Vacuum emits a high-pitched whistling noise and suction seems reduced.

Safety first: Remove the battery before inspecting seals closely.

• 1. Localize the leak: Run the vacuum briefly (with battery) and move your hand around joints and seals to feel for escaping air. Then remove the battery.
• 2. Inspect gaskets: Check the rubber gasket around the canister lid and inlet port. Look for flat spots, tears, or hardened rubber.
• 3. Check hose cuffs: Flex the hose near the ends while listening for changes in the whistle. Replace the hose if cracks are found.
• 4. Replace seals: Install new Milwaukee-compatible gaskets or O-rings on the lid and hose connections.
• 5. Reassemble and test: Reinstall the battery and test suction. The whistling should be gone and suction improved.