My toilet keeps leaking water and then fill ups on its own. Where could the leak be how do I fix it? Also I have to hold down the flush lever awhile for the toilet to completely flush. Can this be fixed ? What supplies do I need?

hi Patricia.
Overview Toilets haven't changed much in the last 80 years. After a flush, water still fills a tank, lifting a float that shuts off the water when it reaches a certain level. A lever still opens a flapper to cause the flush, falling back into place when the water level drops. So it's no surprise (nor any consolation) that we face the same flush problems today that our grandparents did. Sometimes the flush is too wimpy, sometimes the toilet keeps running, and sometimes the bowl doesn't refill.
Our ace plumbing consultant has a simple four-step strategy to solve 95 percent of these problems. You can complete the first three steps in five minutes. That'll solve most problems. The fourth step is usually easy too, but not always. More on this later. These steps work for most toilets but not for pressure-assist models.
Check the fill tube

Overflow tube problem

Push the fill tube firmly onto the fill valve. Make sure the fill tube sends water into the overflow tube.Remove the tank lid and find the fill tube. It's a small flexible tube that runs from the fill valve to the overflow tube. While the tank refills, this tube squirts enough water down the overflow tube to refill the bowl after the completed flush. If this tube falls off or the water stream misses the overflow tube, the bowl won't fill and your next flush will be wimpy (that is, won't develop a strong siphon). Reattach the fill tube and make sure it perches about 1 in. above the rim of the overflow tube. Flush the toilet and watch the water stream to make sure it goes down the overflow tube.
Adjust the fill height

Check the float

Adjust the float to set the water level. Pinch the clip and slide the float up or down on the rod. Keep adjusting the float until the water shuts off at the proper level.The water level in the tank is controlled by an adjustable float. A float that's set too low produces a weak flush; if it's set too high, water spills into the overflow tube and the fill valve won't shut off. The toilet keeps running. Look for the fill level mark on the inside back of the tank and mark it on the overflow tube so you can see it more easily. If you can't find it, measure down about 1 in. on the overflow tube and make a mark. Then flush the toilet and see if the water reaches and stops at that mark. If not and the toilet keeps running, adjust the float up or down. If you have an old toilet, you'll have to bend the brass rod that connects to the float ball to make adjustments. But with newer toilets you usually turn a screw or slide a clip along a rod. Flush the toilet after each adjustment.
Also make sure that the water level is at least an inch below the C-L (critical level) marked on the fill valve. You can adjust the height of many valves to raise or lower the C-L.
Occasionally the fill valve simply won't shut off, which means that it's defective. If so, turn the water supply off at the shutoff under the tank. Buy a replacement valve (sold at hardware stores and home centers). You don't have to match the old one; many, like the one shown, fit most toilets. It's a 15-minute change-out.
Adjust the flush handle/flapper chain

Flapper chain fix

Adjust the chain to leave a little slack with the flapper closed. Then cut off the excess, leaving about an inch.A chain that's too short or tangled won't allow the flapper to close and water will continue to leak into the bowl. This causes the fill valve to cycle on and off to refill the tank. A chain that's too long, or a flush rod that hits the the tank lid, won't open the flapper wide enough to stay open for the full flush. You'll find yourself having to hold the lever to complete a good flush.
To avoid these problems, adjust the linkage in the chain to leave only a slight bit of slack when closed. Cut the chain at the rod to leave only about an inch extra to reduce the potential for tangles. Then put the tank lid back on and make sure the flush rod doesn't strike the lid when you press the lever. If it does, bend it down slightly and readjust the chain.
Replace the flapper

Change the flapper

Unsnap the old flapper and take it with you to the store to find an exact replacement. In addition to the closest replacement, pick up a "universal" type.If you've completed the first three steps and your toilet keeps running, chances are you have a worn-out flapper. Turn off the water, remove the old flapper and take it to the store to find an exact replacement. (Hardware stores often carry a wide variety.) Most flappers snap over ears on the overflow tube. Others have a ring that slips over the tube.
Now here's the catch. You may not find an exact match. The range of flapper styles has mushroomed over the last 15 years, and you may find 15 to 20 flapper options on the store shelf. Some packages include specific brand and model information (so note yours before you leave home). Others have a "universal" label. If you can't find an exact replacement, try the closest one and pick up a universal type as well. They're cheap, and the extra one just might save you a second trip to the store! (Avoid the "adjustable" types unless you're replacing an adjustable one.)
Install the new flapper and make sure it opens and closes freely. Then test it. If the toilet keeps running or runs intermittently, you're not getting a good seal. Try a different flapper if the toilet won't stop running.
If you just can't find a flapper that seals, consider replacing the entire overflow tube/flapper. On most toilets (two-piece), this means removing the tank. It's not difficult and you don't need special tools. It'll take you about an hour, and you'll avoid that expensive plumber service call.
if you go to this link it will show you step by step on how to fix it. How to Stop Running Toilet Family Handyman

Hi Nathan:
If you lift the tank lid off and flush the toilet you will see that a flapper valve lifts to let the water drain from the tank. The flapper valves are designed to stay in the closed position when the tank fills, but to float when the tank is flushed.
The problem will probably be that the flapper valve no longer floats due to saturation with water, or a leak that has allowed water inside the float.
The fix is to replace the float valve. Parts are available at most hardware and plumbing supply stores.
Cheers

The bowl is cracked and is leaking down the drain. You will have to replace it. It may have cracked if the bowl hold-down bolts were overtightened, or the bowl was not able to sit flush (pardon the pun) on the floor. If the bowl rocks when it is first installed, instead of tightening the hold-down bolts, use a couple of tapered shims under the edge of it, then caulk to fill the gap and hide the shims.
Good luck.

Sounds like the flapper is leaking water out of the tank. The flapper is the rubber valve that comes up and down every time you pull the flush lever. It is located in the tank at the bottom in the center. Very cheap part to replace.. Just turn the water off to the stool, take the top of the tank off, hold the flush lever down until all the water is out of the tank, reach in to the tank, disconnect the flush chain from the flapper, and disconnect the flapper arms holding to the stem. You can buy a flapper at any hardware store even at wal mart. Hope this helps.

The ball float follows the tank water level, and repeated cycles of the float dropping and opening the fill valve would likely reflect a leak in the flush valve. You could try adjusting the float arm downward so that it will respond to a lower water level. Try turning off the supply valve, flushing it and listen for water leaking past the flush valve after it closes. If it does, replace the flapper or adjust the chain.

Check flapper seal and alignment, there must be leak-by there somewhere.Maybe a piece of debris at seal area. If chain or whatever is used to lift it when flushed, is not slack enough, that will also cause leak-by.

Lift the tank lid off, place it somewhere safe for a moment, and look at what happens: If you're talking about jiggling the handle to get the tank to start to fill with water, then it sounds like the chain or rope is out of adjustment. It can't be TOO TIGHT or the water will leak past your flapper (will cause your dripping noise, tank water level will leak down, causing constant refills), and it cant be TOO LOOSE or the toilet won't flush correctly. Since you didn't mention trouble flushing the toilet, I think that it may be a little too TIGHT. When you jiggle the flush lever-it is supposed to pull a chain or cable to open the flapper at the bottom of the tank. Flush the tank and watch what happens-all the way through to refilling the tank with water and shutting off the water refill valve-Does the flapper get stuck on the chain or something? It is supposed to fall back down to allow the tank to refill after flushing out your toilet. Does the chain look very loose? The dripping sound you described indicates that the flapper is not sealing 100%. The flapper is very easy to replace, you just have to get the adjustment set for when you flush the toilet how sensitive you need it. You amy have to play with it a little bit before you get the adjustment correct.

Hope this helps!

it sounds like your flapper (flush valve) is leaking.
if you here your toilet filling up and no one flushed.
push down on flapper to see if you here the water stop leaking out. if so replace flapper. even if toilet is 1yr or less old. could be a bad flapper. hope this helps. duane :)

You need to replace the tank flapper valve gasket.