Vacuum Brake Booster: Adjustments

DESCRIPTION
The power brake booster (2005) has adjustable push rod (output rod) which is used to compensate for dimensional variations in assembled power brake booster. The push rod length is adjusted after each power brake booster power unit has been assembled in production. A properly adjusted push rod that remains within power brake booster after it was assembled in production should never require service adjustment.

SERVICE INDICATORS
A power brake booster suspected of having improper push rod length will indicate either of the following:
- A push rod which is too long will prevent brake master cylinder piston from completely releasing hydraulic pressure and cause brakes to drag, and result in pre-mature pad/shoe failure.
- A push rod which is too short will increase brake pedal travel and cause a clunk or groaning noise from power brake booster.





REMOVAL
1. Apply service brake pedal several times to exhaust all vacuum in the system.
2. Disconnect brake fluid level warning switch connector if necessary.
3. Remove nut retaining cowl top inner panel tube to brake master cylinder.
4. Disconnect cowl top inner panel tube from cowl and remove.
5. Remove two nuts retaining brake master cylinder to power brake booster assembly.
6. Slide brake master cylinder forward and upward.
7. Brake master cylinder must be supported to prevent damaging brake tubes.

ADJUSTMENT PROCEDURE

CAUTION: Do not adjust push rod length too long or brake drag could result.








- A force of approximately 22 Nm (5 lb) applied to push rod with gauge will make sure push rod is seated within the power brake booster.
- With engine running, check and adjust push rod length so it is between 5.84 mm (0.23 inch) and 6.22 mm (0.245 inch) as checked by gauge shown.
- If adjustment is necessary, grip rod only by knurled area.

INSTALLATION
1. Install brake master cylinder on power brake booster.
2. Gradually alternate tightening of retaining nuts to 21-29 Nm (16-21 ft.lbs).
3. Connect cowl top inner panel tube to cowl.
4. Install nut retaining cowl top inner panel tube to brake master cylinder and tighten to 21-29 Nm (16-21 ft.lbs).
5. Install primary and secondary brake tubes to brake master cylinder outlet ports. Tighten to 16-20 Nm (12-14 ft.lbs).
6. Connect brake fluid level warning switch connector.
7. Fill brake master cylinder reservoir with specified brake fluid to MAX line with High Performance DOT-3 Motor Vehicle Brake Fluid.
8. Bleed brake system.