The AstralPool CX180 uses a mechanical shaft seal for a 3/4″ shaft with carbon / ceramic faces. It replaces Astral part 75508 and Onga 700270, and the same seal is listed for the AstralPool CTX, CX240 and CX280. This CapacitorsNZ seal is an aftermarket replacement to suit the CX180; measure your shaft or compare it with the old seal before fitting.
Astral 75508 and Onga 700270: part numbers this seal replaces
This seal replaces Astral 75508 and Onga 700270. If the packet from a previous seal or a parts list for your pump shows either number, this is the matching seal. The same seal size turns up under different numbers because pumps from several makers use it.
It is also sold on its own, without a model name attached, as our 3/4″ pool pump seal. That is the same part; this page simply makes it easier to find for CX180 owners.
Other pumps that use the same seal as the CX180
The CX180 shares this seal with a long list of pumps. These ones have their own seal page: AstralPool CTX, AstralPool CX240, AstralPool CX280, Filtermaster SB20, Filtermaster SB30, Onga Leisuretime LTP1100, Onga Pantera PPP750, Onga Pantera PPP1100 and Onga Pantera PPP1500.
It is also listed for pumps without a page of their own, including the AstralPool BX, CX, E-Series and TX, Poolrite Cougar, Enduro and Quietline, Filtermaster FM and FX Series, Onga JJ1, JJ600, OJ700 and OJ800, Spa-Quip Magnum, Maxiflo and Monster, Sta-Rite Max-E-Pro and Waterco Charger. If you run more than one of these, one seal type covers them.
Signs the AstralPool CX180 seal has failed
- Drips or a damp patch where the pump body meets the motor.
- White scale or a rust streak running down under the motor end.
- The pump struggling to hold prime, or drawing air at the motor end.
- A grinding or squealing motor after a long-running leak, which can mean water has reached the motor bearings.
Fitting notes for a 3/4″ shaft seal
A 3/4″ shaft measures about 19.05 mm, so a quick check with vernier callipers at the point where the seal sits will confirm the size. Replace both halves of the seal together: the spring-loaded rotating head and the stationary seat. Keep the polished faces clean and free of grease, use a little water or soapy water on the rubber parts to ease them into place, and press the seat in evenly. Never run the pump dry after fitting, as the faces rely on water for lubrication and cooling and can overheat and crack if run dry.
Need a capacitor as well? The CX180 seal and capacitor kit bundles both parts. Seals and kits to suit other AstralPool pumps are listed on our AstralPool service kits page.
Before you order
Check the old part before fitting: match the size of your old seal.