I was on the highway, going up a moderate hill at about 65 mph, and the cruise control "let go" and has not worked since. The feeling was like something released and the speed started to drop, until I pressed the foot pedal. The car is a '90 745 Regina, with 240,000 miles, one-owner, and dealer maintenance since new, although I do a few minor things myself. Any thoughts on what to look at first? Thanks.
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Many thanks for the previous suggestions. Once I had time to check it, it turned out that the Vacuum Servo (the black rubber collapsible "ball" near the back top of the engine) had a hole about the size of the head of a pin. A $75 replacement part from the dealership solved the problem.