I'm replacing all the guts of the toilet. We've owned

>>1234588
If you're replacing the overflow and flapper seat with a new one, just break/cut the old nut off.
If you want to re-use it, why are you taking it off?

>>1234588
assuming you are replacing the flushvalve,
best is hand saw from the inside or across the width
you can also use flat head screw driver between nut and valve body to pry inwards to start breaking it inwards
you can use pliers to break the threads of the flush valve inwards, breaking it into pieces as you go. If you get one slit cut or sawed anywhere along the nut or threads, it'll unscrew or pry off, if it doesn't just fall off on its own.

Not out of the ordinary to saw or break away old nuts on flush valves

>>1234588
take the tank off the bowl

>>1234597
this

File: pliers on flushvalve nut.jpg (17KB, 300x400px) Image search: [Google]

17KB, 300x400px

>>1234597
>>1234601
It didn't even occur to me, but there's no fucking way OP is trying to unscrew the flush valve from inside the tank, right? I mean he does have the tank to bowl bolts and washers off.

I'm assuming it's like pic related and wouldn't turn.

>>1234604
Yep. To replace that bit you have to take the tank off. So it's a new seal and everything. Not difficult to do though. Last one I did it was an old brass fitting. I had to cut it off with an angle grinder.
The only difficult bit is getting the guts back in so they don't bind up. i.e. the flappy bit lines up with the flush lever.

just buy a whole new toilet at that point

>>1234626
No, I meant that I couldn't imagine someone getting to that point without even taking the tank off the bowl.
I made the assumption that since he had already pulled the ballcock and bolts, that he would already have tank off, taken the tank to bowl gasket off, and was only having troubles with getting the nut to turn.
Any time I had replaced old brass flush valve like the rubber disks or flush balls that was in a bind, I just used my saw to cut a slit through one side of the bolt or the body. I can't imagine using an angle grinder in someones bathroom, and I'll be damned if I'm going to take the tank outside when I've already got a saw right there.
But, I may have over estimated OP and he really was trying to unscrew the flush valve from inside the tank, while still on bowl.
>>1234627
So, buying a decent new toilet starting around $200, removing the old one,cleaning up, dealing with any flange issues, mounting it, leveling, caulking, versus a few minutes and less than $20 in parts is the same in your world?
Do you buy a new toilet if a bolt washer starts to drip?

I hope you went ahead and replaced the wax gasket while you were this deep into working on it.