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Footbrake System: Maintenance Saab 9-4X I

Mechanical - Hydraulic 47 illustrations ~2401 words

Hydraulic Brake Master Cylinder Fluid Reservoir

Contains supply of brake fluid for the hydraulic brake system.

Brake Fluid Loss

StepActionYesNo
DEFINITION: Brake fluid level is low not related to lining wear.
1Were you sent here from the Hydraulic Brake Symptom table?Go to Step 2Go to DIAGNOSTIC STARTING POINT - VEHICLE
2Inspect the following hydraulic brake system components for brake fluid leaks: Flexible brake hose connections; threaded and bolted Flexible brake hose crimp joints Brake pipe fittings Caliper piston seals Wheel cylinder piston seals, if equipped Master cylinder reservoir Master cylinder reservoir low pressure hose, if equipped Brake pressure modulator valve (BPMV) assembly, if equipped Repair or replace components as necessary. Refer to HYDRAULIC BRAKE SYSTEM DIAGNOSIS . Did you find and correct a condition?Go to Step 8Go to Step 3
3Is the vehicle equipped with a vacuum brake booster?Go to Step 4Go to Step 6
4Disconnect the vacuum check valve from the booster to relieve vacuum reserve. Separate the master cylinder from the vacuum brake booster. Do not disconnect any brake pipes. Inspect the rear of the master cylinder for a brake fluid leak. Inspect for brake fluid in the vacuum brake booster. Did you find a brake fluid leak?Go to Step 5Go to DIAGNOSTIC STARTING POINT - VEHICLE
5Replace the brake master cylinder and the vacuum brake booster. Did you complete the replacement?Go to Step 8
6Wipe clean the external surface of the master cylinder to hydraulic brake booster area, if equipped. Separate the master cylinder from the hydraulic brake booster, if equipped. Do not disconnect any brake pipes. Inspect the rear of the master cylinder for a brake fluid leak. Did you find a brake fluid leak?Go to Step 7Go to DIAGNOSTIC STARTING POINT - VEHICLE
7Replace the brake master cylinder. Did you complete the replacement?Go to Step 8
8Install or connect components that were removed or disconnected during diagnosis. Road test the vehicle to confirm proper operation. Refer to BRAKE SYSTEM VEHICLE ROAD TEST . Is the condition still present?Go to Step 2System OK

Hydraulic Brake System Flushing

Refer to BRAKE FLUID IRRITANT WARNING .

Refer to CAUTION: EFFECTS OF BRAKE FLUID ON PAINT AND ELECTRICAL COMPONENTS .

  1. Inspect the brake fluid for the following conditions, indicating brake fluid contamination: Fluid separation, indicating 2 types of fluid are present; a substance other than the recommended brake fluid has been introduced into the brake hydraulic system Swirled appearance-oil-based substance Layered appearance-silicone-based substance Fluid discoloration, indicating the presence of moisture or particles that have been introduced into the brake hydraulic system Cloudy appearance-moisture Dark appearance/suspended particles in fluid-dirt, rust, corrosion, brake dust
  2. Inspect the master cylinder reservoir cap diaphragm and the reservoir-to-master cylinder grommets for swelling, indicating brake fluid contamination.
  3. If the brake fluid WAS contaminated with an oil-based or a silicone-based substance, indicated by fluid separation and/or a swollen master cylinder reservoir cap diaphragm and/or swollen reservoir-to-master cylinder grommets, perform the following: Remove ALL of the following components listed from the vehicle. Each component contains internal rubber seals/linings which have been contaminated by the contaminated brake fluid in the brake hydraulic system. Refer to the procedures indicated: «MASTER CYLINDER REPLACEMENT»(ref-652242-S03105739522014082300000) «FRONT BRAKE HOSE REPLACEMENT»(ref-652242-S25000625212014082300000) «REAR BRAKE HOSE REPLACEMENT»(ref-652242-S13912318132014082300000) «FRONT BRAKE CALIPER REPLACEMENT»(ref-652270-S15074589882014082300000) «REAR BRAKE CALIPER REPLACEMENT»(ref-652270-S38159151262014082300000) «BRAKE PRESSURE MODULATOR VALVE REPLACEMENT»(ref-652262-S20011013052014082300000) Clean out all the hydraulic brake pipes using denatured alcohol, or equivalent. Dry the brake pipes using non-lubricated, filtered air. Repair or replace ALL of the following components listed and install them to the vehicle. Each component contains internal rubber seals/linings which have been contaminated by the contaminated brake fluid in the brake hydraulic system. Refer to the procedures indicated: «MASTER CYLINDER REPLACEMENT»(ref-652242-S03105739522014082300000) ; also perform the following: Clean the brake master cylinder reservoir using denatured alcohol, or equivalent, then dry the reservoir using non-lubricated, filtered air. Inspect the reservoir for cracks and/or damage and replace if necessary. Refer to «MASTER CYLINDER RESERVOIR REPLACEMENT»(ref-652242-S22243456042014082300000) . Replace the brake master cylinder reservoir cap diaphragm. «FRONT BRAKE HOSE REPLACEMENT»(ref-652242-S25000625212014082300000) «REAR BRAKE HOSE REPLACEMENT»(ref-652242-S13912318132014082300000) «FRONT BRAKE CALIPER REPLACEMENT»(ref-652270-S15074589882014082300000) «REAR BRAKE CALIPER OVERHAUL»(ref-652270-S36318931632014082300000) or «REAR BRAKE CALIPER REPLACEMENT»(ref-652270-S38159151262014082300000) «BRAKE PRESSURE MODULATOR VALVE REPLACEMENT»(ref-652262-S20011013052014082300000)
  4. If the brake fluid was NOT contaminated with an oil-based or a silicone-based substance, but WAS contaminated with water or dirt, rust, corrosion, and/or brake dust, replace the brake master cylinder reservoir cap diaphragm. The diaphragm may have allowed the moisture or particles to enter the hydraulic system.
  5. Fill the brake master cylinder reservoir to the maximum-fill level with approved brake fluid from a clean, sealed brake fluid container as specified in the owners manual.
  6. Pressure bleed the hydraulic brake system. Begin the procedure with the pressure bleeder reservoir filled to the maximum-fill level with the correct brake fluid as indicated. Refer to «HYDRAULIC BRAKE SYSTEM BLEEDING (MANUAL)»(ref-652242-S26496361782014082300000) or «HYDRAULIC BRAKE SYSTEM BLEEDING (PRESSURE)»(ref-652242-S15656701082014082300000) .

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Scheme 78: Removal Procedure
Scheme 78: Removal Procedure

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Scheme 81
  1. Remove the left side instrument panel insulator panel. Refer to «INSTRUMENT PANEL INSULATOR PANEL REPLACEMENT - LEFT SIDE»(ref-652235-S07721948282014082300000) .
  2. Disconnect the brake pedal position sensor electrical connector.
  3. NOTE: Do not reuse the power vacuum brake booster pushrod retainer. Release the power vacuum brake booster pushrod retainer (1) from the brake pedal arm by pulling the brake pedal rearward.
  4. Discard the power vacuum brake booster pushrod retainer.
  5. Disconnect the brake fluid level indicator switch electrical connector.
  6. Remove the master cylinder (1) and the master cylinder O-ring seal (2). Refer to «MASTER CYLINDER REPLACEMENT»(ref-652242-S03105739522014082300000) .
  7. Disconnect the power brake booster vacuum sensor (1) electrical connector.
  8. Remove the power brake booster vacuum sensor and hose assembly and position aside.
  9. Remove the brake pressure modulator valve (BPMV) assembly. Refer to «BRAKE PRESSURE MODULATOR VALVE REPLACEMENT»(ref-652262-S20011013052014082300000) .
  10. NOTE: The power vacuum brake booster bolts are captured and withdraw with the power vacuum brake booster assembly. Completely loosen the power vacuum brake booster bolts (1).
  11. Remove the power vacuum brake booster.
  12. Inspect the power vacuum brake booster gasket for damage. Replace it if necessary.

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Scheme 82: Installation Procedure
Scheme 82: Installation Procedure

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Scheme 85
  1. Position the power vacuum brake booster gasket to the power vacuum brake booster, if removed.
  2. Install the power vacuum brake booster.
  3. Refer to «CAUTION: RETAINER»(ref-652229-S20487768742014082300000) . NOTE: Do not over tighten the power vacuum brake booster bolts. If the power vacuum brake booster bolts are over tightened, the brake pedal may remain applied after a high pressure brake pedal application. Tighten the power vacuum brake booster bolts (1) to 23 Nm (17 lb ft).
  4. Install the brake pressure modulator valve (BPMV) assembly. Refer to «BRAKE PRESSURE MODULATOR VALVE REPLACEMENT»(ref-652262-S20011013052014082300000) .
  5. NOTE: A small amount of denatured alcohol may be used to ease installation of the power brake booster vacuum sensor. Do not use soap. Install the power brake booster vacuum sensor and hose assembly (1).
  6. Connect the power brake booster vacuum sensor electrical connector.
  7. Install the master cylinder (1) and master cylinder O-ring seal (2). Refer to «MASTER CYLINDER REPLACEMENT»(ref-652242-S03105739522014082300000) .
  8. Connect the brake fluid level indicator switch electrical connector.
  9. NOTE: Install a new power vacuum brake booster pushrod retainer. Install a new power vacuum brake booster pushrod retainer (1) to the power vacuum brake booster pushrod.
  10. NOTE: Ensure the power vacuum brake booster pushrod retainer is fully seated in the brake pedal arm. Install the power vacuum brake booster pushrod and retainer to the brake pedal arm.
  11. Connect the brake pedal position sensor electrical connector.
  12. Calibrate the brake pedal position sensor. Refer to «BRAKE PEDAL POSITION SENSOR CALIBRATION»(ref-652253-S24781064862014082300000) .
  13. Install the left side instrument panel insulator panel. Refer to «INSTRUMENT PANEL INSULATOR PANEL REPLACEMENT - LEFT SIDE»(ref-652235-S07721948282014082300000) .

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Scheme 86: Removal Procedure
Scheme 86: Removal Procedure

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Scheme 88

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Scheme 89
  1. With the engine OFF, apply and release the brake pedal several times until the brake pedal becomes firm to deplete the power vacuum brake booster vacuum reserve.
  2. Remove the intake manifold cover. Refer to «INTAKE MANIFOLD COVER REPLACEMENT»(ref-652231-S15941694392014082300000) .
  3. NOTE: Lift the dash panel insulator slightly to remove the upper master cylinder heat shield nut. If equipped with the master cylinder heat shield, remove the master cylinder heat shield nuts (1).
  4. Remove the master cylinder heat shield bolt (1).
  5. Remove the master cylinder heat shield.
  6. Disconnect the power vacuum brake booster vacuum sensor electrical connector.
  7. Remove the vacuum sensor (1) and power brake booster vacuum hose assembly from the power vacuum brake booster.
  8. Release the spring clamp (1) and remove the power brake booster vacuum hose from the intake manifold vacuum port.
  9. Release the power brake booster vacuum hose from the routing clip (2) on the power brake booster auxiliary pump.
  10. Disconnect the power brake booster vacuum hose quick connect (3).
  11. Remove the power brake booster vacuum hose and check valve assembly.

Scheme 90

Scheme 90: Installation Procedure
Scheme 90: Installation Procedure

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Scheme 92

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Scheme 93
  1. Install the power brake booster vacuum hose and check valve assembly.
  2. NOTE: A small amount of denatured alcohol may be used to ease assembly. Do not use soap. Position the power brake booster vacuum hose to the intake manifold vacuum port and install the spring clamp (1).
  3. Install the power brake booster vacuum hose to the routing clip (2) on the power brake booster auxiliary pump.
  4. Connect the power brake booster vacuum hose quick connect (3).
  5. NOTE: A small amount of denatured alcohol may be used to ease assembly. Do not use soap. Install the vacuum sensor (1) and power brake booster vacuum hose assembly to the power vacuum brake booster.
  6. Connect the power brake booster vacuum sensor electrical connector.
  7. Install the master cylinder heat shield, if equipped.
  8. Refer to «CAUTION: RETAINER»(ref-652229-S20487768742014082300000) . Install the master cylinder heat shield bolt (1) and tighten to 10 Nm (89 lb in).
  9. NOTE: Lift the dash panel insulator slightly to remove the upper master cylinder heat shield nut. Install the master cylinder heat shield nuts (1) and tighten to 25 Nm (18 lb ft).
  10. Install the intake manifold cover. Refer to «INTAKE MANIFOLD COVER REPLACEMENT»(ref-652231-S15941694392014082300000) .

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Scheme 94: Removal Procedure
Scheme 94: Removal Procedure

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Scheme 98
  1. With the engine OFF, apply the brake pedal several times until the brake pedal becomes firm to deplete the vacuum brake booster vacuum reserve.
  2. Remove the intake manifold cover. Refer to «INTAKE MANIFOLD COVER REPLACEMENT»(ref-652231-S15941694392014082300000) .
  3. Remove the power brake booster vacuum sensor. Refer to «POWER BRAKE BOOSTER VACUUM SENSOR REPLACEMENT»(ref-652242-S06471394112014082300000) .
  4. Release the power vacuum brake booster hose quick connects (1) at the engine.
  5. Release the power vacuum brake booster hose from the retainers (1) on the dash panel.
  6. In the engine compartment, release the power vacuum brake booster hose from the retainer (1) on the right side rail.
  7. Raise and support the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-652230-S26645367622014082300000) .
  8. Remove the radiator air lower deflector. Refer to «RADIATOR AIR LOWER DEFLECTOR REPLACEMENT»(ref-652246-S08001852322014082300000) .
  9. Release the power vacuum brake booster hose from the retainer (1).
  10. Located ahead of the right front wheelhouse liner, release the power vacuum brake booster quick connect (1) and disconnect the hose from the auxiliary pump fitting.
  11. Release the power vacuum brake booster hose retainer (2).
  12. Remove the power vacuum brake booster check valve and hose assembly.

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Scheme 99: Installation Procedure
Scheme 99: Installation Procedure

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Scheme 103
  1. Located ahead of the right front wheelhouse liner, connect the power vacuum brake booster quick connect (1).
  2. Install the power vacuum brake booster hose to the retainer (2).
  3. Install the power vacuum brake booster hose to the retainer (1).
  4. Install the radiator air lower deflector. Refer to «RADIATOR AIR LOWER DEFLECTOR REPLACEMENT»(ref-652246-S08001852322014082300000) .
  5. Lower the vehicle.
  6. In the engine compartment, install the power vacuum brake booster hose to the retainer (1) on the right side rail.
  7. Install the power vacuum brake booster hose to the retainers (1) on the dash panel.
  8. Connect the power vacuum brake booster hose quick connects (1) at the engine.
  9. Install the power brake booster vacuum sensor. Refer to «POWER BRAKE BOOSTER VACUUM SENSOR REPLACEMENT»(ref-652242-S06471394112014082300000) .
  10. Install the intake manifold cover. Refer to «INTAKE MANIFOLD COVER REPLACEMENT»(ref-652231-S15941694392014082300000) .

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Scheme 104: Removal Procedure
Scheme 104: Removal Procedure

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Scheme 106
  1. With the engine OFF, apply and release the brake pedal several times until the brake pedal becomes firm to deplete the power vacuum brake booster vacuum reserve.
  2. NOTE: Lift the dash panel insulator slightly to remove the upper master cylinder heat shield nut. If equipped with the master cylinder heat shield, remove the master cylinder heat shield nuts (1).
  3. Remove the master cylinder heat shield bolt (1).
  4. Remove the master cylinder heat shield.
  5. Disconnect the power vacuum brake booster vacuum sensor electrical connector.
  6. Remove the vacuum sensor (1) and power brake booster vacuum hose assembly from the power vacuum brake booster.
  7. Release the spring clamp and remove the power brake booster vacuum sensor from the vacuum hose.

Scheme 107

Scheme 107: Installation Procedure
Scheme 107: Installation Procedure

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Scheme 108

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Scheme 109
Scheme 109
  1. NOTE: A small amount of denatured alcohol may be used to ease assembly. Do not use soap. Install the power brake booster vacuum sensor (1) to the vacuum hose.
  2. Secure the spring clamp to the vacuum hose.
  3. Connect the power brake booster vacuum sensor electrical connector.
  4. Install the master cylinder heat shield, if equipped.
  5. Refer to «CAUTION: RETAINER»(ref-652229-S20487768742014082300000) . Install the master cylinder heat shield bolt (1) and tighten to 10 Nm (89 lb in).
  6. NOTE: Lift the dash panel insulator slightly to remove the upper master cylinder heat shield nut. Install the master cylinder heat shield nuts (1) and tighten to 25 Nm (18 lb ft).

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Scheme 110: Removal Procedure
Scheme 110: Removal Procedure

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Scheme 112

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Scheme 113
  1. With the engine OFF, apply and release the brake pedal several times until the brake pedal becomes firm to deplete the power vacuum brake booster vacuum reserve.
  2. Remove the intake manifold cover. Refer to «INTAKE MANIFOLD COVER REPLACEMENT»(ref-652231-S15941694392014082300000) .
  3. Disconnect the power brake booster vacuum hose quick connect (3).
  4. Release the power brake booster vacuum hose from the routing clip (2) on the power brake booster auxiliary pump.
  5. Disconnect the power brake booster auxiliary pump electrical connector.
  6. Release the power brake booster auxiliary pump electrical connector retainer from the pump bracket.
  7. Remove the power brake booster auxiliary pump nuts (1).
  8. Remove the power brake booster auxiliary pump.
  9. If removing the power brake booster auxiliary pump bracket, remove the power brake booster auxiliary pump bracket bolts (1).
  10. Remove the power brake booster auxiliary pump bracket (1).

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Scheme 114: Installation Procedure
Scheme 114: Installation Procedure

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Scheme 117
  1. If removed, install the power brake booster auxiliary pump bracket (1).
  2. Refer to «CAUTION: RETAINER»(ref-652229-S20487768742014082300000) . Install the power brake booster auxiliary pump bolts (1) and tighten to 50 Nm (37 lb ft).
  3. Install the power brake booster auxiliary pump to the pump bracket.
  4. Install the power brake booster auxiliary pump nuts (1) and tighten to 9 Nm (80 lb in)
  5. Connect the power brake booster vacuum hose quick connect (3).
  6. Connect the power brake booster auxiliary pump electrical connector.
  7. Secure the power brake booster auxiliary pump electrical connector retainer to the pump bracket.
  8. Secure the power brake booster vacuum hose from the routing clip (2) on the power brake booster auxiliary pump.
  9. Install the intake manifold cover. Refer to «INTAKE MANIFOLD COVER REPLACEMENT»(ref-652231-S15941694392014082300000) .

Scheme 118

Scheme 118: Removal Procedure
Scheme 118: Removal Procedure

Scheme 119

Scheme 119
Scheme 119

Scheme 120

Scheme 120
Scheme 120
  1. With the engine OFF, apply the brake pedal several times until the brake pedal becomes firm to deplete the vacuum brake booster vacuum reserve.
  2. Raise and support the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-652230-S26645367622014082300000) .
  3. Remove the radiator air lower deflector. Refer to «RADIATOR AIR LOWER DEFLECTOR REPLACEMENT»(ref-652246-S08001852322014082300000) .
  4. Located ahead of the right front wheelhouse liner, disconnect the power brake booster auxiliary pump electrical connector.
  5. Release the vacuum hose quick connect and disconnect the hose from the auxiliary pump.
  6. Remove the power brake booster auxiliary pump nuts (1).
  7. Remove the power brake booster auxiliary pump (1) from the bracket.
  8. If removing the power brake booster auxiliary pump bracket, remove the power brake booster auxiliary pump bracket bolts (1).
  9. Remove the power brake booster auxiliary pump bracket.

Scheme 121

Scheme 121: Installation Procedure
Scheme 121: Installation Procedure

Scheme 122

Scheme 122
Scheme 122

Scheme 123

Scheme 123
Scheme 123
  1. If removed, install the power brake booster auxiliary pump bracket.
  2. Refer to «CAUTION: RETAINER»(ref-652229-S20487768742014082300000) . Install the power brake booster auxiliary pump bracket bolts (1) and tighten to 9 Nm (80 lb in).
  3. Install the power brake booster auxiliary pump (1) to the bracket.
  4. Install the power brake booster auxiliary pump nuts (1) and tighten to 9 Nm (80 lb in).
  5. Install the vacuum hose quick connect to the auxiliary pump.
  6. Connect the power brake booster auxiliary pump electrical connector.
  7. Install the radiator air lower deflector. Refer to «RADIATOR AIR LOWER DEFLECTOR REPLACEMENT»(ref-652246-S08001852322014082300000) .

Scheme 124

Scheme 124: Hydraulic Brakes
Scheme 124: Hydraulic Brakes

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