Power Brake Assist: Service and Repair
REMOVAL- LHDNOTE: Before proceeding, Refer to Service Precautions.
1. Disconnect negative (ground) cable from the battery and isolate the cable.
2. Disconnect the positive cable from the battery, then remove the battery from the battery tray. There is one nut securing the clamp on the backside of the battery holding it in place.
3. Remove the one nut and one bolt securing the air cleaner box in place, then disconnect the wiring harness connector at the air inlet sensor.
4. Lift the air cleaner box upward enough to clear its grommeted alignment post, then move the air cleaner box forward just enough to access the battery tray mounting bolts.
5. Remove the 2 bolts, then the 2 nuts mounting the battery tray to its bracket. Remove the battery tray.
CAUTION: The vacuum in the power brake booster must be pumped down before removing the master cylinder to prevent the booster from sucking in any contamination. This can be done by pumping the brake pedal 4-5 times while the engine is not running until a firm brake pedal is achieved.
6. Remove the master cylinder.
7. If the vehicle is equipped with ABS, remove the Integrated Control Unit (ICU).
8. If the vehicle is equipped with ABS, remove the three bolts securing the ICU mounting bracket to the frame rail.
9. Disconnect the vacuum hoses from the check valve on the power brake booster, but do not remove the check valve from Dower brake booster.
10. Locate the brake pedal-to-power brake booster input rod attachment under the instrument panel. Position a small screwdriver under the center tang of the retaining clip. Rotate the screwdriver enough to allow the retaining clip tang to pass over the end of the brake pedal pin. Remove the clip.
CAUTION: Discard the used retaining clip, it is not to be reused. Replace the clip with a new one on reassembly.
11. Remove the four nuts attaching the power brake booster to the instrument panel. The nuts are accessible from under the instrument panel in the area of the brake pedal bracket.
12. Slide the power brake booster forward until mounting studs clear the instrument panel. Turn the booster sideways, then remove it from the vehicle.
REMOVAL- RHD
1. Disconnect and isolate the negative battery cable.
CAUTION: Pump the brake pedal several times to relieve the vacuum in the power brake booster. This will prevent the booster from sucking in any contamination when the master cylinder is removed.
2. Remove the master cylinder from the vehicle.
3. Remove the air cleaner assembly.
4. Remove the battery and battery tray from the vehicle.
5. Remove the heater core coolant supply tube support bracket bolts.
6. Remove the (2) coolant reservoir retaining bolts from the dash panel. Disconnect the coolant overflow hose from the thermostat housing and remove the coolant reservoir from the dash panel.
7. Working from underneath the instrument panel, disconnect the brake pedal push rod. Remove the retaining clip from the end of the brake pedal mounted stud, then slide the push rod straight off the pin.
8. If equipped, disconnect the clutch pedal push rod. Depress the plastic retention clip on the end of the clutch pedal mounted stud, while sliding the push rod straight off the stud.
9. Rotate the clutch master cylinder to line up the square shaped retaining boss with the square shaped opening in the brake pedal support bracket.
10. Remove the (4) brake booster retaining nuts.
11. Working from inside the engine compartment, remove the (2) clutch fluid reservoir retaining bolts from the dash panel.
12. Remove the clutch master cylinder from the dash panel by pulling it straight out. Position the reservoir and line assembly out of the way.
13. Remove the brake booster from the dash panel by pulling it straight out, then rotate the booster and slide it between the engine and the dash panel towards the battery tray. Slide the booster under the heater core coolant supply hoses and out of the engine bay.
INSTALLATION- LHD
1. Turn the power brake booster sideways, then install it into the engine compartment down past the heater hoses and the strut tower. Rotate the booster so its four mounting studs and input rod are pointed straight toward the instrument panel. Slide the input rod and studs through the instrument panel and into mounting position.
2. Under the instrument panel, install the four power brake booster mounting nuts. Tighten the nuts to a torque of 34 Nm (25 ft. lbs.).
3. Using lubriplate, or an equivalent, coat the surface of the brake pedal pin where it contacts the brake booster input rod.
CAUTION:
- Use only a new brake booster input rod to-brake pedal retaining clip to ensure proper retainment.
- Install a new brake lamp switch anytime the old switch is removed, the brake booster or pedals have been changed or removed.
4. Connect the power brake booster input rod-to brake pedal pin. Install a new retaining clip. Do not use the old clip.
5. Install and adjust a new brake lamp switch.
6. Connect all previously removed vacuum hoses to the vacuum check valve.
7. If the vehicle is equipped with ABS, install the ICU mounting bracket on the frame rail using its three bolts. Tighten the nuts to a torque of 23 Nm (200 in. lbs.).
8. If the vehicle is equipped with ABS, reinstall the ICU.
9. Install the master cylinder.
10. Position the battery tray back in place. Install the two bolts, then the two nuts mounting the battery tray to its bracket. Tighten the two bolts and nuts to a torque of 34 Nm (25 ft. lbs.)
11. Reinstall the air cleaner box onto its grommeted alignment post.
12. Install the one nut and one bolt securing the air cleaner box in place, then connect the wiring harness connector at the air inlet sensor.
13. Install the battery and clamp it in place.
14. Connect the positive, then the negative (ground) cable on the battery.
15. Bleed the base brake system.
16. Road test the vehicle to ensure proper operation of the brakes.
INSTALLATION - RHD
1. Position the brake booster on the dash panel by reversing the path taken to remove the booster. Slide the booster under the plenum on the battery tray side of the engine compartment. Slide the booster between the engine and dash panel until it can be installed on the right side of the dash panel.
2. Reinstall the vacuum supply hose on the booster check valve. Make sure the booster check valve is firmly seated in the rubber grommet and did not become dislodged during the booster installation.
3. If equipped, install the clutch master cylinder through the dash panel.
4. Install the clutch fluid reservoir. Torque the retaining bolts to 7 Nm (62 in. lbs.).
5. Working from underneath the instrument panel, install the four brake booster retaining nuts. Torque the nuts to 34 Nm (25 ft. lbs.).
6. Grease the brake pedal pin and slide the brake booster push rod onto the pedal pin. Install the retaining clip.
7. If equipped, lock the clutch master cylinder in position. Rotate the clutch master cylinder to line up the square shaped retaining boss with the square shaped opening in the brake pedal support bracket. Once the cylinder is inserted through the brake pedal support bracket rotate 90� to lock it in position.
8. Connect the clutch pedal push rod. Slide the push rod on the clutch pedal mounted stud until the plastic retention clip locks it in place.
9. Install the coolant reservoir. Torque the retaining bolts to 7 Nm (62 in. lbs.). Connect the coolant overflow hose on the thermostat housing.
10. Install the heater core coolant supply tube support bracket bolts. Torque the bolts to 36 Nm (27 ft. lbs.).
11. Install the battery and battery tray in the vehicle.
12. Install the air cleaner assembly.
13. Install the master cylinder on the vehicle.
14. Fill the brake fluid reservoir to specification.
15. Bleed the air from the brake hydraulic system.
WARNING: Be certain a firm brake pedal is achieved before attempting to move the vehicle.