- Disconnect servo cable from throttle lever. Disconnect servo electrical connector. Using a fused jumper wire, apply battery voltage to Dark Blue/White wire terminal of servo connector. Jumper Black wire terminal of servo connector to ground.
- If vent solenoid is not heard clicking, replace servo. If vent solenoid is heard clicking, disconnect hose from large fitting on servo. Connect vacuum pump to large fitting on servo. Apply 10-20 in. Hg to diaphragm. If diaphragm moves in completely and vacuum does not decrease quickly, go to BRAKE RELEASE VALVE TEST. If diaphragm does not respond as specified, replace servo.
Home/GMC/Typhoon/GMC Typhoon I (1991-1993)/Repair manual/Cruise Control Systems/Servo Vent Valve Check
Contents
Section: Cruise Control Systems- Description & Operation
- Description
- Cruise Control Module
- Cruise Control Switch
- Set/coast
- Resume/accel
- Servo Assembly
- Astro, Bravada, Safari, Sonoma, Syclone, Typhoon & "s" & "t" Series Blazer, Jimmy & Pickup
- Suburban, Van & "r" & "v" Series Blazer, Jimmy & Pickup
- Lumina Apv, Silhouette & Trans Sport
- Brake & Clutch Release Switch/valve
- Brake & Clutch Release Switch/valve Adjustment
- Astro, Safari, Sonoma, Syclone, Typhoon & "s" & "t" Series Blazer, Jimmy & Pickup
- Bravada
- Cruise Control Does Not Engage
- Drac (speed Sensor Buffer) Inoperative
- Cruise Control Does Not Disengage Using Brake Pedal
- Speed Sensor & Buffer
- Source Vacuum Check
- Servo Vacuum Valve Check
- Servo Vent Valve Check
- Brake Release Valve Test
- Wiring Diagrams
- Abbreviations
- Accessory Drive Belts
- Adjustments
- Anti-Lock/traction Control
- Application
- Automatic Trans
- Auxiliary Emission Control Systems
- Basic Trouble Shooting
- Brakes
- Charging System
- Check Lists
- Clutches Manual & Hydraulic
- Computer Relearn
- Cooling System (mechanical)
- Cruise Control Systems
- Diagnostic Connector Locations
- Differentials & Drive Axles
- Door Locks & Anti-Theft Systems
- Driveline/axles
- Driveshaft & Universal Joints
- Electrical
- Electrical Component Locations
- Electronic Suspension
- Emission Applications
- Engine
- Engine Performance
- Fuses & Circuit Breakers
- Gauges & Instrument Panels
- General Servicing - All Makes
- Heated Glass/defoggers
- Heater
- Identification
- Manual & Power Steering
- Manual HVAC System
- Manual Trans
- MAP Guidelines
- Mechanical
- Mechanical - Hydraulic
- Metric Conversions
- Mirrors
- Pin Voltage Charts
- Procedures
- Removal & Installation
- Reset Procedures
- Rpo Codes
- Sensor Range Charts
- Specifications
- Starter
- Steering
- Steering Column
- Steering Column Switches
- Steering Gear
- Suspension Front
- Suspension Rear
- Testing & Diagnostics
- Theory & Operation
- Traction Control Disable
- Transfer Case
- Transmission
- Wheel Alignment
- Windows
- Wiper/washer Systems
- Wiring Diagrams - Engine Performance