Maytronics Dolphin Supreme M5 lower cover 2010 (Ex 45 CB) - 9980700

Maytronics Dolphin Supreme M5 lower cover 2010 (Ex 45 CB)

This is the OEM lower cover (bottom cover) for the Maytronics Dolphin Ex 45 CB platform, sold under the 2010 revision of the part. It forms the underside closure of the robot’s chassis, enclosing the active brush housing bay on units equipped with a third centre brush. On the Supreme M5, it sits directly against the pool surface and takes the bulk of abrasion during every cleaning cycle.

What this lower cover does in the Dolphin

The lower cover seals and protects the active brush housing at the base of the chassis. It retains the active brush assembly in alignment, shields the internal gear train from grit ingress, and maintains the hydrodynamic profile that keeps the robot tracking flat on the pool floor. A cracked or missing cover allows debris into the brush drive mechanism and disrupts suction geometry.

Which Dolphin models it fits

This part was released on the Ex 45 CB platform and is confirmed to fit the Dolphin Supreme M4, Supreme M5, Supreme M5 Liberty, Dolphin C3, Dolphin C4, Dolphin Wave 65, and Dolphin Wave 90. Always cross-reference your robot’s serial number before ordering — the Supreme M4 and M5 share a common chassis assembly, but later M400/M500 variants use this same bottom cover.

Signs it needs replacing

Inspect the lower cover if you notice the robot leaving the pool floor mid-cycle, if you hear a grinding noise from the brush drive area, or if you find visible cracks, chips, or warped mounting tabs when you lift the robot out of the water. A broken retaining clip or a cover that no longer seats flush is equally reason to replace — even a small gap lets fine sand reach the active brush bearings.

How to install it

Turn the robot upside down on a clean, dry surface. Release the existing lower cover by disengaging the retaining clips around the perimeter — no tools required on most Supreme M5 variants. Seat the replacement cover so all clips engage with an audible click, verify there is no gap at the brush bay aperture, and check the cover sits flush before returning the robot to the water. Total time is typically under five minutes.