Maytronics Dolphin 4 IoT dark grey brush assembly (CB) - 99955338-ASSY

Maytronics Dolphin 4 IoT dark grey brush assembly (CB)

This is the genuine Maytronics replacement brush assembly for the Dolphin 4 IoT CB QP NC robotic pool cleaner, supplied in dark grey with a climbing-brush (CB) configuration. The assembly carries the full-width bristle roller that scrubs pool floors, walls and the waterline as the robot navigates its programmed cleaning cycle, dislodging dirt, algae and fine debris into the suction stream.

Function and cleaning performance

The brush assembly is the robot’s primary scrubbing component. Its bristles rotate against pool surfaces to loosen bonded deposits that suction alone cannot remove. The climbing-brush geometry is calibrated for the Dolphin 4 IoT platform, maintaining consistent bristle contact across flat floors, curved walls and the waterline transition.

Compatible Dolphin models

This assembly is the direct OEM replacement for the Maytronics Dolphin 4 IoT CB QP NC. The Dolphin 4 is part of Maytronics’ IoT-connected range, controlled via the MyDolphin Plus app, and shares the CB (climbing brush) brush-tube architecture. Always verify your robot’s model designation and existing brush type before ordering to confirm fitment.

Signs that the brush assembly needs replacing

Visible bristle wear — splayed, flattened or missing segments — is the clearest indicator. Other symptoms include reduced scrubbing effectiveness, uneven cleaning patterns on walls, algae patches returning faster than usual, or audible grinding if the brush tube bearing has degraded. A worn brush also reduces the robot’s traction on vertical surfaces, causing it to slip before reaching the waterline.

Why genuine Maytronics parts matter

Aftermarket brushes are frequently manufactured to looser dimensional tolerances, which can cause premature bearing wear, uneven bristle contact and, in some cases, damage to the brush drive gear. A genuine Maytronics assembly is engineered to the exact bristle stiffness, tube diameter and end-cap geometry required by the Dolphin 4 IoT drive train, preserving the manufacturer’s cleaning performance and protecting the rest of the brush module from secondary damage.