Brake Master Cylinder: Adjustments

NOTE: Master cylinder pushrod-to-piston clearance must be checked, and adjusted if necessary, before installing master cylinder.

Installation Of The Pushrod Adjustment Gauge:

1. Set the special tool on the master cylinder body; push in the center shaft until the top of it contacts with the end of the secondary piston by turning the adjusting nut.
2. Without disturbing the center shaft's position, install the special tool upside down on the booster.
3. Install the master cylinder nuts and tighten to the specified torque.
4. Connect the booster in-line with a vacuum gauge 0-30 in Hg (0-760 mmHg) to the booster's engine vacuum supply, and maintain a engine speed that will deliver 20 in Hg (500 mmHg) vacuum.

Checking Pushrod Clearance With Feeler Gauge:

5. With a feeler gauge, measure the clearance between the gauge body and the adjusting nut as shown.
Clearance:
Cars without ABS: 0-0.02 in (0-0.4 mm)
Cars with ABS: 0-0.01 in (0-0.2 mm)

NOTE: If the clearance between the gauge body and adjusting nut is 0.02 in (0.4 mm) [cars with ABS: 0.01 in (0.2 mm)], the pushrod-to-piston clearance is 0 mm. However, if the clearance between the gauge body and adjusting nut is 0 mm, the pushrod-to-piston clearance is 0.02 in (0.4 mm) [cars with ABS: 0.01 in (0.2 mm)] or MORE. Therefore, it must be adjusted and rechecked.

6. If the clearance is incorrect:

Booster Pushrod Adjustment:

- Cars without ABS: loosen the star locknut and adjust the clearance by turning the adjuster in or out while holding the pushrod. Tighten the star locknut to the specified torque and remove the special tool.

NOTE:
^ Adjust the clearance while the specified vacuum is applied to the booster.
^ Hold the clevis while adjusting.

Pushrod Clearance Adjustment:

- Cars with ABS: remove the special tool and adjust the clearance by turning the adjuster in or out while holding the output rod.

Fig. 3 Pushrod Length:

7. Adjust the pushrod length as shown if the booster is removed.
8. Install the master cylinder, refer to Master Cylinder and Booster Replacement.
9. After installation, perform the following inspections and adjust if necessary.
^ Brake pedal height, refer to Pedal Height.
^ Brake pedal free play, refer to Pedal Height.