Cordless vacuum makes a whistling noise and suction seems reduced

Safety first: Remove the battery before inspecting for leaks.

• Check joints: Assemble the vacuum and run your hand around joints and seams while it runs (briefly, with battery installed) to feel for escaping air. Then remove the battery.
• Inspect seals and gaskets: Look at the rubber seals on the dust container, wand, and nozzle. Replace any that are flattened, torn, or missing.
• Check for cracks: Examine the wand and nozzle for hairline cracks. Replace cracked parts.
• Ensure tight fit: Push all connections firmly together until they click.