Alternate Automated Brake Bleed Procedure
ALTERNATE AUTOMATED BRAKE BLEED PROCEDURE (WITHOUT PRESSURE BLEEDER)^ TOOLS AND EQUIPMENT REQUIRED
- Scan Tool
- Delco Supreme II (or equivalent) DOT 3 Brake Fluid
- Plastic Bleeder Bottle (equipped with hose to recover brake fluid)
IMPORTANT: If a pressure bleeder is not available, a manual pedal method can be used with the aid of an assistant. The manual pedal method will consist of the assistant opening and closing bleeder screws or actuating the brake pedal. The manual pedal method will still require the use of a Scan tool to properly bleed the brake system.
The alternate automated brake bleed procedure is used on DBC7 ABS systems. This procedure uses a Scan tool to cycle the solenoid valves and run the pump in order to purge air from the secondary circuits. The automated bleed procedure opens the secondary circuits, then allows trapped air in the Brake Pressure Modulator Valve (BPMV) to flow outwards to the individual corners, where the air is purged from the system.
IMPORTANT: The alternate automated brake bleed procedure is required when one of the following has occurred:
^ Valve assembly removal or replacement.
^ Manual bleed of calipers and wheel cylinders does not obtain desired pedal height or travel.
^ Master cylinder removal or replacement.
^ Extreme loss of brake fluid.
^ Air ingestion is suspected.
PRELIMINARY INSPECTION AND SETUP
1. Inspect battery for full charge. Charge battery or repair charging system if battery not fully charged.
2. Connect Scan tool to DLC connector. Check and repair current or history DTC's prior to performing any brake system bleeding.
3. Inspect for visual damage or leaks, repair as needed.
4. Fill master cylinder reservoir with clean brake fluid. Keep reservoir at least half full during entire bleed procedure.
IMPORTANT: Use only DOT 3 brake fluid. Brake fluid is corrosive. Take care not to allow brake fluid to contact any painted surfaces. Wipe off and clean painted surface immediately if contact is made.
5. Turn ignition switch to RUN, engine Off.
6. Raise vehicle on a suitable support.
7. Connect Scan tool and establish communication with ABS system by following these steps:
7.1 Select DIAGNOSTIC
7.2 Select appropriate model year
7.3 Select SATURN (not passenger car)
7.4 Select CHASSIS
7.5 Select CAR LINE - Z
7.6 Select CONTINUE ("ABS braking is not available when ABS/TCS lamps are illuminated" statement will appear on screen.)
7.7 Select SPECIAL FUNCTIONS
7.8 Select AUTOMATED BLEED ("Connect Required Brake Bleed Equipment" statement will appear on screen. Disregard statement for this alternate automated bleed procedure.)
PERFORMING ALTERNATE AUTOMATED BLEED PROCEDURE
1. With bleeder screws in closed position, Select CONTINUE to start bleed procedure. The first part of the automated bleed procedure will cycle the pump for 60 seconds. After cycling the pump, the Scan tool will go into a cool-down mode for 180 seconds, a 3 minute timer will be displayed. The automated bleed procedure will not continue until the timer has expired, and it cannot be overridden.
IMPORTANT: For the following steps, the assistant should be applying and holding the brake pedal, or opening and closing the designated bleeder screw when appropriate.
2. The Scan tool will instruct to open the right rear bleeder screw first.
2.1 Before starting bleed procedure, assistant should slowly stroke, apply, and hold brake pedal.
2.2 Once brake pedal is in a held position, press START on Scan tool and open bleeder screw simultaneously.
2.3 When brake pedal reaches the floor, close bleeder screw. Assistant can now release brake pedal.
2.4 Assistant should again stroke, apply, and hold brake pedal.
2.5 Open bleeder screw until brake pedal reaches the floor. Then close bleeder screw.
2.6 Repeat this procedure as many times as possible during the Scan tool timed program or until all air is removed.
2.7 Once Scan tool is done cycling the designated brake corner, ensure that the bleeder screw is closed prior to moving on to the next corner.
3. Repeat step 2 with the Scan tool for the remaining brake corners in the following order:
^ Left Rear
^ Right Front
^ Left Front
IMPORTANT: The assistant should continue to apply and hold the brake pedal, or open and close the designated bleeder screw when appropriate.
4. Next, the Scan tool will instruct to open each bleeder screw an additional 20 seconds, starting again with the right rear corner. This will allow any remaining air to purge out of the system.
4.1 Before starting bleed procedure, assistant should slowly stroke, apply, and hold brake pedal.
4.2 Once brake pedal is in a held position, press START on Scan tool and open bleeder screw simultaneously.
4.3 When brake pedal reaches the floor, close bleeder screw. Assistant can now release brake pedal.
4.4 Assistant should again stroke, apply, and hold brake pedal.
4.5 Open bleeder screw until brake pedal reaches the floor. Then close bleeder screw.
4.6 Repeat this procedure as many times as possible during the Scan tool timed program or until all air is removed.
4.7 Once Scan tool is done cycling the designated brake corner, ensure that the bleeder screw is closed prior to moving on to the next corner.
5. Once all four bleeder screws have been opened and closed the Scan tool will display PROCEDURE COMPLETE. The assistant is no longer needed.
6. Torque bleeder screws.
Torque: Bleeder Screws - Front: 11 Nm (97 inch lbs.)
Torque: Bleeder Screws - Rear: 7.5 Nm (66 inch lbs.)
7. Depress brake pedal to gauge pedal height and travel. It may be necessary to repeat steps 1 - 6 if pedal feel and travel are unacceptable.
8. Remove Scan tool from DLC.
9. Lower vehicle.
10. Inspect brake fluid level in master cylinder reservoir, fill as needed with DOT 3 brake fluid.
11. Road test vehicle to verify proper brake pedal height and travel.