Hello. I read previous questions regarding fluidmaster valve seal replacement #242. I bought this part because my toilet sometimes doesn't fill back up. However, the valve seal (new one) is different than my old one. The new seal has a nipple extension in the middle. My old seal is hollow in the middle? Do I need to do something with the new one? Did I buy the wrong part? There is no way to fit he new part in the mechanism. Thanks.

Hello. I read previous questions regarding fluidmaster valve seal replacement #242. I bought this part because my toilet sometimes doesn't fill back up. However, the valve seal (new one) is different than my old one. The new seal has a nipple extension in the middle. My old seal is hollow in the middle? Do I need to do something with the new one? Did I buy the wrong part? There is no way to fit he new part in the mechanism. Thanks.
. FluidMaster #102, 200, 200A. And 400A ballcocks take a #242 seal.
To replace it you will have to shut the water off to the tank and take the tank lid off. Twist the top of the ballcock off counterclockwise, (see image) and pull up. Pry out the seal and replace it. Reassemble, turn the water back on and give it a flush. Better now? Regards, Tom