Brake System Slow Release. Buick GL7 (Export) 2000

For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Hydraulic Brake Diagnostic System Check performed? | -- | Go to Step 2 | Go to Hydraulic Brake Diagnostic System Check

2

Check the park brake lever for proper operation by doing the following:

1. Turn the ignition ON.
2. Press the park brake pedal until it stops. Verify the Brake Warning Lamp is ON.
3. Pull the park brake release lever. Verify the Brake Warning Lamp is OFF.

Did the park brake warning lamp turn OFF and the pedal return to its original height?

--

Go to Step 4

Go to Step 3

3

1. Check the park brake assembly for interference, binding or for broken components.
2. Lubricate the park brake assembly.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

4

1. Start the engine.
2. Shift the vehicle into DRIVE.
3. Attempt to move the vehicle by slowly pressing the accelerator pedal.

Does the engine speed increase without the vehicle moving?

--

Go to Step 5

Go to Step 7

5 | Inspect the park brake cables for corrosion, kinks, or interference with other components. Are the park brake cables corroded, kinked, or interfering with other components? | -- | Go to Step 6 | Go to Step 7
6 | Realign or replace the park brake cable(s) as necessary. Refer to Parking Brake Front Cable Replacement , Parking Brake Rear Cable Replacement - Left Side and Parking Brake Rear Cable Replacement - Right Side in Park Brake. Is the repair complete? | -- | Go to Hydraulic Brake Diagnostic System Check | --

7

1. Remove the brake drum.
2. Inspect the brake linings for the following:

• | Excessive wear

• | Uneven wear

• | Abuse

• | Glazing

• | Contaminated lining material

• | Incorrect lining material

Refer to Brake Shoe Inspection in Drum Brakes.

Do any of the above conditions exist?

--

Go to Step 8

Go to Step 9

8 | Replace the brake shoe linings. Refer to Brake Shoe Replacement in Drum Brakes. Is the repair complete? | -- | Go to Hydraulic Brake Diagnostic System Check | --
9 | Inspect the brake shoe mounting hardware and springs for corrosion or binding. Is the mounting hardware or springs corroded or binding? | -- | Go to Step 10 | Go to Step 11
10 | Replace the mounting hardware or springs as necessary. Is the repair complete? | -- | Go to Hydraulic Brake Diagnostic System Check | --
11 | Inspect the park brake lever for corrosion and free movement without binding. Does the park brake lever bind? | -- | Go to Step 12 | Go to Step 13
12 | Clean the park brake lever components and check for proper movement. If the park brake lever still does not move freely, replace the park brake lever. Refer to Park Brake Lever Assembly Replacement in Park Brake. Is the repair complete? | -- | Go to Hydraulic Brake Diagnostic System Check | --
13 | Inspect the disc brake caliper mounting bolts for corrosion. Refer to Brake Pad Inspection in Disc Brakes. Are the sleeves or mounting bolts corroded? | -- | Go to Step 14 | Go to Step 15
14 | Replace the mounting bolt sleeves and bolts as necessary. Is the repair complete? | -- | Go to Hydraulic Brake Diagnostic System Check | --

15

1. Remove the caliper piston. Refer to Front Brake Caliper Overhaul or Rear Brake Caliper Overhaul in Disc Brakes.
2. Inspect the caliper bore and the piston for scoring, corrosion, plating damage or pitting.

Is there damage to the piston or caliper bore?

--

Go to Step 16

Go to Step 17

16 | Replace the piston or the caliper as needed. Is the repair complete? | -- | Go to Hydraulic Brake Diagnostic System Check | --

17

1. Inspect the brake pedal assembly for bent or misaligned components.
2. Inspect the brake pedal for interference (binding) between the pedal and the booster input rod.

Is the brake pedal binding?

--

Go to Step 18

Go to Step 19

18 | Disassemble and realign or replace components as necessary. Is the repair complete? | -- | Go to Hydraulic Brake Diagnostic System Check | --

19

Check the brake pedal for interference with other components. Inspect the brake pedal area for the following:

• | Loose or misaligned trim panels

• | Loose components, wiring harnesses or aftermarket devices

Are there any loose or interfering components?

--

Go to Step 20

Go to Step 21

20 | Realign or reposition components as necessary. Is the repair complete? | -- | Go to Hydraulic Brake Diagnostic System Check | --

21

• | Check for collapsed, damaged, or bent brake pipes.

• | Check the brake hoses for sharp kinks.

Are the brake hoses or the brake pipes collapsed, bent, or kinked?

--

Go to Step 22

Go to Step 23

22 | Reroute or replace the brake hoses or pipes as necessary. Is the repair complete? | -- | Go to Hydraulic Brake Diagnostic System Check | --

23

1. Remove the master cylinder reservoir cover.
2. Rapidly apply the brake pedal 3 cm (1 in), observing the brake fluid in the reservoir.

Does the fluid surface in the forward reservoir show movement, or spouting?

--

Go to Step 24

Go to Step 25

24

1. Install the master cylinder reservoir cover.
2. Loosen the master cylinder mounting nuts 13 mm (0.50 in).
3. Separate the master cylinder from the vacuum brake booster.
4. Apply the brake pedal 3 cm (1 in).

Does the booster output rod move?

--

Go to Step 27

Go to Step 26

25 | Replace the master cylinder. Refer to Brake Modulator/Master Cylinder Assembly Replacement in Antilock Brake System. Is the repair complete? | -- | Go to Hydraulic Brake Diagnostic System Check | --
26 | Replace the vacuum brake booster. Refer to Power Vacuum Brake Booster Replacement . Is the repair complete? | -- | Go to Hydraulic Brake Diagnostic System Check | --

27

1. Remove the master cylinder reservoir cover.
2. Inspect the brake fluid for contamination.

Is the brake fluid contaminated?

--

Go to Step 28

Go to Step 29

28

Replace all of the hydraulic brake system rubber components.

1. Flush the hydraulic brake system. Refer to Hydraulic Brake System Flushing .
2. Replace the ABS modulator. Refer to Brake Modulator/Master Cylinder Assembly Replacement in Antilock Brake System.
3. Repair or replace the master cylinder. Refer to Master Cylinder Overhaul .
4. Replace the TCS modulator. Refer to Traction Control System Modulator/Motor Pack Replacement in Antilock Brake System (if equipped).
5. Replace the front brake hoses. Refer to Front Brake Hose Replacement .
6. Replace the intermediate brake hoses. Refer to Brake Intermediate Hose Replacement
7. Replace the rear brake hoses. Refer to Rear Brake Hose Replacement .
8. Repair or replace the FRONT brake calipers. Refer to Front Brake Caliper Overhaul or Front Brake Caliper Replacement in Disc Brakes.
9. Repair or replace the REAR brake calipers (export only). Refer to Rear Brake Caliper Overhaul or Rear Brake Caliper Replacement in Disc Brakes.
10. Repair or replace the wheel cylinders. Refer toWheel Cylinder Overhaul or Wheel Cylinder Replacement in Drum Brakes.
11. Flush the hydraulic brake system. Refer to Hydraulic Brake System Flushing .

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

29 | Check the master cylinder outlet ports for restricted passages. Refer to Hydraulic Brake System Bleeding . Are the outlet ports restricted? | -- | Go to Step 30 | Go to Step 31

30

1. Replace the master cylinder. Refer to Brake Modulator/Master Cylinder Assembly Replacement in Antilock Brake System.
2. Flush the hydraulic brake system. Refer to Hydraulic Brake System Flushing .

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

31

Check the brake pipes and the brake hoses for restricted passages. Refer to Hydraulic Brake System Flushing .

Check for the following:

• | Low fluid or no fluid output

• | Spurting of fluid while pressing the brake pedal

• | Particles suspended in the fluid

Do any of the above conditions exist?

--

Go to Step 32

Go to Step 33

32

1. Determine the area of the restriction. This will involve the disassembly of individual brake lines and checking for low fluid output.
2. Flush the individual brake line or the brake hose.
3. If the restriction cannot be removed, replace the applicable brake hose or the brake pipe.
4. Flush the hydraulic brake system. Refer to Hydraulic Brake System Flushing .

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

33 | Verify proper brake system operation. Does the original condition still exist? | -- | Go to Step 1 | System OK