The performance of the brakes is also affected by the condition of the tyres, the vehicle load and the alignment of the front wheels.
Checking the operation of the vacuum booster
Release the existing vacuum with the engine off by depressing the brake pedal several times at 5 second intervals. Fully depressing the brake pedal, start the engine. Make sure the clearance between the brake pedal and the floor panel decreases as the vacuum in the engine stabilizes.
Leak test
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 the gap between the brake pedal and the floor panel gradually increases as the brake pedal is depressed. Start the engine. Press and hold the brake pedal, then stop the engine. Hold the pedal down for about 30 or more and check that the pedal travel does not change.
Removing
Do not deform or bend the brake pipes and hoses when removing and installing the brake booster. Replace the earring finger if it is damaged. Do not damage the threads of the brake booster studs. If it is tilted during installation, the threads on the baffle may be damaged.
Disconnect the vacuum tubes from the brake booster.
Remove the master cylinder.
Remove the cotter pin and pin from the earring on the passenger compartment side. Remove the pressure rod from the brake pedal.
Remove the fixing nuts for the brake booster and brake pedal assembly.
Remove the brake booster from the engine compartment.
Checking and adjusting the length of the protruding stem
Using a manual vacuum pump, create a vacuum in the brake booster - 66.7 kPa (500 mmHg Art.).
Pic. 6.29. Push rod length adjustment
Loosen the lock nut and adjust the length of the push rod so that the length «IN» became equal to the given value (pic. 6.29).
Adjust until clearance between stem protrusion and screw is 0 mm - nominal length at 66.7 kPa gauge reading (500 mmHg Art.)
Installation
By adjusting the length «IN», temporarily tighten the lock nut, and install the brake booster to the vehicle.
Connect the brake pedal to the pressure rod earring.
Screw the fixing nuts onto the brake pedal assembly and tighten to the required torque.
Connect the master cylinder to the brake booster.
Adjust the height and free play of the brake pedal.
Tighten the push rod locknut to the required torque.
Remove air.