Wilco Outlet Valve Washer | Genuine Replacement Seal

Stop the “Black Grit” Leak

If you have touched your old Wilco washer and ended up with black residue on your hands, the seal has failed. Older black rubber washers were prone to osmotic swelling and disintegration due to water chemicals.

The New Clear Silicone Standard: This genuine Wilco replacement is now manufactured from a high-grade clear silicone.

• Chemical Resistant: Will not swell or perish like the old black rubber versions.

• Perfect Seat: While generic washers often look similar, they rarely have the exact shore hardness (flexibility) required to seal under the low-pressure gravity of a cistern.

• Universal Fit: This single washer fits all three Wilco outlet valve models currently stocked on our website.

3. Diagnostic Checklist: Is it time to replace?

If your Wilco cistern is showing these signs, this $10–$15 part is likely the fix:

• The Ghost Flush: The cistern refills itself periodically even when no one has used it.

• The Constant Trickle: A visible ripple of water running down the back of the toilet bowl after the flush is complete.

• The Visual Test: If the washer looks “wavy,” swollen, or leaves a black stain on your fingers, it has lost its seal.

• The 5-Year Rule: We recommend replacing these seals every 5 years as preventative maintenance to avoid water wastage and high utility bills.

The Spare Parts Specialist

Don’t waste time with “universal” hardware store kits that don’t quite fit. We specialize in genuine Wilco components:

• Immediate Dispatch: These are small but urgent parts. We prioritize fast shipping to stop your leak as quickly as possible.

• Mascot Pickup: Located in Sydney? Swing by our Mascot warehouse for a 1-minute “over-the-counter” pickup. | Expert Support: Not sure if it’s the washer or the whole valve? Bring your old valve into the showroom, and we will test the fit for you.

• Q: My old washer is black, but this one is clear. Is it definitely the right part?

  • A: Yes. Wilco upgraded the material to clear silicone because the old black rubber was prone to breaking down and leaving “black grit” in the system. The clear version is more durable and chemical-resistant.

• Q: Can I just flip the old washer over to stop the leak?

  • A: This is a temporary “Sunday afternoon” fix. Once the material starts to swell or perish, flipping it will only work for a few days. Replacing it with the genuine silicone seal is the only permanent solution.

• Q: Is this easy to install?

  • A: Yes. Most Wilco valves allow you to unclip the center canister, slide the old washer off, and “button-hole” the new one on without removing the entire cistern.

This Genuine Seal fits the following 3 Wilco Valves:

1. Wilco Slim Outlet Valve – The tallest of the valves. The toilet lid when lifted will not touch the push plate

2. Wilco Mid Height Outlet Valve – Found in the majority of Wilco toilets and is the most common

3. Wilco Low-Profile Outlet Valve – Designed for compact toilets, and the only one where the button can be mounted on a bench.

Specialist Tip: If you are unsure which valve you have, check the color of the plastic. If it’s a Wilco housing, this clear silicone washer is guaranteed to be the correct internal seal.