A leaking toilet supply line
The short hose feeding your toilet is a common source of sudden floods.
Updated · 3 min read
Bottom line
A toilet supply line is the short hose from the wall valve to the tank. Drips at either nut, bulges or cracks mean it should be replaced. Close the stop, flush to empty the tank, unscrew both ends and fit a new braided line.
Contents
Why these lines fail
Older plastic or rubber supply lines harden and crack over time. Plastic nuts on the tank end can split if overtightened.
Hard water adds mineral crust at the threads. With Monterey Park's city well water averaging 220 mg/L, per the water quality report, crust often shows up as white or green deposits at the connections.
What to look for
- Moisture or crust at either nut
- A plastic line that feels stiff or looks yellowed
- A bulge in a rubber hose
- Rust or drips at the stop valve stem
Replacing the line
Turn the stop clockwise until it stops, flush to empty the tank, and sponge out the rest. Unscrew the nut under the tank and the one at the stop.
Fit a braided stainless line of the right length. Hand-tighten the tank end and give the stop end a gentle snug with a wrench.
When the valve is the problem
If the stop will not close or drips at its stem, replace it at the same time. Old multi-turn stops are common in houses from the 1950s and 1960s, which make up much of Monterey Park.
Before you call
How tight should the supply nut be?
Hand-tight plus a small turn. Overtightening can crack the tank fitting.
Can I reuse the old line?
No. A new line is inexpensive and the old one has already aged.
What if water still leaks after replacing it?
Check the tank's fill valve nut and the washer inside the tank, which can leak in the same spot.
Cited sources