Grand Prix V6-191 3.1L (1989)
11. Bleed Powermaster III Isolation Valves:
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Attach bleeder hose to bleeder valve on inboard side of Powermaster III Unit and submerge opposite end in a clear container partially filled
with brake fluid.
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With ignition still on, apply light force to the brake pedal.
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With the brake pedal applied, slowly open bleeder valve and allow brake fluid to flow until no air is seen in the brake fluid.
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Close bleeder valve when brake fluid begins to flow without air bubbles.
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Repeat procedure on outboard side bleeder valve.
12. Bleed accumulator:
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Turn the ignition off and depressurize the Powermaster III Unit. Wait two minutes for air to clear from the brake fluid in the reservoir.
CAUTION: Never check brake fluid level without fully depressurizing the Powermaster III Unit or overfilling will result.
13. Remove reservoir cover and check brake fluid level in both reservoir sections. Using clean DOT 3 brake fluid from a sealed container, fill the
reservoirs to the proper level as necessary.
14. Install reservoir cover and snap all four cover tabs in place on reservoir.
15. Before turning the key to run, manually apply brake pedal with a jabbing (sharp rapid apply) using full force three times.
16. Turn the ignition to "Run" and allow the pump motor to run.
NOTE: Turn the ignition off if pump motor runs for more than 60 seconds, refer to Pump, Brake Fluid / Testing and Inspection.
17. Bleed booster section of Powermaster III Unit:
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Connect tool# 094-00101. Turn ignition to "Run". Without starting the engine, allow the pump to charge the accumulator. When the pump has
stopped, perform the "Solenoid bleed and checkout" test.
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If 094-00101 is not available, depress the brake pedal with moderate pressure and turn ignition to "Run" without starting the engine for 3
seconds. Repeat this "Off/ Run" procedure 10 times to cycle the solenoids.
Inspection:
a. Apply brake pedal and note brake pedal feel and travel. If brake pedal feels firm and smooth without excessive travel, system is properly bled.
Proceed to step 18.
b. If brake pedal feel is soft or spongy or pedal travel is excessive, rebleed front brakes. If excessive brake pedal travel continues, first check the
fluid level, then check for leaks throughout the brake system.
NOTE: Excessive brake pedal travel exists when (while driving the vehicle) braking action does not start until after the first 38 mm (1.5 in.) of
pedal travel.
c. If a "bump" is noted upon initial pedal apply, or pedal apply does not feel smooth and uniform:
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Raise the rear wheels approximately 75-150 mm (3-6 in.) off the ground.
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Depress the brake pedal with moderate pressure. Turn the ignition to the "Run" without starting the engine for 3 seconds. Turn the ignition
back to the "Off" position. Repeat this procedure 5 times.
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Turn the ignition "Off" and depressurize the Powermaster III Unit. Wait 2 minutes for air to clear from the brake fluid in the reservoir.
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Lower the rear wheels.
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Pressurize the system by turning the ignition key to the "On" position without starting the engine.
^
Bleed isolation valves, refer to steps 11 through 13.
18. Road test vehicle and note pedal travel and feel.
Pressure Bleeding
If a Powermaster III unit has been replaced, or air is suspected in the brake lines, the entire braking system must be bled.
If only a hydraulic portion of the Powermaster III unit has been replaced, without allowing air into the brake lines, it may only be necessary to
manually bleed the Powermaster III unit.
Pressure bleeding must be done with diaphragm type bleeding equipment. Use only DOT 3 type brake fluid from a sealed container.
1.
Turn ignition switch to the Off position, then depressurize the Powermaster III unit, refer to DEPRESSURIZING POWERMASTER III.
2.
Clean reservoir cover and diaphragm assembly, then remove assembly.
3.
Check fluid in both reservoir sections, then fill to proper level, using clean DOT 3 brake fluid, if necessary.
4.
Install bleeder adapter tool No. J-37115 or equivalent and secure with attachment cable. Ensure cable does not interfere with bleeder valve access.
5.
Attach bleeder adapter to pressure bleed equipment, charge to 5-10 psi. for approximately 30 seconds, then slowly increase pressure to 30-35 psi.
6.
Bleed adapter tool No. J-37115 or equivalent by connecting a clear plastic hose to adapter bleeder screw and submerging opposite end in a clean
container partially filled with brake fluid.
7.
Slowly open bleeder valve, allowing fluid to flow until no more air is seen in fluid, then close valve.
8.
Raise and support vehicle, then bleed brakes in sequence: right rear, left rear, right front, then left front, as described below.
9.
Attach bleeder hose to bleeder valve, then submerge opposite end in a clean container partially filled with brake fluid.
10.
Slowly open bleeder valve and allow fluid to flow for 20-30 seconds. To aid in releasing entrapped air, lightly tap on caliper castings with a rubber
