[jeffnc]

I'm working on a Mansfield toilet with what I assume is the original flush valve. It's not working right so I replaced it with a Fluidmaster valve. It's a 3 bolt toilet design, and the issue is that I'm not able to get that rear bolt tight enough - there's a slow leak coming from it. I'm scared to tighten it much because the tank is already touching the bowl. I think what happened was the old gasket was a hard rubber design, while the new one is the spongy red style. I think it might be compressing too much.


Should I look for a different gasket? I supposed I could try other things, such as putting some little rubber shim between the tank and bowl and tightening that rear bolt more. Other suggestions?

 

[de-nagorg]

Go to a car parts store, get a tube of Permatex RTV sealant.

Usually RED, or BLUE , in color.

Go home, disassemble this , and form a seal around the hole, with the RTV,

make a liberal bead, and wait a few minutes for it to begin setting up, then gently place the tank on the RTV, to compress it partway.

Let it cure fully, and then bolt it down.

You have made a custom fit seal, that will last until you are gone from the home.

ED

Addition: This stuff smells like vinegar while curing, so use adequate ventilation.

 

[ChuckF.]

You could look in different outlets for a different gasket manufacturer; several companies will make the same dimension gasket but with slight differences, like in the firmness. You could also try a thin film of good quality caulk on both surfaces of the gasket.

 

[jeffnc]

Addition: This stuff smells like vinegar while curing, so use adequate ventilation.

It smells like vinegar because it's silicone. And no, not looking for a pseudo-permanent solution, looking for a more standard solution.

 

[jeffnc]

You could also try a thin film of good quality caulk on both surfaces of the gasket.

How could that help this situation?

 

[de-nagorg]

And no, not looking for a pseudo-permanent solution, looking for a more standard solution.

Good luck.


ED

 

[huesmann]

How could that help this situation?

Uh, it would help seal any gaps left by the gasket?

 

[jeffnc]

Uh, it would help seal any gaps left by the gasket?

What makes you think there are any gaps in the gasket? The problem is that it's leaking from one of the tank bolts.

 

[rjniles]

What makes you think there are any gaps in the gasket? The problem is that it's leaking from one of the tank bolts.

Your initial post was written and interpreted as the bowl to tank gasket is leaking.

Get a replacement 3 bolt tank to bowl kit and replace all bolts and washers per the kit instructions.

Sent from my Moto E (4) Plus using Tapatalk

 

[SPS-1]

Its the tank to bowl gasket, right ?

My experience is that by the time you need to remove the tank (maybe 10 - 30 years), that gasket has taken a set and is not reliable any more. Buy a new gasket. Take along the old gasket, and take a good look at the bowl/tank interface. Maybe take a photo. There are different thicknesses of gasket.

Last one I replaced, the bolts got tight before I had ceramic to ceramic contact. So I tightened it up as much as I dared, and then a few days later snugged it some more until I had ceramic to ceramic contact.

 

[jeffnc]

Your initial post was written and interpreted as the bowl to tank gasket is leaking.

I thought I was pretty clear that there was a leak coming from the rear bolt, but OK.

Get a replacement 3 bolt tank to bowl kit and replace all bolts and washers per the kit instructions.

Yes, that is what I did, and that solved the problem. The issue is (for this and other toilet leaks, I'm sure), is that the older design, where there is just one nut for each bolt (doesn't matter if it's 2 bolts ore 3), is prone to leaking. The one nut is asked to do 2 things: first, it compresses the washer inside the tank, and second it holds the tank tight to the bowl. The much better design IMO is to use 2 nuts per bolt. The first nut goes under the tank and simply compresses the washer inside the tank. Then the tank goes on the bowl, and the second nut tightens the tank to the bowl.

The problem was that the new flush valve kit only came with 2 bolts (2 nuts each). I used the original third bolt and nut in the original way. The new gasket was a little spongier and didn't allow the rear bolt to compress the washer enough. I got a new bolt with 2 nuts and it's now compressed and tight an all seems to work.

 

[jeffnc]

Its the tank to bowl gasket, right ?

No, see above.

 

[huesmann]

What makes you think there are any gaps in the gasket? The problem is that it's leaking from one of the tank bolts.

Bolts don't leak.

 

[rjniles]

They sell 3 bolt kits with a nut for under the tank and another nut to secure the tank to the bowl. Don't buy the ones with wing nuts

 

[jeffnc]

Bolts don't leak.

Well they can actually, but you're right - not this one. And of course, gaskets don't leak either. They might, but that's not what we're talking about when we talk about a gasket leak either right? I mean we can get padantic if we really want to. Even in your original response you talked about leaks around the gasket.

 

[jeffnc]

They sell 3 bolt kits with a nut for under the tank and another nut to secure the tank to the bowl. Don't buy the ones with wing nuts

The issue was I had the flush valve kit, and it came with 2 bolts. My thinking was if the third old style bolt worked before, it should work now. Lesson learned (as I said, I far prefer the 2-nut-per-bolt design anyway.)

But regarding your comment about wing nuts, what's the problem there? The important nut - that seals the tank bolt gaskets - is always going to be a standard nut. Since the nut below only holds the tank in place and doesn't need to be super tight, what is the issue with a wing nut?

 

[bruceb3]

Get a proper Mansfield tank to bowl kit and you'll be fine. Yes, the Mansfield gasket is harder than most.Tighten the bolts evenly a few turns at a time so the tank sits evenly and you don't need any sealant.
Using RTV to make a gasket sounds like a waste of time, money and energy. Can't imagine it working.