Toilet Repair
I had a the same problem, assuming that you have pressure in the line, the water control valve is bad. It's located on the back, near the top.
Check the supply line to the toilet for blockages and flush the line just to be sure. I removed the toilet and ran a temperary tube into a bucket. Always replace the floor flange gasket to avoid furture leaks.
In my 97 towlite, I had a AQUA MAGIC IV, I was able to get a replacment water control valve kit. I installed it and could not get the O-ring to seat, causing it to leak, even changing to different O-rings with no luck.
The valve from the factory didn't quite match up to my old toilet and caused a small drip.
I ended up replacing the toilet to a AQUA MACIC V. I oppted for the hand operated one because the foot operated pedal took up floor space when I steped out of the shower.
Les 97 21ft. towlite 06 Toyota Tocoma