CRUISE CONTROL AIR BLADDER FAILING AT SAME TIME AS POWER BRAKES/VACUUM-RELATED, INTERCONNECTED SYSTEMS:

https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-cruise-control-vacuum-reservoir

THIS IS WHY EVERYONE NEEDS TO GET A THREE HOUR, PRE-SALES MECHANICAL INSPECTION OF EVERY VEHICLE, NEW/USED BEFORE PURCHASING IT.