The rubber boots on the rudder pedals of the 1979 Piper Archer II I share ownership of were falling off. They were originally glued to the metal pedals.
My first attempt at repair involved contact cement from the hardware store. I scraped the rubber and the metal surfaces as best I could, applied the contact cement, and pressed them together. After a few minutes it was clear they weren’t sticking.
I made some upgrades for attempt #2. I ordered some 3M 1300 neoprene contact cement. I bought Methyl Ethyl Ketone solvent from Home Depot for cleaning the surfaces, and I brought heat.
I washed the rubber boot in hot water because I knew it had been exposed to brake fluid last year. I warmed the metal pedal and the rubber boot with a hair dryer. (It was 56 degrees F in the hanger. 3M recommends 65+ degrees for the 1300 cement. I probably warmed them to 85 degrees.) I wiped down the boot and the pedal with the MEK solvent. I applied the 1300 cement, let it dry for a couple of minutes, and pressed the pieces together.
The bond was instant and as of a couple of weeks later it’s still holding fast. I gave the same treatment to two other loose rudder pedal boots, and they are now solid as well. Hope this info helps someone with the same problem.