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Disconnect Water Supply Lines — Disconnect the Supply Line from the Shutoff Valve

Beginner

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How to Fix a Leak at a Faucet Supply Line Connection · Step 4 of 9

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In this video

After shutting off the water, disconnect the flexible supply lines that run from the shut-off valves up to the faucet connections under the sink. Use an adjustable wrench to loosen the nuts connecting the lines. Be prepared for a small amount of water to drip out from the lines. Have a bucket and a cloth or towel ready to catch this residual water.

Goal: Disconnect Water Supply Lines

  • Water will drip from the disconnected lines, even with the valves closed.
  • Place a small bucket or a towel directly under the connections to keep the floor dry.

Used in this video

  • Adjustable WrenchLoosening the nuts on the water supply lines.
  • BucketCatching residual water from the supply lines.
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FAQs

How long does this repair typically take for a beginner, and what's the real difficulty level?

This is a beginner-friendly project, usually taking 30-60 minutes once you have the right parts. The most challenging aspect is often working in tight, cramped spaces under the sink. Taking your time to ensure proper alignment and avoid cross-threading is key to success.

How do I know which new supply line to buy, especially regarding size and length?

Before purchasing, measure the length of your old supply line from end to end. Note the connection sizes: faucet connections are typically 1/2 inch FIP, and shutoff valve connections are commonly 3/8 inch compression. Bringing the old line to the store or taking a picture of the connections can help ensure you get an exact match.

I replaced the supply line, but it's still leaking. What should I check next?

First, ensure both ends of the new supply line are hand-tightened, then given an additional quarter to half-turn with a wrench – avoid overtightening. Check that the rubber washer (gasket) inside the supply line nuts is properly seated and undamaged. If the leak persists, the shutoff valve itself might be old and failing, or the connection point at the faucet could be compromised.

What if I can't turn off the water supply to my faucet, or the shutoff valve itself is leaking?

If the existing shutoff valve is stuck, leaking, or won't completely stop the water flow, you will need to turn off the main water supply to your entire house before proceeding. In such cases, or if you're uncomfortable with the main shutoff, it might be best to contact a qualified plumber, as replacing a main shutoff or a frozen fixture shutoff is a more advanced task.