GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2000 🢒 Montana 🢒 Brakes 🢒 Hydraulic Brakes 🢒 Brake System Slow Response

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

Inspect the hydraulic brake system for leaks.

Are there any leaks?

--

Go to Step 3

Go to Step 5

3
  1. Tighten the brake hose or pipe fittings to specifications.
  2. Start the engine.
  3. Press the brake pedal several times.
  4. Turn OFF the engine.
  5. Inspect the hydraulic brake system for leaks.

Does the leak still exist?

--

Go to Step 4

Go to Hydraulic Brake Diagnostic System Check

4

Replace the applicable brake hose or the brake pipe.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

5

Inspect the brake linings for the following:

    • Excessive wear
    • Uneven wear
    • Abuse
    • Glazing
    • Contaminated lining material
    • Incorrect lining material

Refer to Brake Pad Inspection in Disc Brakes and Brake Shoe Inspection in Drum Brakes.

Do any of the above conditions exist?

--

Go to Step 6

Go to Step 7

6

Replace the brake linings as necessary. Refer to the applicable procedures.

    •  Front Disc Brake Pads Replacement in Disc Brakes.
    •  Rear Disc Brake Pads Replacement in Disc Brakes.
    •  Brake Shoe Replacement in Drum Brakes.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

7

Inspect the following brake caliper assembly components for corrosion:

    • Mounting bolts
    • Sleeves
    • Steering knuckle
    • Brake caliper
    • Brake caliper pistons

Are any of the above components corroded or binding?

--

Go to Step 8

Go to Step 9

8

Repair or replace the brake calipers. Refer to the applicable repair procedures.

    • For the FRONT brake calipers, refer to Front Brake Caliper Overhaul or Front Brake Caliper Replacement in Disc Brakes.
    • For the REAR brake calipers, refer to Rear Brake Caliper Overhaul or Rear Brake Caliper Bracket Replacement in Disc Brakes.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

9

Inspect the brake components for loose, missing or broken components. Refer to Brake Pad Inspection in Disc Brakes and Brake Shoe Inspection in Drum Brakes.

Are there loose, missing or broken brake components?

--

Go to Step 10

Go to Step 11

10

Repair or replace the components as necessary.

    •  Front Disc Brake Pads Replacement in Disc Brakes.
    •  Rear Disc Brake Pads Replacement in Disc Brakes.
    •  Brake Shoe Replacement in Drum Brakes.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

11
  1. Inspect the wheel cylinder for leakage.
  2. Inspect the wheel cylinder for binding.

Is the wheel cylinder leaking or binding?

--

Go to Step 12

Go to Step 13

12

Repair or replace the wheel cylinder. Refer to Wheel Cylinder Overhaul or Wheel Cylinder Replacement in Drum Brakes.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

13
  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 14

Go to Step 15

14

Repair or replace components as necessary.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

15
  1. Check the brake pedal for interference with other components.
  2. 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 16

Go to Step 17

16

Repair or replace the components as necessary.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

17
  1. Check for collapsed, damaged, or bent brake pipes.
  2. Check the brake hoses for sharp kinks.

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

--

Go to Step 18

Go to Step 19

18

Repair or replace the brake hoses or pipes as necessary.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

19
  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 20

Go to Step 21

20
  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 21

Go to Step 22

21

Replace the master cylinder. Refer to Master Cylinder Replacement in Antilock Brake System.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

22

Replace the vacuum brake booster. Refer to Power Vacuum Brake Booster Replacement .

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

23
  1. Remove the master cylinder reservoir cover.
  2. Inspect the brake fluid for contamination.

Is the brake fluid contaminated?

--

Go to Step 24

Go to Step 25

24

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 Master Cylinder Replacement .
  3. Repair or replace the master cylinder. Refer to Master Cylinder Overhaul .
  4. Replace the front brake hoses. Refer to Front Brake Hose Replacement .
  5. Replace the intermediate brake hoses. Refer to Brake Intermediate Hose Replacement .
  6. Replace the rear brake hoses. Refer to Rear Brake Hose Replacement .
  7. Repair or replace the FRONT brake calipers. Refer to Front Brake Caliper Overhaul or Front Brake Caliper Replacement in Disc Brakes.
  8. Repair or replace the REAR brake calipers (export only). Refer to Rear Brake Caliper Overhaul or Rear Brake Caliper Replacement in Disc Brakes.
  9. Repair or replace the wheel cylinders. Refer to Wheel Cylinder Overhaul or Wheel Cylinder Replacement in Drum Brakes.
  10. Flush the hydraulic brake system. Refer to Hydraulic Brake System Flushing .

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

25

Check the master cylinder outlet ports for restricted passages. Refer to Hydraulic Brake System Bleeding .

Are the outlet ports restricted?

--

Go to Step 26

Go to Step 27

26
  1. Replace the master cylinder. Refer to Master Cylinder Replacement in Hydraulic 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

--

27
  1. Check the brake pipes and the brake hoses for restricted passages. Refer to Hydraulic Brake System Flushing .
  2. 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 apply?

--

Go to Step 28

Go to Hydraulic Brake Diagnostic System Check

28
  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

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