Why does my basin faucet jump when I use the sprayer?

Why does my basin faucet jump when I use the sprayer?

Turn off the basin faucet set water supplies.
Disassemble and remove all internal faucet components.
Place and hold an upside-down bucket over the faucet to deflect water into the sink.
Carefully turn water supply on and let run one minute.
Turn water supply off.
Reassemble the faucet.
Turn water supply on.