My toilet takes between 10 and 20 minutes to stop filling after it is flushed. Once it stops, it's fine. The tank actually fills up very quickly, but then it just keeps "filling" when the water is all the way at the water line. That is the confusing part--I can't tell why it runs for the extra 9 to 19 minutes and then reliably shuts off every time.

Here's a photo:



You can see the water still coming out of part A forcefully even though the tank is filled. The water valve leading to the toilet is open fully. I've wiggled part B and I can tell that it's already all the way at the top of its travel.

If it helps, this is the type of flap at the bottom. It seems to seat firmly:



Does anyone have any advice on this? It is the only toilet in my house, so I'm hesitant to work on it until I understand why it continues to run for so long after the tank is full, but it always stops eventually.

Thanks,
Greg

 

You are lucky it stops at all, not sure why it does. The water should be below the overflow tube, which in the pics its not. Adjust the float on the fill valve (B) so the water is below the top of the overflow.

 

The good news is it is an easy brand to fix and find replacement parts if needed.

The float may be adjusted improperly and may be the only problem. The other problem could be some dirt in the rubber seal of the valve.

First you want to see if the water stops fine if you just lift up on the float. If it does, adjust the float. To do this, use the spring clip on the stainless rod and try to slide it down, bringing the float down at the same time. If it is already all the way down, you will want to shut off the water and reach below the float. On the tube coming up from the bottom of the toilet, there is a gray plastic spacer, once that is pulled up, you can move the whole contraption up or down to accommodate different toilet heights. You will want to slide it down a click then push the plastic spacer/ locking ring back down also. Then make any final adjustments with the spring clip. The water should stop about 1/2" before going over to top of the overflow tube.

If the rubber seal is dirty or needs replacement in the valve, shut the water off and hold the float up as high as it will go. With your other hand, turn the plastic cap on top and it will come apart. remember how to re install the cap. Look inside and check for dirt. The seal for a fluidmaster valve is standard and you may want to just replace it. Easy job. I usually hold my hand over the hole where the water comes from and flush out the line by turning the water on for a few seconds. If you do not cover the top, you WILL wash your ceiling.

replace the parts and all should be well.

Here is the web page for the repairing the valve you have. the only difference is the newer style has a plastic rod instead of the metal rod and clip you have.
http://www.fluidmaster.com/pdfs/400a_instructions.pdf

 

Thanks, guys. I did try to lift the float, and the arm (where "B" is pointing in my photo) is solidly all the way at the top of its travel. So I think it's probably the seal. The mystery is why it ever stops "filling." It has always shut off eventually. Maybe there'll be a clue once I get in there. I'll keep you posted.

Greg

 

42 year old toilet!! Mark's description as how to clear the valve should clear it all up. If not, they are easy to replace.

 

Hi guys. I tried moving the metal clip down. No deal. It's hard to tell from the photos, but the float was already all the way underwater before. Now it's just farther underwater. So I guess it's time to check that seal. Someone else mentioned that the incoming water pressure might be too high to allow it to close. Does that make any sense? I guess I could just turn it down and see how that goes.

How can you tell the age of the toilet? I'm sure you're right--everything here is from the 1960s.

Thanks!

 

Right behind the fill valve molded in to the tank "1 18 67". Prob means Jan 18th, 1967.

Don't use the shutoff valve to try to adjust water pressure, it will adjust flow, but the pressure would still build up. Those valves are really designed to be all the way on or off anyway.

As Mark said, the seal under the cap is quick, cheap, and easy if it solves the problem. Might want to pick up a whole new fill valve at the same time just in case. You can always return it.

 

While you are at the store, pick up a sillcock gauge and check your house pressure from a hose bib on the outside of the house. It may need adjusting, for sure, but most likely isn't the culprit here.

 

Thanks, everyone. It was the seal in part B. Three-dollar fix! I appreciate all your help.

Greg

 

Mark wins again.....I was just having a bad response day...lol

 

Now let's not look at it that way...

Even though I am the best , Just kidding Beer 4U2