OEM 2009 GMC Envoy Brake Booster

2009 GMC Envoy Brake Booster Parts and Q&A

• Q: How to replace the power vacuum brake booster on 2009 GMC Envoy?

  A: To install the new Brake Booster start with applying the parking brake lever and build up vacuum by pressing then releasing the Brake Pedal until it becomes solid. Detach the vacuum sensor power Brake Booster connection first then remove the master cylinder nuts without breaking the pipe connectors. Lift the master cylinder out of the booster while holding it upright with wire support. Detach the vacuum Brake Booster and check valve from the power vacuum Brake Booster by first removing the master cylinder o-ring seal. Take out the power vacuum Brake Booster by first removing its stoplamp switch and nuts. First put the vacuum Brake Booster in place and secure it through the nuts while tightening them to 36 nm (27 lb ft). Install the stoplamp switch afterward by connecting the vacuum Brake Booster and check valve assembly to the power unit while applying denatured alcohol as needed for lubrication except when soap is required. Fit the master cylinder against the power vacuum Brake Booster and guide the o-ring inside its body. Then apply the master cylinder nuts and torque them to 36 nm (27 lb ft). Close the electrical connection to the vacuum sensor on the power Brake Booster if it has one.