after washing my area rugs, the crosswave is leaking water from the bottom near the brush.

Diagnosis

The leaking issue near the brush roll on the Bissell CrossWave 1785A is typically caused by a failure in the vacuum's suction-to-flow ratio. When the machine is set to "Hard Floor" mode while cleaning a thick area rug, the pump dispenses a higher volume of water than the suction motor can recover from the rug's dense fibers. This creates a "flood" state where excess water pools at the base of the brush roll housing, eventually bypassing the internal seals and leaking from the bottom of the chassis. Furthermore, this leak is often exacerbated by a partially clogged dirty water tank filter or a saturated brush roll. If the suction is diminished—even slightly—the machine cannot pull the liquid upward fast enough to keep up with the dispensing pump. You can confirm this by checking the dirty water tank; if you see large bubbles but very little water being collected despite a wet floor, the suction is blocked, forcing the water to leak out the bottom instead of being pulled into the tank.

How to Fix It

Follow these precise steps to stop the leak and reset the machine's fluid balance:

1. Immediately power off the unit and remove the dirty water tank. Empty the tank completely to ensure there is no back-pressure preventing suction.
2. Remove the brush roll by twisting the locking mechanism. Inspect the brush roll for tangled hair or debris, specifically around the ends of the roller. Any buildup here prevents the brush from creating a tight seal against the floor, allowing water to leak sideways.
3. Clean the foam filter located at the top of the dirty water tank. Rinse it under cold water until the water runs clear, then let it air dry completely. A damp or clogged filter reduces suction by up to 40%, causing the "overflow" leak at the base.
4. Reinstall the brush roll and tank. Fill the clean water tank only to the "Max" line using the official CrossWave formula; using thick, third-party soaps can clog the internal nozzles, leading to uneven water distribution.
5. Switch the mode setting. Press the mode button located near the trigger until the "Area Rug" icon is illuminated. This setting reduces the water flow rate to prevent oversaturation.
6. Perform a "Recovery Pass." Move the vacuum forward and backward slowly over the wet area. Do not rush; the machine requires a slow pace to effectively vacuum up the liquid it just dispensed.

If That Didn't Work

• Check the Dirty Water Tank Gasket. Inspect the rubber seal where the tank connects to the main body. If the gasket is pinched, cracked, or missing, the vacuum will lose its prime. This loss of suction causes water to pool at the brush roll and leak from the bottom because it cannot be pulled upward into the tank.
• Inspect the Suction Path. Use a flashlight to look into the intake port where the brush roll meets the chassis. If a piece of debris (like a coin or small toy) is lodged there, it creates a partial blockage. Use a flexible bottle brush or a vacuum hose to clear the path.
• Verify the Pump Prime. If the machine is leaking but not dispensing water correctly, there may be an air lock in the pump. Hold the trigger down for 30 seconds while the clean tank is full to force air out of the lines and establish a steady flow.
• Test the Brush Roll Wear. If the bristles are significantly worn down (flattened), the brush cannot "flick" the water toward the suction intake. If the bristles are shorter than 1/2 inch, replace the brush roll (Part #206015) to restore the mechanical lift of the water.

Heads Up

• Never use bleach or abrasive chemicals in the clean water tank, as these can degrade the internal rubber seals and lead to permanent chassis leaks.
• Always empty the dirty water tank the moment the "Full" float reaches the top. Allowing the tank to overfill can cause water to enter the motor housing, which may lead to electrical failure.
• Store the CrossWave with the brush roll removed and the tanks empty to prevent mold growth and prevent the brush bristles from permanently flattening.
• Avoid using the "Hard Floor" setting on any surface with a pile higher than 1/4 inch, as this is the primary cause of water overflow and bottom-leakage.