Oli 74 Cistern Outlet Valve

Is this the right valve for your cistern? To confirm, remove your flush plate and look at the back inside wall of the cistern tank. It should be embossed with “OLI 74”.

Important Note: This is the new rigid plastic version. It replaces the discontinued older model that featured a flexible black rubber tube in the center. While the new version is more durable, it requires the “unlock” mechanism (see video) to sit correctly in the cistern.

Why this Universal Valve is the Correct Fix: The original OLI 74 valves were prone to failure in the flexible center. This updated OLI 74 Universal Valve is designed to replace four different previous iterations.

Expert Installation Tip: Because this new version is rigid (unlike the old flexible rubber version), it can be slightly harder to maneuver back into the cistern.

The Unlock Feature: Use the built-in unlock mechanism to compress or adjust the valve for a perfect fit.

The Seal: This valve uses the standard Oli seal.

Still Leaking into the Bowl? If you have replaced the valve and the seal, but water is still dripping into the pan, the Cistern Guide may be the culprit. Over time, plastic cistern tanks can slightly warp. If the guide (the “basket” the valve sits in) isn’t perfectly flush, the valve cannot create a watertight seal.

Recommendation: If your cistern is over 10 years old, we highly recommend replacing the OLI 74 Valve Guide at the same time as the valve.

Q: My old valve has a black rubber tube, but this one is all plastic. Will it fit?
A: Yes. The black rubber version is discontinued. This rigid plastic model is the official replacement. It is designed to be universal and replaces 4 older OLI valve styles.

Q: Why is it harder to install than the old one?
A: The old rubber version could bend around internal components. The new version uses an “unlock and slide” mechanism to fit into the same space. Please watch our installation video on this page for a step-by-step guide.

Q: Is this for a “ghost flush” or a full leak?
A: If you have a slow drip, you might only need a new washer. However, if the flush mechanism is sticky or there is a significant flow of water into the bowl, you should replace the entire OLI 74 assembly.