My house, built in 1976, has an American Standard Vent Away toilet, series 2003. I know this is an unusual and expensive toilet that is not made anymore. It bubbles up when flushing; I suspect because it has a standard Fluidmaster fill valve instead of the real part, which is totally different. I ordered the part ($200 and an incredible thing to look at) and am having trouble seeing where a long piece of copper tubing goes (it came with the part).
Are there instructions I could get or a diagram of how all these parts work together?
Never heard of this toilet. I would still have a problem believing the fill-valve wold cause bubbling in the toilet though. If the bubbling is occuring in the bowl, it is more likely a venting problem. Check the link below for "some" info on your toilet. May even be your question contained there.