valve and flapper are both likely worn. Instead of buying them separately, a complete tank repair kit replaces every internal component at once for about the same price as one individual part — and ensures everything works together. Here’s what to buy.
| Product | Best For | Price |
|---|---|---|
| Fluidmaster 400AKRP10 Complete Repair Kit | Best Overall | ~$18 |
| Korky 4010PK Complete Kit | Best for Performance | ~$20 |
| Danco 9D00053525 Complete Kit | Best Budget | ~$14 |
Best Overall: Fluidmaster 400AKRP10
This kit includes the 400A fill valve, a flapper, a flush handle, and a supply line — literally every component inside and connecting to a toilet tank. Replace everything at once and your toilet is as good as new for under $20. Works with most toilets built in the last 40 years.
- ✅ Replaces fill valve, flapper, handle, and supply line
- ✅ Fluidmaster quality throughout
- ✅ Universal fit
- ✅ Everything in one box
- ❌ Overkill if only one component is bad
How to Do a Full Tank Rebuild
- Shut off supply valve, flush to drain, sponge remaining water.
- Disconnect supply line from tank bottom.
- Remove old fill valve (unscrew locknut underneath tank).
- Unhook old flapper from flush valve pegs and disconnect chain.
- Install new fill valve, reconnect supply line.
- Install new flapper, connect chain with 1/2″ slack.
- Replace handle if included.
- Turn water on, adjust fill level, test flush.
Tip: A full rebuild takes 20 minutes and costs the same as a single service call to diagnose the problem. Do it all at once.
FAQ
How do I know if my fill valve or flapper is the problem?
Put food coloring in the tank. If it appears in the bowl without flushing — flapper. If the water level keeps rising or hissing persists after the tank fills — fill valve. If you’re not sure, replace both. It’s $18.
Bottom Line
The Fluidmaster 400AKRP10 is the best toilet repair purchase available. One kit, one trip, completely rebuilt toilet. Do it the first time a component fails rather than replacing parts piecemeal.