Contents: Checking the operation of the vacuum…↓ Checking for leaks ↓ Removal ↓ Checking and adjusting the length of…↓ Installation ↓
The brake booster, located on the firewall, operates using the vacuum in the intake manifold and atmospheric pressure. After completing each operation that involved removing any of the brake system components, perform a test drive to check the operation of the vehicle's brakes. Test the brakes while driving on a clean, dry, and level road. Other test conditions may result in inaccurate results. Test the brakes at various speeds, with both low and high brake loads. The vehicle should stop smoothly, without pulling to one side. Avoid locking the brakes, as this will damage the tires and reduce braking efficiency and control.
The operation of the brakes is also affected by the condition of the tires, the vehicle load and the alignment angles of the front wheels.
Checking the operation of the vacuum booster
Release any vacuum with the engine off by depressing the brake pedal several times at 5-second intervals. With the brake pedal fully depressed, start the engine. Make sure that the gap between the brake pedal and the floor panel decreases as the engine vacuum stabilizes.
Checking for leaks
Start the engine and let it idle for about 1 minute. Shut it off by applying vacuum to the booster. Press the brake pedal several times with normal force and release the existing vacuum. Make sure that when you press the brake pedal, the gap between the brake pedal and the floor panel gradually increases. Start the engine. Press the brake pedal and hold it down, then shut off the engine. Hold the pedal down for about 30 seconds or more and make sure that the pedal travel does not change.
Removal
Do not deform or bend the brake pipes and hoses when removing and installing the brake booster. Replace the clevis pin if it is damaged. Do not damage the threads of the brake booster studs. If it is tilted during installation, the threads can be damaged by the partition.
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Disconnect the vacuum lines from the brake booster.
Remove the master cylinder.
Remove the cotter pin and pin from the shackle on the passenger side. Remove the pressure rod from the brake pedal.
Remove the brake booster and brake pedal assembly mounting nuts.
Remove the brake booster from the engine compartment.
Checking and adjusting the length of the protruding rod
Using a hand vacuum pump, create a vacuum in the brake booster of 66.7 kPa (500 mm Hg.).
Fig. 6.29. Adjusting the length of the push rod
Loosen the lock nut and adjust the length of the push rod so that length "B" becomes equal to the specified value (Fig. 6.29).
Adjust until the gap between the protruding part of the stem and the screw is 0 mm - nominal length with a vacuum gauge reading of 66.7 kPa (500 mm Hg.)
Installation
After adjusting the length "B", temporarily tighten the lock nut and install the brake booster on the vehicle.
Connect the brake pedal to the push rod earring.
Install the mounting nuts onto the brake pedal assembly and tighten to the specified torque.
Connect the master cylinder to the brake booster.
Adjust the height and free travel of the brake pedal.
Tighten the push rod lock nut to the required torque.
Remove air.