Maytronics Dolphin Supreme M5 filter cartridge locking hook - 9980731

Maytronics Dolphin Supreme M5 filter cartridge locking hook

This is the genuine OEM locking hook that retains the filter cartridge inside the Dolphin Supreme M5’s cartridge housing. It clips directly onto the cartridge frame, holding it firmly against the housing during the full cleaning cycle. Without a functioning hook, the cartridge unseats under water pressure and the robot loses effective filtration.

What this locking hook does in the Dolphin

The hook engages a moulded catch on the cartridge housing to lock the filter cartridge in its operating position. It is the sole mechanical fastener between the cartridge and the body — if it breaks or loses its snap tension, the cartridge can shift or eject entirely mid-cycle, interrupting debris capture and potentially allowing fine particles to bypass the filter.

Which Dolphin models it fits

Part 9980731 fits a broad range of Maytronics robots that share the same cartridge housing design: Supreme M4, Supreme M5, Supreme Liberty, M400, M500, Wave 65, Wave 90, C3, C4, Oasis Z5, Triton Plus, and Nautilus CC Plus. Confirm your model before ordering — the cartridge housing must be the M4/M5-generation type for this hook to engage correctly.

Signs it needs replacing

The hook is typically made of rigid plastic and fails in one of two ways: the retaining tab snaps off completely, or the clip arms spread and lose grip tension so the cartridge rattles during operation. If you open the robot after a cycle and the cartridge has shifted position, or if you can flex the hook visibly without resistance, replace it before the next run.

How to install it

No tools are required. Open the cartridge access hatch, remove the filter cartridge, and unclip the worn hook from its seat on the housing wall. Press the new hook into position until you feel it snap home, then reinsert the cartridge and confirm it clicks locked before closing the hatch. The whole procedure takes under two minutes.