Hydraulic brake booster (Chevrolet Tahoe 2)

Contents: Examination ↧ Removal and installation ↧

Examination

Caution: The hydraulic booster may appear wet due to excess fluid when installed at the factory or due to brake fluid spillage when filling the system. Check for leaks before deciding to replace the booster.

Note: The hydraulic brake system uses two different and incompatible fluids. The hydraulic brake booster uses power steering fluid. The rest of the system uses brake fluid. Do not mix the fluids when servicing.

1. Check the condition of the working fluid in the power steering system, adjust the fluid level if necessary.

2. Clean the amplifier parts:

body near the fittings (3) and the fittings;
place (2) of installation on the brake master cylinder booster;
end cap;
place (1) for installing the amplifier on the end cap.

place (1) for installing the amplifier on the end cap.

Note: To properly diagnose leaks, you may need the assistance of an assistant.

3. Start the engine and warm up the power steering fluid to operating temperature.

4. With the engine idling, slowly press the pedal until the pressure relief valve of the power steering pump operates (a hissing sound occurs). Hold the pedal in this position for approximately two seconds and release the brake pedal.

5. Let the engine idle for 15 seconds without pressing the brake pedal.

6. Repeat steps 4 and 5 four more times.

7. With the engine idling, turn the steering wheel from lock to lock four times, holding the wheel at each lock for 2 seconds.

Caution: Do not hold the steering wheel on the stop for more than three seconds, otherwise the working fluid may overheat.

8. Bring the engine to about 1000 rpm and turn the steering wheel from lock to lock six times at a rate of one revolution per second. Do not hold the steering wheel at the lock.

9. Let the engine idle for 30 seconds without pressing the brake pedal.

10. With the engine idling, press the brake pedal until the power steering pump relief valve operates, hold the pedal for one second and release the pedal. _

11. Repeat steps 7-10 four times.

12. Let the engine idle and turn it off after 30 seconds.

13. Inspect the hydraulic booster, look for leaks.

Attention:

On low mileage vehicles, a light film of liquid may form between the booster and the end cap. If a drip leak occurs, replace the booster.

A leak between the brake booster and the brake master cylinder is not acceptable. If there is fluid at the connector, determine the type of fluid. If it is power steering fluid, replace the brake booster. If it is brake fluid, there is a problem with the brake master cylinder.

Removal and installation

1. Apply the parking brake and block the wheels.

2. Disconnect the inlet hose, steering gear hose and return hose from the brake booster.

3. Loosen the nuts securing the brake cylinder to the booster and move the master cylinder to the side.