Davey Silensor SLS75 Mechanical Seal

The Davey Silensor SLS75 takes a mechanical shaft seal for a 5/8″ shaft (about 15.9 mm). Davey’s part number for it is 49771SP, and this CapacitorsNZ seal is an aftermarket replacement for 49771SP. The same seal suits the Silensor SLS100, SLS150 and SLL150 among others, plus the Davey HS50 and HS60. Compare it with your old seal before fitting.

Pumps that share the Davey Silensor SLS75 seal

This seal, which replaces Davey 49771SP in the Silensor SLS75, is also listed to suit these Davey models: Davey HS50, Davey HS60, Davey Silensor SLL150, Davey Silensor SLL200, Davey Silensor SLL300, Davey Silensor SLL400, Davey Silensor SLS100, Davey Silensor SLS150, Davey Silensor SLS200 and Davey Silensor SLS300.

It also suits the Davey HS60-08 and the Davey ProMaster, which don’t have their own listing pages. If you look after more than one of these pumps, the same seal is sold on its own as our 5/8″ seal for Davey HS50, HS60, Silensor and ProMaster pumps. Parts for other models are under Davey service kits.

How to spot a worn SLS75 seal

Change the seal as soon as you see a leak. Water that tracks along the shaft into the motor ruins the bearings, and that turns a seal job into a motor job.

• Water dripping or weeping from the gap between the pump housing and the motor.
• Crusty white deposits or a rust stain on the pad under the motor end.
• The pump struggling to hold prime even though the lid and unions are tight.
• A new squeal or grinding from the motor, which can mean water has already reached the bearings.

Fitting notes for the Silensor SLS75

Isolate the pump at the wall, close the valves and drain the pump body before you start. A mechanical seal comes in two halves: a stationary seat that presses into the pump housing, and a spring-loaded rotating half that slides onto the shaft behind the impeller. Always replace both halves together, never just one.

Keep the polished faces clean and free of fingerprints, wet the rubber parts with soapy water rather than grease so they slide home, and never run the pump dry once the new seal is in, as running dry can overheat and damage the seal faces. Measure the shaft where the seal sits to confirm it is 5/8″.

Before you order

Check the old part before fitting: match the size of your old seal.

Capacitor details for this pump: Davey Silensor SLS75 capacitor guide.

What seal fits a Davey Silensor SLS75?

The Davey Silensor SLS75 takes a mechanical seal for a 5/8″ shaft that replaces Davey 49771SP. The CapacitorsNZ seal to suit the Silensor SLS75 is an aftermarket replacement for that part, not a Davey-made seal.

What is the Davey part number for the Silensor SLS75 seal?

Davey's part number for the Silensor SLS75 mechanical seal is 49771SP. Quote that number when comparing seals.

Does the Silensor SLS100 use the same seal as the SLS75?

Yes. The Davey Silensor SLS100 and SLS75 both take the 5/8″ seal that replaces 49771SP, as do the Silensor SLS150, SLS200, SLS300, SLL150, SLL200, SLL300 and SLL400.

What shaft size is the Davey Silensor SLS75 seal?

The Silensor SLS75 seal suits a 5/8″ shaft, which is about 15.9 mm. Measure the shaft where the old seal sat if you want to double-check.

Can I replace just the seal on a Silensor SLS75?

Yes, the seal can be changed on its own. If the Silensor SLS75 is also slow to start, the SLS75 service kit adds the capacitor in the same job.

What if it doesn't fit?

If you're unsure, send us a photo of your old part and the pump's label before ordering.