# Fluidmaster 400A



## John Valdes (Apr 14, 2010)

Is there any further adjustment of Fluidmaster 400A? I bought one and its to sensitive. The slightest movement of the bowl (sitting down) will actuate the valve for less than one second.
Also does it occasionally by itself. Real fast and quick.

The hose has been trimmed short so it does not go below the water line.
The water level is low as I have a low flow tank. 1.8 Gallons. The valve is as far down as it can go so the lid will not hit it.
The flapper has not been replaced. But I did remove it, check it good and cleaned it.

I have read all of Fluidmasters instructions and have *done everything accept use the the little hose holder*. My fill tube has its own little holder located inside the tube.

Any suggestions.


----------



## rex (Jul 2, 2007)

Try another one.


----------



## John Valdes (Apr 14, 2010)

Its brand new. I did get a contractor pack (3).
Seems I replaced it for this same reason? 
Maybe it is the flapper letting water out.

You would think it could be adjusted a little bit.


----------



## rex (Jul 2, 2007)

It can be adjusted, thought I read you did do that.

Put some dye (food coloring) in the tank once its shut off to see if the flapper is leaking.


----------



## DuMass (Feb 6, 2008)

So with the valve being set all the way down for the tank lid clearance, is the critical ring on it still 1" above the top of fill tube on the flush valve? If not, I'm wondering if maybe that clearance might be needed to act like a buffer to keep the valve from quickly opening and closing when the water in the tank ripples.


----------



## John Valdes (Apr 14, 2010)

rex said:


> It can be adjusted, thought I read you did do that.
> 
> Put some dye (food coloring) in the tank once its shut off to see if the flapper is leaking.


I will mark it with a pencil as I have no dye. Mark the water level.



DuMass said:


> So with the valve being set all the way down for the tank lid clearance, is the critical ring on it still 1" above the top of fill tube on the flush valve? If not, I'm wondering if maybe that clearance might be needed to act like a buffer to keep the valve from quickly opening and closing when the water in the tank ripples.


I just pulled the hose all the way to the top of the fill tube. It was about 1" or more above the water level.

I know the first answer was to replace it. What I might have said if I was plumber. But this problem has followed two (2) valves. The original one and this new one.

I see a hole on the top of the float. I am thinking some weight on the float will hold it down and make it harder to act up? Or this hole is there for a reason. Like to add water to it??????? Make it heavier?

Just a thought. I am going to put a quarter on top of the float and see, if the little hose is not the problem.
I will wait and see if bringing the fill tube up some more works first.

Thanks Gentlemen and everyone else. :laughing:


----------



## MarkJames (Nov 25, 2012)

When tank is full, final water level should be between 1"-to 1/4" below the top edge of the overflow tube.

The hose should be clipped to the top of the overflow tube so the end remains above the water line (when tank is full). Note, some will disagree with me on this, but yes, it can cause the valve to leak if you just push the tube down in there. 

The float operates the shut-off lever. You want the float to raise the lever fully in order to close the valve. Maybe it's not raising the lever fully. You can adjust it with the vertical thumb screw/threaded rod. It has a phillips head you might see on top, but you can just use your fingers and turn it a bit. Turn it counterclockwise to lower the float, or reverse to raise the float. You probably need to lower the float in your case.

Finally, if the toilet is loose or rocking, use some shims near the front (either side, as necessary) to snug it up. They make plastic toilet shims or you can use composite shims and trim them.

-------

Quick edit: Check this first: When tank is full, are you able to lift the float any further? If yes, float is set too high. Adjust as I mentioned above with the thumb screw.

If that doesn't do it, or you run out of room to adjust the float enough, then your valve is too high. You can remove it, twist it shorter, then retighten. Or, if you want a short-cut, you can turn off the water, reach down for the grey lock ring, push it downward to release it, then push the valve down a bit (eg. 1/2" or so) to shorten the height, then grab that grey ring and pull it back up to lock in place. MAKE SURE it locks back in place and you can't adjust the height anymore. Turn water back on. Adjust as necessary. (BTW, I do this adjustment without shutting off the water - IF you do this, you have to hold the valve down with your other hand or the water pressure will pop it right off until you snap the lock ring back in place.)


----------



## John Valdes (Apr 14, 2010)

MarkJames said:


> When tank is full, final water level should be between 1"-to 1/4" below the top edge of the overflow tube.
> 
> The hose should be clipped to the top of the overflow tube so the end remains above the water line (when tank is full). Note, some will disagree with me on this, but yes, it can cause the valve to leak if you just push the tube down in there.
> 
> ...


Thanks Mark,
Yes the little hose was high enough above the water line and the water was a couple inches below the top of the fill tube.

I did install the clip that holds the hose above the fill tube.
I also adjusted the actual valve height as you mentioned. It must go all the way down for the lid to clear.
I used the lock ring. I did not pull it out.

My mark on the water line did indeed show water was leaking from the tank. I bought a flapper yesterday and the toilet has not made a sound since I did those two (2) things.

One more question please.
Can the flapper be adjusted to fall exactly square on the hole?
It wants to drop a bit to the left. The fill tube and flapper holder are lined up perfectly, but could use some adjustment there too.

Thanks very much................John


----------



## MarkJames (Nov 25, 2012)

John Valdes said:


> One more question please.
> Can the flapper be adjusted to fall exactly square on the hole?
> It wants to drop a bit to the left. The fill tube and flapper holder are lined up perfectly, but could use some adjustment there too.
> 
> Thanks very much................John


Sorry I didn't see this earlier. Try hooking the flapper chain to a different spot (hole) on the flush arm.


----------

