Do you have to put toilet cauking under base of toilet

Bowl ... the toilet bowl?
If that is correct, check the seal between the pan and the pipe.

if you cannot get it to unseat you can take a hacksaw and carefully cut the bolts from under seat on top of toilet base easiest way to remove seat

turn off water to toilet,get a new wax ring,unbolt toilet,lift toilet off floor,scrape wax off floor and under toilet put down ring wax side up,set toilet,kneel on toilet not wobbling,put bolts back on,turn on water,if it sounds to hard,it is,call a plumber follow rays answer

If you;re sure its under the toilet, look for a crack in the base, especially around the retianing bolts, or the wax bowl seal is gone, needs replacing.

Install wax ring around base waste pipe. Make sure that 2 bolts are sticking out of a track under the toilet.Put toilet bolts through toilet holes and tighten nut with washer on each bolt to lock down the toilet. Now attache the water line that goes into toilet and bidet.

Shut off water to tank and drain tank by flushing , then use a sponge to soak up any left. Disconnect water line, then 2 of 1/2" nuts at base of toilet ( floor ) . Lift toilet off, clean old wax off toilet and flange at floor, and install new wax gasket. Set toilet down straight and aligned with gasket and flange as well as studs. Make sure toilet is all way down on new wax gasket ( sit on it and move around a bit until toilet feels steady on floor ) then put nuts washers etc back on and snug it up. Don't tighten too much and snap base, just good and snug.

This is not an easy one as it could be a lot of different thing causing this problem. The easiest one first, check to see if the bolts holding the toilet to the closet collar are tight they may be under the two half round covers on either side of the toilet bowl. If they are not tight you can try tightening them be real careful not to break the bowl flanges. If that doesn't fix the problem you will need to take up the toilet and see if the toilet flange is in good shape and that the floor has not rotted out or that the bolts have not pulled loose from the closet flange.

As you can see this could get into a lot of work.

Good Luck.

you scrape it - first with a flat screwdriver, the remains with a small cutter.

yes it is a wax seal under the toilet, There is just 2 screws holding it down to the floor. Anybody could take it up and fix it.

The bolts are on the two sides down on the base. Prob has small square covers over them

It's not terribly complicated, assuming that by "install a new toilet" you mean where there was alredy an existing toilet. First, remove the old toilet. Shut off the water supply valve, and flush the toilet. Then use a spone to get rid of the water that remains in the tank. Remove the nuts on the two bolts at the base of the toilet where the toilet meets the floor. These are usually hidden under two plastic caps. Now gently rock the toilet until it comes away from the floor. Get help to carry it out. Clean up the old wax that's around the flange where the pipe disappears into the floor. Don't be a wuss, it's only wax. Now you'll need the new toilet, a new supply line, new mounting bolts (don't reuse the old ones) and a two wax rings. Yes, I said two wax rings. You'll see why in a minute. Assemble the new toilet according to the instructions provided. Now here's a warning: Do NOT overtighten the bolts the hod the tank to the bowl. You're dealing with ceramics here, don't break them. Now, put the new hold-down bolts in place on the flange. Read the insturctions that came with the toilet, but you have to do this NOW. Now you'll need a helper. With the toilet upsided down, unwrap a wax ring. Make sure it's room temprature or it won't seal. Press the wax ring around the outlet flange on the base of the toilet. Now you and your helper carefully turn the toilet over without crushing the wax ring. Lift the toilet and slowly lowe it so the wax ring is centered over the "flange" which is where the sewer pipe goes into the foor. Then press the toilet firmly in place. Now if you're like most people, you screwed up here and crushed the wax ring without being centered on the flange. That's why I told you to buy two. Now you know what not to do, scrape off the first one and start again. When you've got the toilet sealed on the flange, connect and tighten the nuts on the bolts. Now you may have to use a hacksaw to cut off the remaining ends of the bolts so you can get the neat little plastic caps to fit. Now connect the water supply line. Now's where you start praying. Turn on the water and let the tank fill. Check the supply line for leaks. Fix as necessary. Now flush. Is water running out from around the base of the toilet? No? Good, you got a good seal. Yes? Very bad. Time to go back to the home center for yet another wax ring. Repeat the sealing process and get a good seal this time.