Pedrollo PKM90 Mechanical Seal

The Pedrollo PKM90 uses a mechanical seal for a 12 mm shaft with carbon / ceramic faces. This aftermarket seal suits the PKM90 peripheral pump and is the same seal used on the Pedrollo PKM60, PKM65 and PKM70. Before fitting, measure the shaft where the old seal sits and compare your old seal with the new one face to face.

Pedrollo PKM90 seal: 12 mm shaft, carbon / ceramic faces

This is a two-piece mechanical seal sized for a 12 mm shaft. A spring presses the rotating face, which turns with the shaft just behind the impeller, against a stationary seat held in the pump casing. One face is carbon and the other ceramic. A thin film of water between the two lapped faces lubricates them, while the seal stops water getting through to the motor side.

It is also sold on its own as our 12 mm jet and peripheral pump seal, if you are matching by size rather than by model.

Other pumps that take the PKM90 seal

In the Pedrollo PKM range the same seal fits the Pedrollo PKM60 and Pedrollo PKM65, plus the PKM70. Other Pedrollo pumps that use it include the JCR1A, JCR1B, JSW1A and JSW1C. Outside Pedrollo it suits the Onga Jetinox, JS120, JS130, TF30 and SMH Series, the DAB Nova 41 and KP30/16-6, the Pentax CM6, PM and PE, the Ebara JES and JESX, the Calpeda NGX, the Davies PL/OD/PM Series and the Saer CMP, KF0, KF1, KF6, M50 and Mini Matic.

Seals and kits for other Pedrollo pumps are listed under Pedrollo service kits.

Signs the PKM90 seal is leaking

Seals tend to start with a small weep and get steadily worse, so it pays to catch them early. Running the pump dry, for example after it has lost prime, is a common way to damage the faces, so check for a leak after any dry run.

• Drips or a wet line between the pump casing and the motor.
• White scale, a rust stain or a damp patch below the motor end.
• The pump cutting in by itself with every tap closed.

Fitting a new seal to the PKM90

Turn the power off at the switchboard before opening the pump. Handle the new faces by their edges and keep them spotless, because a fingerprint or speck of grit can cause a leak. Lubricate the rubber parts with clean water or a drop of dishwashing liquid, never oil or grease. Check the shaft is smooth where the seal runs, and prime the pump fully before switching on so the new faces never run dry.

Before you order

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

Capacitor details for this pump: Pedrollo PKM90 capacitor guide.

What seal fits a Pedrollo PKM90?

The Pedrollo PKM90 takes a mechanical seal for a 12 mm shaft with carbon / ceramic faces. This aftermarket seal is made to suit it; check your old seal's size before fitting.

What shaft size is the Pedrollo PKM90 seal?

The Pedrollo PKM90 seal suits a 12 mm shaft. Measure the shaft where the old seal sat to confirm before you fit it.

Does the Pedrollo PKM60 or PKM65 use the same seal as the PKM90?

Yes. The Pedrollo PKM60, PKM65 and PKM70 use the same 12 mm carbon / ceramic seal as the PKM90.

Can I replace just the seal on a PKM90?

Yes. The seal on a Pedrollo PKM90 can be changed on its own. If the motor bearings are noisy too, the PKM90 service kit adds both bearings and the capacitor.

Why is my Pedrollo PKM90 leaking between the pump and motor?

Water at that joint on a Pedrollo PKM90 usually means the mechanical seal faces are worn or cracked. Replace the seal before the water reaches the motor bearings.

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.