Chevrolet Silverado / GMC Sierra. Service manual — part 2392

14. If the power brake booster is leaking, replace the power brake booster. Refer to Power

Brake Booster Replacement (Adjustable Pedals) or Power Brake Booster
Replacement (Non-Adjustable Pedals).

15. If brake fluid is leaking, refer to Brake Fluid Loss for additional diagnostics.

POWER BRAKE BOOSTER REPLACEMENT (ADJUSTABLE PEDALS)

Fig. 39: Power Brake Booster Replacement (Adjustable Pedals)
Courtesy of GENERAL MOTORS CORP.

Brake fluid indicates an issue with the brake master cylinder.

Callout

Component Name

Preliminary Procedures

NOTE:

Hydraulic brake systems use two distinct and incompatible fluids. Power steering fluid is used in
the hydraulic brake booster system. Brake fluid is used in the master cylinder and brake pipes. Use
extreme care when selecting brake system fluids, or seal damage can result.

2008 Chevrolet Silverado 1500

2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

POWER BRAKE BOOSTER REPLACEMENT (NON-ADJUSTABLE PEDALS)

1. Apply the park brake.

2. Deplete the power reserve in the brake booster by applying the brake pedal several

times until the pedal becomes firm.

3. Without disconnecting the brake pipes, remove and position the brake master cylinder

aside and support with heavy mechanics wire or equivalent. Refer to Master
Cylinder Replacement (JD9, JF3, JF7) or Master Cylinder Replacement (JH6,
JH7).

1

Brake Booster Pushrod Retainer Bolt

Tighten: 10 N.m (89 lb in)

NOTE:

Refer to Fastener Notice .

2

Brake Booster Pushrod Retainer

3

Stop Lamp Switch

4

Power Brake Booster Pushrod

5

Brake Booster Nut (Qty: 4)
Tip: Tighten the upper right power brake booster nut first.

Tighten: 33 N.m (24 lb ft)

6

Power Brake Booster Return Hose Clamp

7

Power Brake Booster Return Hose

8

Power Brake Booster Outlet Hose Fitting

Tighten: 33 N.m (24 lb ft)

9

Power Brake Booster Inlet Hose Fitting

Tighten: 33 N.m (24 lb ft)

10

Power Brake Booster

Procedure

1. Inspect the power brake booster to cowl gasket for damage. Replace if

necessary.

2. Bleed the power steering system. Refer to Power Steering System

Bleeding .

2008 Chevrolet Silverado 1500

2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

Fig. 40: Power Brake Booster Replacement (Non-Adjustable Pedals)
Courtesy of GENERAL MOTORS CORP.

Callout

Component Name

Preliminary Procedures

1. Apply the park brake.

2. Deplete the power reserve in the brake booster by applying the brake pedal several

times until the pedal becomes firm.

3. Without disconnecting the brake pipes, remove and position the brake master cylinder

aside and support with heavy mechanics wire or equivalent. Refer to Master
Cylinder Replacement (JD9, JF3, JF7) or Master Cylinder Replacement (JH6,
JH7).

NOTE:

Hydraulic brake systems use two distinct and incompatible fluids. Power steering fluid is used in
the hydraulic brake booster system. Brake fluid is used in the master cylinder and brake pipes. Use
extreme care when selecting brake system fluids, or seal damage can result.

Brake Booster Pushrod Retainer Bolt

2008 Chevrolet Silverado 1500

2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

HYDRAULIC BRAKE BOOSTER ACCUMULATOR REPLACEMENT

Tools Required

J 26889 Accumulator Piston Compressor. See Special Tools.

Removal Procedure

1

Tighten: 10 N.m (89 lb in)

NOTE:

Refer to Fastener Notice .

2

Brake Booster Pushrod Retainer

3

Stop Lamp Switch

4

Brake Booster Pushrod

5

Brake Booster Nut (Qty: 4)
Tip: Tighten the upper right power brake booster nut first.

Tighten: 33 N.m (24 lb ft)

6

Power Brake Booster Return Hose Clamp

7

Power Brake Booster Return Hose

8

Power Brake Booster Outlet Hose Fitting

Tighten: 33 N.m (24 lb ft)

9

Power Brake Booster Inlet Hose Fitting

Tighten: 33 N.m (24 lb ft)

10

Power Brake Booster

Procedure

1. Inspect the power brake booster gasket for damage. Replace if necessary.

2. Bleed the power steering system. Refer to Power Steering System

Bleeding .

CAUTION: The accumulator contains compressed gas. Always use the

proper tools and follow the recommended procedures or
personal injury may result. Do not apply heat to accumulator.
Do not attempt to repair an inoperative accumulator. Always

2008 Chevrolet Silverado 1500

2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado