How long does the vacuum cruise control switch last?

The cruise control vacuum switch is an integral part of the cruise control system. Once you install cruise control, the negative pressure in the vacuum is used to open and close the mechanical switches. A vacuum switch located on the servo maintains a constant pressure after the cruise control is set. Once it's time to slow down, you can press the slow button on the steering wheel, which releases the vacuum in the servo. After the vacuum is released, the vehicle automatically reacts by reducing speed.

A vacuum system typically contains a one-way check valve and a vacuum storage tank. When the engine has periods of low vacuum, a backup vacuum source can provide the extra vacuum it needs. The speed control in your vehicle is controlled by electronic signals from the cruise control module to modulate the vacuum inside the cruise control servo. The cruise control servo has a vacuum diaphragm connected to the throttle lever by a chain, cable, or linkage.

The cruise control vacuum switch holds the vacuum in place and at the correct pressure until the brake pedal is depressed. Once the brake pedal is depressed, it releases a vacuum, also known as bleeding. Sometimes the vacuum cruise control switch leaks and does not maintain the set speed. If the switch does not open, the cruise control may not slow the vehicle.

There are many parts in a cruise control vacuum system and all of these parts must work properly for the cruise control to work. If the cruise control vacuum switch is not working properly, you may hear a hiss near the pedals. This part can wear and break over time, especially with regular use. Because of this, you should be aware of the symptoms that a cruise control vacuum switch produces before it fails completely.

Signs that the cruise control vacuum switch needs to be replaced include: