View Full Version : Fluidmaster flush valve

01-11-2006, 10:35 PM
I just used a Fluidmaster kit to replace everything in a toilet tank. The flush valve is the one with the adjustable flush. The flapper has a rotating flange piece that supposedly lets you adjust for bigger/smaller flushes.
Problem is, it doesn't flush right. You push the lever, the flapper pops up as normal, but doesn't stay up for any length of time. The moment you let go the lever, the flapper falls down and stops the water. For a normal firm push down and release of the lever, maybe 20-25% of the water in the tank goes out. Nothing looks abnormal or damaged. Rotating the adjustment piece to different settings makes no difference.
Can someone tell me if there is something peculiar about this flapper or how to figure out what's going on? Thanks


01-12-2006, 01:46 AM
I've had a similar problem with that particular flapper. There is a hard plastic plug in the bottom of the flapper which regulates how quickly it drops down. I have found that removing that plug eliminated the problem I was having.

01-12-2006, 04:54 AM
I have never had any success with the adjustable flapper.

01-12-2006, 05:38 AM
I've seen that one too. Try a Korkey flapper. I like the red one.

Bob NH
01-12-2006, 05:53 AM
I found that the 1.6 Gallons per flush toilets typically have tanks that contain about 3.5 gallons, and they are designed to only dump about half of the water. I measured the tank volume on a new Eljer and on my American Standard 1.6 GPF.

My Am Std came with a little float on the chain above the flapper that controlled when the flapper dropped. By moving the float down against the flapper, I got a full flush.

On the Eljer, there is no float or apparent adjustment, but you can get a full flush by holding down the lever.

You might get some improvement if you can shorten the flapper lift chain so there is no slack in it. Most of the flapper systems have some buoyancy or other device that keeps them open until the proper amount of water is discharged. The initial rise of the flapper has to be enough so the flow doesn't slam it down. It should float down with the water.

01-12-2006, 12:54 PM
Bob, this is not a 1.6 gal toilet. The Fluidmaster is a complete kit that replaces everything in the tank, so it doesn't depend on any existing parts or on the tank type. The flapper chain has almost no slack.

I am familiar with all the delay devices from buoys to over-center fill-and-drain, etc. This flush valve has no such supplementary device and works only on its own buoyancy.

It baffles me that this thing just plain does not work. It's hard to imagine them selling something that is inherently incapable of working. As I said, there is no apparent defect or damage to any parts. I'm trying to talk to someone at Fluidmaster, but so far no luck.

Thanks to all.

01-12-2006, 07:53 PM

I finally got somebody at Fluidmaster on the phone. Seemed knowledgeable and walked me through various tests while on the phone. Still could not find anything wrong. Said they would send me a new one.

So I took the flapper off the hinge pins and out, disassembled it, flexed, kneaded and played with every part. Nothing wrong. Put it back together and now works better. Still not a full flush at max setting but 80% flush.

Conclusion: poorly designed and made part. Perhaps too stiff or somehow needs loosening up by excessive handling. Advice: not good, don't buy.