Aladdin Diffuser Square-Ring, Jacuzzi Magnum, O-462-9

The Aladdin O-462-9 is the diffuser ring for the Jacuzzi Magnum pump. It has a square section rather than the round profile of a normal o-ring, and it measures 3 inches across the outside, 2-3/4 inches across the inside, and 1/8 inch thick in both directions.

What the diffuser ring does

The diffuser caps the impeller and steers water into the volute. The ring seals the joint between the diffuser and the housing. When it hardens, flattens or splits, water short circuits back around the impeller instead of leaving through the discharge, and the pump moves less water for the same effort.

Fitting it

Take the old ring out, clean the groove properly and check the seat for scale before the new one goes in. Because the profile is square, it needs to sit flat in its groove all the way round. A round o-ring of the same diameter is not a substitute.