Brake Booster Pushrod Clearance Adjustment

Special Tools Required 

Pushrod adjustment gauge 07JAG-SD40100

1. Set the special tool (A) on the master cylinder body (B), push in the center shaft (C) until the top of it contacts the end of the secondary piston (D) by turning the adjusting nut (E).
   Fig 1: Setting Special Tool On Master Cylinder Body

   
2. Without disturbing the center shaft's position, install the special tool (A) backwards on the booster.
   Fig 2: Installing Special Tool Backwards On Booster

   
3. Install the master cylinder nuts (B), and tighten them to the specified torque.
4. Connect the booster in-line with a vacuum gauge (C) 0-101 kPa (0-760 mmHg, 30 in.Hg) to the booster's engine vacuum supply, and maintain an engine speed that will deliver 66 kPa (500 mmHg, 20 in.Hg) vacuum.
5. With a feeler gauge (A), measure the clearance between the gauge body and the adjusting nut (B) as shown in Fig 3 .

   If the clearance between the gauge body and the adjusting nut is 0.4 mm (0.02 in.), the pushrod-to-piston clearance is 0 mm. However, if the clearance between the gauge body and the adjusting nut is 0 mm, the pushrod-to-piston clearance is 0.4 mm (0.02 in.) or more. Therefore it must be adjusted and rechecked.

   Fig 3: Measuring Clearance Between Gauge Body & Adjusting Nut With Feeler Gauge

   
6. If the clearance is incorrect, loosen the star locknut (A), and turn the adjuster (B) in or out to adjust.
   • Adjust the clearance while the specified vacuum is applied to the booster.
   • Hold the clevis (C) while adjusting.
   Fig 4: Loosening Star Locknut & Turning Adjuster To Adjust

   
7. Tighten the star locknut securely.
8. Remove the special tool (D).
9. Check the pushrod length (A) as shown in Fig 5 if the booster is removed. If the length is incorrect, loosen the pushrod locknut (B), and turn the clevis (C) in or out to adjust.
   Fig 5: Checking Pushrod Length

   
10. Install the master cylinder (see Master Cylinder Replacement  ).