Thanks for the info. I can't find a brand name on the toilet (though I haven't removed it to check thoroughly). It has a logo that looks like a big "T" surrounded by a circle.
However, this toilet only has one pedal, on the left, with the vacuum device suspended on the wall behind it. I suppose I'll have to remove the whole thing and check it out, but my handyman abilities have a remarkable consistency: everything I try to fix usually is made worse. Oh well, onward...
--TB