The Filtermaster SB30 takes a mechanical seal for a 3/4″ shaft with carbon / ceramic faces. This aftermarket seal replaces Onga 700270 and Astral 75508, and the same seal is listed for the Filtermaster SB20, AstralPool CX180, CX240 and CX280, and Onga Pantera PPP750, PPP1100 and PPP1500. Compare it with your old seal or measure the shaft before fitting.
Signs the Filtermaster SB30 seal is leaking
A mechanical seal is a pair of faces pressed together by a spring: one turns with the shaft, the other sits fixed in the pump body. A thin film of water keeps them cool. Grit, dry running and plain wear eventually let water past, and it then tracks along the shaft towards the motor.
- Water dripping or weeping from the join between the pump housing and the motor.
- White scale or rust streaks below the motor end.
- Air drawn in at the motor end, so the pump struggles to hold prime.
- A growing rumble from the motor after a long leak, a sign water may have reached the bearings.
SB30 seal part numbers and pumps that share it
This seal for the Filtermaster SB30 replaces Onga 700270 and Astral 75508. If your old seal or its packet carries either of these numbers, this is the matching replacement.
The same 3/4″ seal is listed for the Filtermaster SB20, AstralPool CTX, AstralPool CX180, AstralPool CX240, AstralPool CX280, Onga Leisuretime LTP1100, Onga Pantera PPP750, Onga Pantera PPP1100 and Onga Pantera PPP1500. It is also used in other pumps including the Filtermaster FM Series and FX Series, Poolrite Enduro and Quietline, Waterco Charger, Spa-Quip Maxiflo and a range of Onga and Davey models. It is sold on its own as our 3/4″ pool pump seal.
Fitting a new seal to the SB30
Isolate the power, close any valves and drain the pump before opening it. Remove the impeller to reach the old seal, and clean the seat recess so the new stationary seat presses in square. Keep the polished faces free of grit and finger marks, slide the spring half onto the shaft, then refit the impeller. Never run the pump dry once it is back together, because the faces need water to stay cool. If the capacitor is also due, the SB30 service kit pairs this seal with a run capacitor. Other Filtermaster models are listed on our Filtermaster service kits page.
Before you order
Check the old part before fitting: match the size of your old seal.