I have Gerber toilets that were installed in the mid 80’s. I recently had problems with the tank internals not working properly on two of these toilets, so I bought a universal replacement kit. When I install the universal kit, the tank holds water fine, but the problem appears when I try flushing the toilet. Water starts leaking from the two bolts that hold the tank to the base. It almost seems that the water refilling the bowl from the tank is leaking from the rubber gasket between the two. Any advice? Is a universal kit compatible with this type of toilet or do I need a very specific part? THanks.