Maytronics Dolphin Supreme M5 diaphragm 2010 – pair - 9991046-ASSY

Maytronics Dolphin Supreme M5 diaphragm 2010 – pair

This is the OEM pair of rubber diaphragms (part 9991046-ASSY) used in the Dolphin Supreme M5 and a wide range of compatible models. Each diaphragm acts as a rapid-drain flap at the base of the robot, opening under gravity when you lift the unit from the water and closing under suction during operation to maintain hydraulic integrity inside the cleaner’s pump circuit.

What this diaphragm does in the Dolphin

During cleaning, the diaphragm seals the drain port so the impeller can build and sustain the suction needed to pull debris into the filter basket. The moment you lift the robot clear of the water, the flaps open and drain the body rapidly, so you’re not carrying a tank of pool water back to the equipment pad. Without a serviceable diaphragm, the robot either loses suction mid-cycle or fails to drain at lift-out, adding unnecessary weight and stress to the cable and swivel.

Which Dolphin models it fits

The 9991046-ASSY diaphragm pair is confirmed to fit the Dolphin Supreme M5, Supreme M4, M200, M400, M500, C3, C3 Dynamic, C4, Nautilus Plus, Nautilus CC Plus, Triton Plus, Oasis Z5/Z5i, Wave 60, Wave 65, Wave 80, Wave 90, Sigma, Odyssey, Aquaris XL, and Liberty. Always cross-reference your robot’s model number and parts schematic before ordering if your model is not listed.

Signs it needs replacing

Visible cracking, warping, or stiffness in the rubber is the most obvious indicator. Functionally, watch for reduced suction performance despite a clean filter, water pooling inside the robot body at the end of a cycle, or the unit feeling excessively heavy when you retrieve it from the pool. A diaphragm that no longer seats flat will also cause intermittent suction loss during the cleaning run.

How to install it

Flip the robot upside down and locate the two drain-port covers on the underside of the chassis. Each diaphragm is retained by a simple push-fit or single-screw clip depending on the specific chassis revision — no specialist tools required. Remove the worn flap, seat the new diaphragm flat against the port, and secure the retaining clip. The full swap takes under ten minutes per side.