Power brake booster — check, removal and installation
Operating check
1. Depress the brake pedal several times with the engine off and make sure there’s no change in the pedal reserve distance.
2. Depress the pedal and start the engine. If the pedal goes down slightly, operation is normal.
Airtightness check
3. Start the engine and turn it off after one or two minutes. Depress the brake pedal slowly several times. If the pedal depresses less each time, the booster is airtight.
4. Depress the brake pedal while the engine is running, then stop the engine with the pedal depressed. If there’s no change in the pedal reserve travel after holding the pedal for 30 seconds, the booster is airtight.
Removal
5. Power brake booster units shouldn’t be dissing- assembled. They require special tools not normally found in most automotive repair stations or shops. They’re fairly complex, and because of their critical relationship to brake performance, should be replaced with a new or rebuilt one.
6. Remove the engine covers (see Tune-up and routine maintenance).
7. Remove the windshield wiper assembly (see Chassis electrical system).
8. Remove the cowl assembly (see Body).
9. Remove the brake master cylinder (see Master cylinder — removal and installation).
10. Remove the air cleaner assembly (see Fuel and exhaust systems).
11. Disconnect the vacuum hose or hoses from the brake booster. Be careful not to damage the hose when removing it from the booster fitting. Note: On 2010 and later V6 models, the metal vacuum One retaining clips and line must be removed.
12. Inside the vehicle, remove the driver’s kick panel, knee bolster and the knee bolster reinforcement brace (see Body).
13. Disconnect the pedal return spring.
14. Locate the clevis which connects the booster pushrod to the top of the brake pedal. Remove the clevis pin-retaining clip with pliers and pull out the pin.
15. Remove the four nuts and washers holding the brake booster to the firewall (you may need a light to see them). Slide the booster straight out from the firewall until the studs clear the holes.
Installation
16. Installation procedures are basically the reverse of removal. Tighten the clevis locknut securely and the booster mounting nuts to the torque listed in this Chapter’s Specifications.
17. After the final installation of the master cylinder and brake hoses and lines, the brake pedal height, free play and pedal reserve distance must be adjusted (see Tune-up and routine maintenance) and the system must be bled (see Brake hydraulic system — bleeding).