The supply line connecting your wall valve to your toilet tank is one of the most overlooked failure points in a bathroom. Plastic supply lines crack, rubber ones degrade, and when they fail — they fail at full pressure. A braided stainless replacement costs under $10 and takes 5 minutes. Here’s what to buy.
| Product | Best For | Price |
|---|---|---|
| Fluidmaster B1T16 Braided Supply Line | Best Overall | ~$8 |
| Eastman 98394 Stainless Supply Line | Best Heavy Duty | ~$10 |
| BrassCraft CD24C 12″ Supply Line | Best Short Reach | ~$7 |
Best Overall: Fluidmaster B1T16 Braided
Braided stainless over a polymer tube — burst-resistant, corrosion-proof, and flexible enough to fit any standard toilet-to-wall configuration. The 3/8″ compression x 7/8″ ballcock connection fits virtually every toilet made in the last 30 years. Available in 9″, 12″, and 16″ lengths.
- ✅ Stainless braid — burst resistant
- ✅ Fits virtually all toilets
- ✅ Multiple lengths available
- ✅ Under $10
How to Replace a Toilet Supply Line
- Shut off the supply valve. Flush to drain the tank.
- Unscrew the supply line from the bottom of the tank and from the supply valve.
- Thread new line onto the supply valve (compression end) — hand tight plus 1/4 turn with pliers.
- Thread the ballcock nut onto the tank inlet — hand tight only (plastic threads strip easily).
- Turn water on slowly and check both ends for leaks.
Tip: If the line drips at the ballcock end, check that the rubber washer inside the coupling nut is present and not damaged before adding torque.
FAQ
What length supply line do I need?
Measure from the center of the wall valve to the center of the tank inlet. Buy the next size up — a little slack is fine, a line that’s too short creates tension and stress at the fittings.
My supply line is the corrugated chrome type. Should I replace it?
Yes — immediately. Corrugated chrome supply lines are one of the most failure-prone plumbing components ever made. Replace with braided stainless.
Bottom Line
Fluidmaster B1T16 is the best $8 you can spend on a toilet. Replace every corrugated or plastic supply line in your home with braided stainless — it’s cheap insurance against a flooded bathroom.