My toilet is slow filling (10-15 minutes) and makes a hissing sound. I've taken it apart and cleaned the rubber diaphram (it wasn't dirty anyway). The water is coming out of #1 (the diaphram end).

There's a plastic top (#2) connected to the top of the valve assembly. I don't know what it is or what it does. It's got 4 holes in the front (#2) and a tube that goes down into the tank (#3).

What is this called? It doesn't seem to do anything - I can remove the plastic top (#2) and nothing changes; no water comes out of the top.
What does it do? How does it work?
Is water supposed to come out of #1 (the diaphram end) or #3 (the tube end)?

http://img232.imageshack.us/img232/4560/toiletvalvetp5.jpg

Thanks. :)

Loosen number four. Remove top half of fill valve and look for obstruction in top half. Where do you live, never seen a fill valve like that. I suspect that water is suppose to come out holes and be directed to overflow pipe to refill bowl.

Where is the small tube that runs from the ball cock to the overflow tube? This ballcock looks like it fills the tank through the tube but has no prevision for filling the bowl. You have two standard types of ballcocks, (see images), If this were my call I'd change out to one of them. Good luck, Tom

The tank should fill via #3.
#2 (the 4 hole thing) acts as an overflow and a vent.

The water that's coming out of #1, should go down #4. That helps fill the bowl.

Obstruction in #1, defecive #1 or obstruction in #4 is my best guess.

Thanks for the replies. :)

The photo was the nearest match I could find. I've now taken a photo of the real thing (with the arm and float removed).

http://img155.imageshack.us/img155/8087/mytoiletjo0.jpg

I've taken a photo of the diaphram (front and back). When the diaphram is removed the water pours out, so I'm guessing something is wrong with it.

Could it be that it is the wrong type or in the wrong way around? When I flipped it over I couldn't get the washer back on because the pin was pressing against the arm.

It used to work OK, but a couple of plumbers have had a go at it, and had trouble finding the right parts because it is a 1990 model.
:eek:

Plop, For less then 10 bucks you could replace that orphan and be out from under.
KISS, Explain to me how a flow directed by #4 to the tank will help fill the bowl. Regards, tom

True, but I live in the United Kingdom where consumers get ripped off and it costs more like £20 ($40). I'm replacing the bathroom suite soon anyway so not to worry. ;) by the way, the diaphram was on back to front, but it still doesn't work that well.

Speedball:

#4 is the tube going into the tank. It's not the coupling.

In the conventional setup, the little hose goes down the overflow tube. In your picture that #5.

So we need water to go down the overflow tube to fill the bowl. Right?

We know how it get's their in your picture?

We can only guess that it has to get down that tube internally through #1 is the poster's picture. That diaphram valve has to close off two water flows. The major one: down the big tube #3 and into the tank and the smaller volume, down the overflow #4 directly into the bowl.

The toilet bowl fill from two mechanisms: It gets a some from the rim flush and the makeup through the overflow tube.

Thus things that will cause a low water level are:
1. A toilet crack
2. Stopped rim holes
3. No water down overflow (e.g. tube not in hole)
4. A blocked overflow tube
5. Tank level not correct
6. Vent problems - water level decreases because of pressure changes (sucked out)

Some don't seem to apply in this case. 1,2,3,4,and 5 could.

Agree?

How does the water get down the overflow tube in the poster's set up?

EDITS: 4/1/08 , #6, Not apply

Looking at the new picture with the diaphram removed. I'm guessing that water passes through the small middle passage. A large amount fills the tank. There has to be a very small passage, say 4mm or so to the overflow tube #3. Guessing it's blocked.

If the diaphram was replaced, a bad diaphram can provide material to block the hole. I does on carburators. I had to rebuild mine because the secondary accelerator pump diaphram deteriorated and a piece git sucked into an internal carb passage. Compressed air had to be used to remove it.

Water flows up, through #1, #2, and down #3

Depending on how tight I put the float arm and washer back on (note that it pushes on the diaphram), I get one of two possible outcomes:

1. the water fills quickly (as it should do), BUT the valve does not shut off, so it overflows.
OR
2. the water fills slowly, AND the valve does shut off (as it should do)

It's really annoying as it's so close to being fixed.
:(

Is it possible that a spring is missing on the diaphram?

Replace the diaphram. Since the water supply isn't blocked or restricted it has to be the defective part, even if it looks all right to you. It certainly should be a replaceable part.

Thanks for all your help. I've decided to replace the bathroom suite within the next month, so I'll live with the problem until then.