the little rubber cap in the center of the lid won't stay in, it keeps popping out when i blend.

Diagnosis

The central rubber stopper on the BBL620SIL lid is a friction-fit vented cap designed to allow steam and pressure to escape while preventing large chunks of food from ejecting. When this cap pops out during a blend cycle, it is typically due to a failure of the airtight seal or a loss of structural tension in the silicone. This happens because the cap relies on a precise diameter to create a vacuum-like grip against the inner rim of the lid. The root cause is usually one of two things: thermal degradation or residue buildup. If the cap has been exposed to high-heat drying cycles in a dishwasher, the silicone can warp or expand, reducing the grip strength. Alternatively, a thin film of dried smoothie or protein powder can accumulate on the rim of the lid or the outer edge of the cap, acting as a lubricant that allows the cap to slide out once the internal pressure of the blending vortex reaches a certain threshold. You can confirm this by attempting to pull the cap out with light pressure; if it slides out without any resistance, the seal is compromised.

How to Fix It

1. Deep Clean the Interface: Remove the rubber cap entirely. Use a damp microfiber cloth and a small amount of white vinegar to scrub the inner circular rim of the lid and the outer circumference of the rubber cap. This removes invisible oils and residue that cause the cap to slip.
2. Inspect for Deformity: Lay the cap on a flat surface. If it doesn't sit perfectly flat or appears "bowed," it has warped. If it is warped, you can sometimes reset the shape by dipping the cap in boiling water for 30 seconds and then immediately plunging it into ice water to shrink the silicone back to its original tension.
3. Correct Orientation: Ensure the side with the small, recessed ventilation holes is facing down toward the blending jug. The smooth, slightly convex side must face up.
4. The "Snap-Seat" Technique: Instead of simply pushing the cap in, place it in the hole and apply firm, downward pressure while slightly twisting the cap clockwise. This ensures the silicone "bites" into the plastic rim of the lid.
5. Pressure Test: Before starting the motor, press down on the center of the cap with your palm to ensure it is flush with the lid surface. There should be no visible gap between the rubber and the plastic.

If That Didn't Work

• Apply a Food-Grade Sealant: If the silicone has stretched over time, apply a tiny amount of food-grade silicone grease or a drop of coconut oil to the rim. While it seems counterintuitive to add lubricant, a tiny amount of high-viscosity oil can actually create a better hydraulic seal that resists the "popping" effect of air pressure.
• Check Lid Warpage: Inspect the main plastic lid for any cracks or bowing. If the lid itself has warped from heat, the center hole may have expanded, making it impossible for the original cap to fit snugly. If the hole is oversized, the cap will always pop out regardless of its condition.
• Replacement Part: If the rubber has permanently lost its elasticity (common after 2+ years of heavy use), you will need a replacement lid assembly. Search for the BBL620 specific lid replacement; avoid generic "universal" blender lids as the pressure venting on the Fresh and Furious is specific to its high-RPM motor.
• Reduce Fill Volume: If you are filling the jug to the "Max" line with heavy ingredients, the internal pressure is significantly higher. Try reducing your load by 10% to see if the lower pressure prevents the cap from ejecting.

Heads Up

• Avoid High-Heat Drying: Never put the rubber cap in the "Sanitize" or "High Heat" cycle of your dishwasher. The extreme heat breaks down the silicone polymers, leading to the exact stretching and popping issue described.
• Avoid Over-Tightening: Do not use tools to force the cap in. If you over-stretch the silicone during installation, you will permanently ruin the friction fit.
• Check the Gasket: While fixing the lid, check the main jug gasket. If the main lid isn't sealing tightly against the jug, air can leak in and create turbulent pressure that pushes the center cap outward.
• Pre-Blend Pulse: Always start with 2-3 short pulses before switching to a continuous blend. This helps settle the ingredients and prevents a sudden "air pocket" from blasting the cap out of the lid.