A cistern that won't stop trickling into the pan, a weak flush or a button that needs holding down usually points to one part: the outlet valve. For a huge number of Caroma, Fowler and Stylus vitreous china (ceramic) cisterns, the replacement is the Caroma Quietflow 2 M5 Outlet Valve, part 750085 ($56.99). This guide covers what it fits, what it replaces and how to set it up so the flush matches the pan.
First, confirm it's the outlet valve
Two different faults both look like a “running toilet”:
- Outlet valve leaking: water seeps past the outlet seal into the pan. The water level in the cistern drops slowly and the inlet valve refills it every so often. A few drops of food colouring in the cistern (not the pan) will show up in the pan within 15–30 minutes without flushing.
- Inlet valve overfilling: the water level rises until it runs into the overflow. That's a fill valve or washer problem — see Cistern Won't Stop Running? Match the Right Washer and Bottom Entry vs Side Entry Inlet Valves.
Which suites the 750085 fits
Per Caroma's listing, the 750085 suits vitreous china cisterns on these suites:
- Caroma: Viceroy, Vintage, Vand, Sovereign Retro, Sovereign 2000, Sovereign, Regal II, Regal, Profile (integrated hand basin), Profile, Opal II, Opal, Milan, Leda, Harmony, Geo, Elba, Cube, Caravelle 2000, Altisse
- Fowler: Seido, Regent, Newport Cube, Newport, Consort
- Stylus: Venecia
It's for ceramic cisterns. Plastic link and connector cisterns and in-wall cisterns use different mechanisms — for example the Caroma Invisi Series II in-wall cistern takes the Invisi II 4.5/3L outlet valve assembly (237172), with the bridge assembly with bellows (237275) linking it to the wall buttons.
What it supersedes
The 750085 replaces three older outlet valves, so if you pull one of these out, this is the replacement:
| Old part | Description |
|---|---|
| 750080 | M5 outlet valve |
| 413295 | Duoflo Type 2 |
| 413296 | Duoflo Type 3 |
Setting the flush volume
The valve ships adjustable and can be set to 4.5/3L, 6/3L or 9/4.5L. Match it to the pan, not to what you'd like it to be — an older pan designed for 9/4.5L may not clear properly on 4.5/3L. Caroma gives three ways to get it right:
- Copy the setting from the old valve you're removing.
- Look up the toilet suite name in Caroma's Quick Reference Chart.
- Measure the existing flush and set the new valve to match.
Buttons and inlet valve
- Buttons: button platform extensions and forward/rear-of-centre button caps are included, so the valve lines up with the existing dual flush button position.
- Inlet valve: cisterns still fitted with the original square-style outlet valve may also need the rear entry inlet valve replaced. Caroma's recommended companion is the rear entry inlet valve kit 687257 (sold separately). For bottom-inlet cisterns, the Quietflow 2 Bottom Inlet Valve (687042) is the matching fill valve.
When a seal is enough
If the valve body is in good condition and the only fault is a slow leak past the seal, the Caroma M5 outlet valve seal kit (405889, 10-pack) is a cheaper fix — and a 10-pack on the van covers plenty of service calls. If the valve is old, brittle, or the flush itself is weak or inconsistent, replace the whole valve.
Frequently Asked Questions
What does the Caroma 750085 outlet valve replace?
It supersedes the older 750080 (M5), 413295 (Duoflo Type 2) and 413296 (Duoflo Type 3) outlet valves.
What flush volumes can the 750085 be set to?
4.5/3L, 6/3L or 9/4.5L. Set it to suit the pan — copy the old valve's setting, use Caroma's Quick Reference Chart, or measure the existing flush.
Does the 750085 fit plastic or in-wall cisterns?
No. It's for vitreous china (ceramic) cisterns on Caroma, Fowler and Stylus suites. In-wall cisterns like the Caroma Invisi II use their own outlet valve assembly.
How do I tell if the outlet valve is leaking?
Add food colouring to the cistern water and wait 15–30 minutes without flushing. If colour appears in the pan, water is getting past the outlet valve seal.