Buick Regal: Brake Master Cylinder Replacement

Removal Procedure

WARNING: Brake Fluid Irritant Warning.

CAUTION: Brake Fluid Effects on Paint and Electrical Components Caution.

1. Place the ignition switch in the OFF position.

2. Apply and release the brake pedal several times until the brake pedal becomes firm to deplete the power vacuum brake booster vacuum reserve.

3. Without draining the coolant and without disconnecting the hoses, position aside the radiator surge tank.

4. Disconnect the brake fluid level sensor electrical connector.

5.

Master Cylinder Secondary Brake Pipe Fitting (1) - Disconnect.

6. Cap the brake pipe fitting and plug the brake master cylinder outlet port to prevent brake fluid loss and contamination.

7.

Master Cylinder Primary Brake Pipe Fitting (1) - Disconnect.

8. Cap the brake pipe fitting and plug the brake master cylinder outlet port to prevent brake fluid loss and contamination.

9.

NOTE: Do NOT reuse the master cylinder nuts.

Master Cylinder Nut (1) - Remove and DISCARD[2x].

10.

Master Cylinder (1) - Remove.

11.

Brake Master Cylinder Seal (1) - Remove and DISCARD.

Installation Procedure

1.

NOTE: Install a NEW seal.

Brake Master Cylinder Seal (1) - Install.

2.

Master Cylinder (1) - Install.

3.

CAUTION: Fastener Caution.

NOTE: Install NEW nuts.

Master Cylinder Nut (1) - Install and tighten55 N.m (41 lb ft)[2x].

4.

Master Cylinder Primary Brake Pipe Fitting (1) - Install and tighten32 N.m (24 lb ft).

5.

Master Cylinder Secondary Brake Pipe Fitting (1) - Install and tighten32 N.m (24 lb ft).

6. Connect the brake fluid level sensor electrical connector.

7. Radiator Surge Tank Replacement - Install.

8. Bleed the brake system.

BRAKE MASTER CYLINDER BENCH BLEEDING

1.

WARNING: Refer to Brake Fluid Irritant Warning.

CAUTION: Refer to Brake Fluid Effects on Paint and Electrical Components Caution.

Secure the mounting flange of the brake master cylinder in a bench vise so that the rear of the primary piston is accessible.

2. Remove the master cylinder reservoir cap and diaphragm.

3. Install suitable fittings to the master cylinder ports that match the type of flare seat required and also provide for hose attachment.

4. Install transparent hoses to the fittings installed to the master cylinder ports, then route the hoses into the master cylinder reservoir.

5. Fill the master cylinder reservoir to at least the half-way point with GM approved brake fluid from a clean, sealed brake fluid container.

6. Ensure that the ends of the transparent hoses running into the master cylinder reservoir are fully submerged in the brake fluid.

7. Using a smooth, round-ended tool, depress and release the primary piston as far as it will travel, a depth of about 25 mm (1 in), several times. Observe the flow of fluid coming from the ports.

As air is bled from the primary and secondary pistons, the effort required to depress the primary piston will increase and the amount of travel will decrease.

8. Continue to depress and release the primary piston until fluid flows freely from the ports with no evidence of air bubbles.

9. Remove the transparent hoses from the master cylinder reservoir.

10. Install the master cylinder reservoir cap and diaphragm.

11. Remove the fittings with the transparent hoses from the master cylinder ports. Wrap the master cylinder with a clean shop cloth to prevent brake fluid spills.

12. Remove the master cylinder from the vise.

BRAKE FLUID LEVEL SENSOR REPLACEMENT

Removal Procedure

1. Without draining the coolant and without disconnecting the hoses, position aside the radiator surge tank.

2. Disconnect the brake fluid level sensor electrical connector.

3.

Using an appropriate tool, lift upward to release the brake fluid level sensor locking tab (1).

4.

Brake Fluid Level Sensor(1) - Remove.

Installation Procedure

1.

Brake Fluid Level Sensor(1) - Install.

2.

Ensure the brake fluid level sensor locking tab (1) is fully engaged.

3. Connect the brake fluid level sensor electrical connector.

4. Radiator Surge Tank Replacement - Install.

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