I recently moved into a 40 year old home.
One of the toilets works just fine but the
water level in the bowl was pretty low. I
noticed the flush valve was blowing water
out the side and maybe there was not enough
water going down the tube to the bowl. I
replaced the valve and now plenty of water
is flowing into the bowl but it seems to all
run off and drop back to the same old level
as before.

Any ideas???