Maytronics Dolphin M400/M500 cartridge cover kit - 9991047-ASSY

Maytronics Dolphin M400/M500 cartridge cover kit

This is the genuine Maytronics OEM cartridge cover kit (filter door assembly) for the Dolphin M400 and M500 robotic pool cleaners. It forms the hinged access door over the filter cartridge bay, sealing the cartridge housing during operation and allowing quick, tool-free cartridge removal for rinsing or replacement. Without a sound cover, the cartridge cannot seat or lock correctly, directly reducing filtration efficiency.

Compatibiliteit

This kit is confirmed to fit the Dolphin M400, M400 IoT EU, M500, Supreme M4, and Supreme M5 robotic pool cleaners. Always verify your robot’s model number before ordering to ensure a correct match.

When to replace the cartridge cover

Replace this cover kit when the door no longer closes flush, the locking tabs are cracked or broken, the hinge is bent or fractured, or when water bypasses the cartridge bay and returns to the pool unfiltered. Physical damage from poolside drops is a common cause of failure on the M-series platform.

What the kit includes

The assembly ships as a complete cover kit — all hardware required to restore the cartridge door to factory specification is included in the box, making the swap straightforward for most pool owners without specialist tools.

Why genuine Maytronics parts matter

Aftermarket covers are frequently moulded to looser tolerances, causing the cartridge to shift during a cleaning cycle and allowing debris to bypass the filter. The genuine Maytronics part is manufactured to the exact dimensions of the original, ensuring the locking mechanism engages fully and the cartridge remains correctly pressurised throughout the cleaning run.