Step 7 · Connect Water Supply Lines
Attach the new flexible water supply lines to the threaded tailpieces of the faucet. Hand-tighten the nuts. Then, connect the other ends of the supply lines to the hot and cold water shut-off valves on the wall. The hot line is typically on the left and the cold on the right. Use two wrenches to tighten these connections: one to hold the shut-off valve steady and the other to tighten the supply line nut. This prevents putting stress on the plumbing in the wall. Tighten until snug.