Toyota 44610-07111 Booster Assembly, Brake

The brake test for Avalon models has two steps: with the engine off, press and release the brake pedal several times to see if the brake distance stays the same, then start the engine and watch how the pedal moves down slightly. The engine needs to run for one or two minutes, then stop. Brake pedal depression brings good news: you've got an effective air seal in your booster. When you start the engine, you must keep the brake pedal depressed for 30 seconds when shutting down, then let go of the pedal. If the pedal move the same amount, you know the booster is sealed properly. Repairing a power brake booster isn't possible, because it has too many components that affect how the brakes work. Get a new or remanufactured unit to replace it. To lift the brake master cylinder, disconnect the electrical connector for the precharge pump when Vehicle Stability Control is present, detach all hoses and bolts, too. Also remove the air cleaner unit, then unplug the vacuum connection from the brake booster. Before starting work, drivers must remove the kick panel underneath, knee bolster, reinforcement brace, and other parts directly near the brake pedal. First, the attaching pin between the brake pedal and booster pushrod gets taken off. Then, two nuts and washers need to come out to detach the brake booster from the firewall. You reinstall the booster by tightening the clevis locknut and mounting nuts to the correct tightening force. When you put a new power brake booster unit in, you need to check and adjust the pushrod clearance first, then set the brake pedal height, make it easy to push down, and clear all air from the system.

Power brake booster units should not be disassembled and require special tools, making replacement with a new or rebuilt unit necessary. Start by removing the brake master cylinder, charcoal canister, and air cleaner assembly, then disconnect the vacuum hose from the brake booster. Inside the vehicle, remove the steering column cover pad and locate the clevis connecting the booster pushrod to the brake pedal. Remove the clevis pin retaining clip and the pin. Finally, remove the four nuts and washers securing the brake booster to the firewall and slide it out.