Tank to Bowl Leak

[jw14]

Just installed a new Briggs Altima bowl and tank, and I've got a leak where the tank meets the bowl. Not sure if its the tank to bowl seal or the mounting bolts. I've tightened the connecting bolts about as far as I can, any more, and I'm afraid I'll crack the porcelain.

But here's where I have some concern. The tank does not sit flush on the bowl. The back to the bowl has two thin ridges (parallel to the wall behind the tank). The tank sits on top of these ridges. The connecting bolts go through a thin rubber washer, then through the tank, then there's a space of about 1/4 inch before the bolt goes through the bowl, then a metal washer, and finally the nut. Are those ridges on the back of the bowl common, and if so, can I expect to get a good seal there when the tank is not flush with the bowl (at the mounting holes)? Could that be the source of my leak? Any suggestions?

[LazyPup]

Your problem is common and there is a very simple solution.

Begin by obtaining two additional brass nuts, two flat rubber washers and two metal washers. (Some of the new tank to bowl bolt sets come with the extra nuts and washers.)

1.Turn the water off, drain the tank and remove the water supply line.
2.Remove the tank to bowl bolts.
3.Put a rubber washer under the head of the tank to bowl bolt.
4.Apply a bit of clear silicone sealer on both sides of the washer to seal it to the bolt and to the tank bottom.
5. Apply a bit of silicone sealer to one side of another rubber washer and slide it on the bolt until it is tight with the underside of the tank.
6. Slip a nut on the bolt and run it up tight against the bottom of the tank.
7.Repeat the process for the other tank to bowl bolt.
8.check the alignment of the tank to bowl donut gasket to insure it is completely covering the flush valve mounting nut and is tight against the underside of the bowl. (You could apply a light film of the clear silicone on both the upper and lower mating surfaces of the gasket.)
9. Carefully set the tank on the bowl to insure the donut gasket is properly aligned in the recessed receiver in the bowl.
10. Install a washer and nut on the tank to bowl bolts on the underside of the bowl flange and snug the nuts up to secure the tank to the bowl.
11. Re-attach the water supply line and turn the valve on.

(By installing a rubber washer and a nut on the underside of the tank it will insure a good seal between the bolts and the tank.)

[jw14]

Thanks very much.

I have got a real nice tight seal on the connecting bolts, but still had a small leak after installing the tank.

To test, I took off the tank, removed the donut gasket on the underside of the tank, and propped it up between two chairs. I then poured some water into the tank, and crawled under to take a peek. The area around the connecting bolts remains dry, but I've got some water leaking out between the flush valve nut (?), and the porcelain tank itself. (not through the flush valve, I didn't put enough water in to reach the bottom of the flapper). There is a thin rubber gasket on the inside of the tank.

Any suggestions?

By the way, this is a brand new bowl and tank.

[LazyPup]

Take the locknut off the bottom of the flush valve, and pull the flush vave out out the tank.

Thoroughly clean the ceramic, both inside and outside the tank in the area where the flush valve gasket meets the tank.

Put a light film of clear silicone sealant on the donut gasket and reattach the flushvalve on the tank. Tighten the nut snug, then apply a light film of silicone on the bottom of the gasket to seal it to the bowl.

Reset the tank and tighten the tank to bowl bolts.

Check the fill valve mount nut to insure it is tight also. It could be leaking slightly there and the water adhering to the underside of the tank until it drips making it look like the bolts are leaking.

[jw14]

Thanks, that worked.