I have replaced the flush valve with a whole new kit along with the seal under the tank but when I flush the toilet it gushes water out from under the tank. It only leaks when I flush it. I have tightened all the bolts finger tight as not to over tighten when I replaced the flush valve and seal. So what could the problem be and where is it leaking from. It floods the bathroom every time its not just a little water it's a lot.