Yukon Denali 2WD V8-6.0L Hybrid (2010)
Vacuum Brake Booster: Service and Repair
Power Vacuum Brake Booster Replacement
Removal Procedure
1. Place the ignition switch in the OFF position.
2. Apply and release the brake pedal several times until the brake pedal becomes firm to deplete the power vacuum brake booster vacuum reserve.
3. Disconnect the electrical connector and remove the power brake booster vacuum sensor (1) and vacuum hose and position aside.
4. Remove the brake master cylinder nuts (1).
5. Without disconnecting the brake pipe fittings from the master cylinder, remove the brake master cylinder and support with heavy mechanics wire
or equivalent.
6. Inspect the O-ring seal on the master cylinder body for damage and replace, if necessary.