Hold a hacksaw blade up to the nut where it meets the underside of the bowl.
Toilet unscrew lock nut.
Heat the tip of an old screwdriver and it ll split the nut when it melts through to the shank.
Once it begins turning release.
Start by rocking the bolt by tightening then loosing this may be all you need to break through the rust.
Hold the bolts in place with the screwdriver as you turn the plastic nuts on the underside of the back of the toilet s bowl.
Place the plastic nuts in a safe location and pull up on the back of the toilet s seat.
When you unscrew the screw the pliers will hit against the toilet bowl and prevent the nut from turning and it will loosen.
Some nuts have wings that you can grasp with your fingers.
Don t twist the screwdriver until the plastic cools it ll then snap right off.
Turn the handle on the supply valve all the way to the right to cut the water supply.
Empty the bucket and place it underneath the water supply line.
Hold the bolt steady while you turn the nut counterclockwise.
Works great for kitchen sink holding nuts lav faucets.
Another great tool i have found that is made by irwin tools is there original locking wrench.
Step 3 spray penetrating lubricant in the threads of the plastic bolt if the nut does not unthread easily.
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Then finish loosening the nut with your fingers.
If the nuts don t have wings lock a pair of locking pliers around each one in turn.
To locate the supply valve follow the water supply line or hose from the underside of the tank to where it meets the supply valve at the wall.
Cut off the stuck bolts if you cannot remove the screws.
Eventually and in an effort to save money some of the companies started shipping these ballcocks with a white metal nickel composite lock nut and coupling nut.
Locate the coupling nut on the underside of the toilet tank.
Shut the water supply off for the toilet where you will be removing the lock nuts.
Try a 6 point wrench or socket on your seized nut bolt.
Loosen the nuts with an adjustable wrench.
Grip the top of one of the bolts with adjustable pliers then fit an adjustable wrench around the nut.
While turning these stabilize the bolt from above with a screwdriver.
Use a pair of pliers to just loosen the coupling nut.
I have done this before and always seem to have a problem.
I am trying to replace the valves inside the toilet tank.
Try and avoid 12 point wrenches and sockets as they likely to slip and strip the bolt head.
If you can t grip the nuts with the wrench use a pair of pliers.