Davey - Silensor / SilensorPro Pump Casing O-Ring (Part 43784)

Davey – Silensor / SilensorPro Pump Casing O-Ring (Part 43784)

This is the genuine Davey pump casing O-ring (part number 43784, in the Silensor spare parts diagram) for the Davey Silensor and SilensorPro pool pump ranges. It forms the critical seal between the pump casing halves, preventing water leaks and maintaining the pressure integrity of the pump body. Replacing a worn or degraded casing O-ring is one of the most common and cost-effective Silensor service tasks.

Compatibility

This O-ring fits the full Davey Silensor and SilensorPro pump families, including SLS and SLL series models (e.g. SLS100, SLS200, SLL150, SLL200, SLL1200F, SLL2003F, SLL3003F, SLL4003F, SLL1503F, SLL400E, SLS100E, SLS150E, SLL150E) and SilensorPro variable-speed models (SP200BT, SP400BT). It is also included in the Davey Silensor seal kit. If you are unsure of your exact model, check the data label on the back of your pump.

When to Replace

The casing O-ring should be inspected whenever the pump is opened for servicing — for example during a bearing change, mechanical seal replacement, or impeller service. Signs that replacement is due include visible water leaking from the pump body joint, cracking or flattening of the rubber, or loss of prime due to air ingress at the casing. As a best practice, fitting a new O-ring every time the pump casing is separated ensures a reliable seal on reassembly.

Installation

Davey Silensor service tools 13810SP and 13810-1SP are required to remove the casing nuts safely during disassembly. No sealants, glues, or silicones are needed — the O-ring seals by compression alone. Ensure the O-ring groove is clean and free of debris before fitting the new seal, then reassemble and tighten the casing nut securely using the appropriate Davey spanner.