Tank leaks into the bowl. Believe it is the gasket under the flapper/fill tube assembly. How do I correct this?

Hello David McInnis,

There are Three basic opportunities for leaks from the classic TOILET TANK DESIGN (separate BASE & top-tank)... around the FLAPPER VALVE alone... Typically the flapper valve & two hold-down screws. These CANNOT be repaired without removing the entire tank. GREAT CARE should be used to not FRACTURE
the mated surfaces by OVER-TIGHTENING.

This is a great time to FRESHEN UP all the
Perishable gaskets & seals... and while I NEVER advocate using any ABRASIVES on gloss finishes... Pumas stone seems to be the FINAL TOUCH in a total renewal
(to REMOVE the built up (very unsightly
TOILET BOWL RING...

Amazon com toilet bowl pumice stone

ADDITIONAL PARTS:
- Water fitting to FILL VALVE (compression fitting).
- FILL VALVE through tank (gaskets)
- Flapper Valve base, gaskets & bowl interface ring

TO Make sure all the surfaces are clean an firmly
positioned and it is not LEAKING anywhere... place
clean dry paper on the floor behind the bowl
(under the tank).

EACH/EVERY drop will leave a mark...
Do NOT over-tighten any fittings!!!

If the WALL VALVE is less than NIMBLE... also a great opportunity to UPGRADE TO A QUARTER TURN
BALL VALVE... A little shopping will find you EXACT VALVE CONFIGURATION...

Hope this helps.

LASCO 04 3809 Toilet Tank To Bowl Bolt Kit Brass Bolts with Washers Hex...

Fluidmaster 6106 2 3 4 Inch Tank to Bowl with Three Bolts and Gasket...

BrassCraft G2CR19X C1 1 2 in NOM Comp Inlet 3 8 in OD Compression Outlet...

Kohler 1068031 Fill Valve Flush Valves Amazon com

if the water keeps flowing then try replacing the flapper if it still flows then the fill tube gasket or tank to bowl gasket need to be replaced.

There are only a coulple of places that the toilet could leak or, overflow and give you this problem. When you replaced the flapper valve, did it have an extra piece of rugger on it? Universal flappers have a round piece on them that are designed to fit over the overflow tube. If you flapper had this piece and you don't have need for it, you need to cut that out, if the flapper "hooks" to the overflow assembly. Leaving that piec on can contort the shape of the flapper and make it so it won't seal. If you are noticing constant movement(slight swirl) in the bowl, make sure the back tank is not constantly overflowing into overflow tube. If this is the case, your water level is too high. You will either need to adjust the water level and/or replace the fill valve. If you can hear the toilet running or leaking, push down on the flapper, if it stops, you have a problem with the flapper and/or the chain adjustment. When you install the flapper, you have ton make sure the chain is long enough to let the flapper fall and seal but, not so long that it can tangle or get between the the flapper and it's seal below it.

Flapper or flush valve needs servicing
First try cleaning minderal deposits from around the valve seat. This can keep the flapper valve from sealing properly and allow water to seap into the bowl. First turn of the water and flush the toilet to empty the bowl. You can unhook the flapper valve to get it out of the way. Using emery cloth scrub the inside of the valve seat to remove the mineral deposits. Next coat the valve seat with petroleum jelly to help the flapper valve make a tight seal. Replace the flapper valve, turn on the water and check to see if the water still leaks.
If the flapper valve is old it may be deformed. In this case you will need to replace it. You can unhook the valve and remove the lift chain from the valve. Be sure to purchase a similar size replacement valve.
If the valve seat is damaged you will need to replace the entire flush-valve assembly. You will need to remove the tank to do this. Be certain to turn off the water supply and flush the tank to drain it. You might also want to place newspaper and towels on the floor to soak up any water that may leak out. Using and adjustable wrench loosen the nuts at the supply tube and push the tube aside. Next, use a flat-head screwdriver to hold the bolts inside the tank still while using an adjustable wrench to loosen the nut on the bottom of the tank. You will then be able to lift the tank off of the bowl. Lay the tank on the newspapers or towels.
To replace the flush-valve assembly first remove the old one by unscrewing the locknut on the bottom of the tank. Use a hacksaw to cut the new overflow pipe to 1/2 ince below the tank top. Put plumber's putty on the washer at the base of the flush-valve assembly and push the assembly against the tank opening, removing any excess putty. Use a monkey wrench to tighten the locknut. Replace the gasket over the locknut and replace the tank on the bowl and reassemble them.
g and adjustable wrench loosen the nuts at the supply tube and push the tube aside. Next, use a flat-head screwdriver to hold the bolts inside the tank still while using an adjustable wrench to loosen the nut on the bottom of the tank. You will then be able to lift the tank off of the bowl. Lay the tank on the newspapers or towels.
To replace the flush-valve assembly first remove the old one by unscrewing the locknut on the bottom of the tank. Use a hacksaw to cut the new overflow pipe to 1/2 ince below the tank top. Put plumber's putty on the washer at the base of the flush-valve assembly and push the assembly against the tank opening, removing any excess putty. Use a monkey wrench to tighten the locknut. Replace the gasket over the locknut and replace the tank on the bowl and reassemble them.

When the tank is full and leaking into the bowl reach in and put slight pressure on the flapper and if the leak stops then you may have the wrong flapper or the flapper is not installed properly. If that is not the case then make sure the flush valve seat is not cracked or that the surface is not warped.

fill valve not shutting off water running over overflow tube set or replace fill valve flapper valve leaking replace flapper valve cracked and leaking flush valve assembly replace

need to replace the "flapper"
an easy way to check to see if is leaking is to put a little red food coloring into the tank just above the flapper, wait a couple of minutes and if the red is showing in the bowl, the flapper is leaking.

if the flapper is not leaking...
there should be a small tube that is located in the top of the overflow. pull that off and see if water is coming out, if it is, then your fill valve is leaking and needs to be replaced.

As long as there is no water leaking from the tank to bowl connection, you are OK. You would know if it was leaking here, because you would have water dripping out onto the floor.

Verify that the water level in your tank is below the top of your new flush valve's overflow tube. If the water level comes to the top, it will overflow into the toilet bowl. This can be easily fixed with an adjustment to the fill valve.

If the water is not overflowing into this tube, then the only way you can lose water is through the flapper. You said you changed the flush valve, which would have come with a new flapper attached to it, but maybe buy a new flapper and see what happens???

You will need to replace or repair with new gaskets your flush valve mechanism. "To do that you need to take the tank apart from the bowl. Have new toilet bolts and flush valve or flush valve gaskets at the ready when you take the tank off. (you will also have to unhook the fill valve when you take the tank off.) Another possibility would be a cracked tank that is causing the leak in that area but that is rare.

Yes. You will have to remove your tank from the bowl to replace the defective fill stack(the tube thing your flapper is attached to) it is not as hard as it seems.First remove water supply tube.Then remove the through the tank bolts. should be two of them. Lift off and turn tank upside down. remove spud gasket. Unscrew old stack. You should be able to get a universal kit to work with your tank and should come with all new parts including new flapper and spud gasket. You will need new through the tank bolts and note the sequence of assembly to get water tight seal on tank. Hope this helps