Home / Guides

Worn pool pump bearings: the signs and what to do

Updated : November 10, 2026 · Piscines VP

Worn bearings make a high-pitched squeal or whine that gets worse over the weeks, and the hand test doesn't change it. The most common cause is a leaking shaft seal that lets water into the motor. Replace the bearings (and the seal) or the motor before it seizes.

A pump motor spins on two ball bearings. When they wear out, the noise comes from inside: putting your hand on the motor changes nothing (see The hand test).

The signs

• A squeal or high-pitched whine, like metal rubbing.
• The noise gets worse week after week.
• Louder at start-up, then calms down a bit.
• The motor runs hotter than usual.
• Sometimes water or rust under the motor.

The most common cause

Between the pump and the motor, a mechanical shaft seal keeps the water out. When it wears, a trickle of water runs along the shaft into the front bearing. The bearing rusts, then squeals. If you see water under the motor, have the seal replaced before the bearings go.

Other causes: motor age, running the pump dry, or a motor in full sun with poor ventilation.

What to do

1. Have the pump checked soon: seized bearings can burn out the motor.
2. Depending on the motor’s age: replace the bearings and seal, or replace the motor.
3. If the pump is more than 8 to 10 years old, compare with a variable-speed pump, quieter and cheaper to run.

What bearings are not

If the noise drops when you put your hand on the motor, it isn’t the bearings: it’s vibration. See Noisy pool pump.

Piscines VP repairs and replaces pool pumps in Laval and the Basses-Laurentides, Quebec.

Not sure of the cause? Take the 2-question diagnosis →

Read next