Brake Pedal Travel Gradually Increases. GMC Truck Savana 1999

GM Service Manual Online

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 1999 🢒 Savana 🢒 Brakes 🢒 Hydraulic Brakes 🢒 Brake Pedal Travel Gradually Increases

Step

Action

Value(s)

Yes

Was the Hydraulic Brake Diagnostic System Check performed?

Go to Step 2

Go to Hydraulic Brake Diagnostic System Check

Is the operator riding the brake pedal?

Advise customer of proper braking procedures

Go to Step 3

Inspect the vehicle for overloading.

Is there excessive weight in the vehicle?

Go to Step 4

Go to Step 5

Remove the extra weight from the vehicle.

Does the original condition still exist?

Go to Step 5

Go to Step 19

Inspect the brake pedal assembly for the following:

•	Bent or misaligned components

•	Binding or interference between the pedal and the booster input rod

•	Interference with other components

Are the components misaligned or binding?

Go to Step 6

Go Step 7

Repair or replace the cause of misalignment.

Is the repair complete?

Go to Step 19

Inspect the disc brake pads and brake shoe linings for the following:

•	Excessive wear

•	Uneven wear

•

Abuse

•

Glazing

•	Contaminated lining material

•	Incorrect lining material

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

Do any of the above conditions apply?

Go to Step 8

Go to Step 9

Replace the brake linings. Refer to Brake Pads Replacement in Disc Brakes or Brake Shoe Replacement in Drum Brakes.

Is the repair complete

Go to Step 19

Inspect the brake rotors for the following:

•

Hot spots

•	Scored rotor surface

Do any of the above conditions apply?

Go to Step 10

Go to Step 11

Refinish the brake rotor. Refer to Brake Rotor Refinishing in Disc Brakes.
If refinishing the brake rotor results in a thickness that is less than the thinnest (Refinishing) thickness, replace the rotor. Refer to Refer to Component Specifications in Drum Brakes or Brake Rotor Replacement in Disc Brakes.

Is the repair complete?

Go to Step 19

Inspect the vehicle brake booster for the following:

•

Leaks

•

Damage

•	Restricted passages

Refer to Vacuum Booster Diagnosis - Hard Pedal or Vacuum Booster Diagnosis - Brakes Fail to Release or Hydraulic Booster Noise Diagnosis .

Do any of the above conditions apply?

Go to Step 12

Go to Step 13

Repair or replace the brake booster. Refer to Power Vacuum Brake Booster Replacement or Power Brake Booster Replacement in Hydraulic Brakes.

Is the repair complete?

Go to Step 19

Inspect the vehicle for a leaking master cylinder (internal). Refer to Master Cylinder Diagnosis in Hydraulic Brakes.

Is the master cylinder leaking?

Go to Step 14

Go to Step 15

Overhaul or replace the master cylinder. Refer to Master Cylinder Replacement or Master Cylinder Overhaul .

Is the repair complete?

Go to Step 19

Check for leaking brake pipes, hoses or connections. Refer to Brake Fluid Leak .

Are any of the above components leaking?

Go to Step 16

Go to Step 17

Repair the cause of the leak.

Is the repair complete?

Go to Step 19

Check the brake pipes and hoses for the following:

•	Low fluid or no fluid output

•	Spurting of fluid while pressing the brake pedal

•	Particles suspended in the fluid.

Refer to Hydraulic Brake System Flushing .

Do any of the above conditions apply?

Go to Step 18

Go to Step 19

Determine the area of the restriction. This will involve the disassembly of the individual brake lines and checking for low or no fluid output.
Flush the individual brake line or hose. Refer to Hydraulic Brake System Flushing .
If the restriction cannot be removed, replace the brake hose or pipe as necessary.
Flush the hydraulic brake system. Refer to Hydraulic Brake System Flushing .

Is the repair complete?

Go to Step 19

Verify the proper brake system operation.

Does the original condition still exist?

Go to Step 20

Go to Hydraulic Brake Diagnostic System Check

Verify customer complaint.

Has the customer complaint been verified?

Go to Step 1

Go to Hydraulic Brake Diagnostic System Check