What is the Cruise Control Vacuum Bleed Switch all about?
When you set the cruise control on your vehicle, engine vacuum comes into play. The negative pressure contained in the vacuum lines can be used to open and close mechanical switches. Such is the case with the cruise control system. A vacuum switch at the servo holds a steady pressure once the cruise control is set. When it’s time to slow down, there is an electronic button on your steering wheel or column that releases the vacuum in the servo. If that button doesn’t operate properly, a second switch will deactivate the cruise. This is the vacuum bleed switch, which is mounted behind the brake pedal.
The bleed switch remains closed and holds vacuum steady until the brake pedal is pressed. Once the brake pedal presses the bleed switch, it ‘bleeds’ or releases the vacuum and your vehicle will slow down. If the cruise control vacuum bleed switch is leaking vacuum, your cruise control will not hold a set speed. If the switch will not open when pressed, it may be difficult to cancel the cruise control operation to slow your vehicle down. A leak in the vacuum bleed switch will usually produce a hissing noise under the dash by the pedals.
Keep in mind:
- The cruise control has a redundant switch to make sure the system turns off properly.
How it's done:
The Cruise Control Vacuum bleed switch is verified that it needs to be replaced. The switch is located near or on the servo assembly on the inner fender.
The defective Cruise Control Vacuum bleed switch is removed by disconnecting vacuum and electrical connections.
The new Cruise Control Vacuum bleed switch is installed and connected.
The Cruise Control Vacuum bleed switch is tested for operation.
The vehicle is road tested for proper operation of the Cruise Control system.
You won’t need to replace the cruise control vacuum bleed switch during the life of your vehicle unless it fails unexpectedly or is broken. As it is part of the vacuum system in your vehicle, there is no maintenance required. If your cruise control will not hold a set speed or is hard to disengage, have one of our expert technicians inspect and repair your cruise control system.
What common symptoms indicate you may need to replace the Cruise Control Vacuum Bleed Switch?
- Cruise control will not set and hold speed
- Cruise control is difficult to disengage when the brake pedal is pressed
- Hissing noise from under the dash except when the brake pedal is pressed
How important is this service?
Cruise control is convenient for vehicle operation but not a requirement or safety item. If the cruise control bleed switch doesn't function, there is a redundant switch that should cancel the cruise control set speed as well. Have the bleed switch repaired at your leisure.