Possible future cruise control issue

[mhallack]

I know it's an odd title, but I am wondering about my cruise control. It clicks on normally, but when I brake to shut it off, the engine will rev high for a second or two before it shuts off. Is this normal or a possible future problem?

 

[Roadrunner777]

That's an odd problem. So, you probably know the cruise control has an actuator near the left hood hinge, with a cable going to the throttle. The cable is pulled by a vacuum diaphragm in the actuator. So, in cc mode, there is vacuum in the actuator holding open the throttle.

The brake pedal opens a dump valve, which is really just a plug on the end of a hose. The plug opens when you press the brake. The hose goes to the actuator. So, pressing the brake opens the hose, letting air in to the actuator, breaking the vacuum, closing the throttle.

The cc module also monitors the brake light circuit and kills the actuator electrically.

I wonder if your dump valve has an issue and it is clogged or stuck closed.