Brakes

2006 CHEVROLET SILVERADO
180,000 MILES • 5.3L • V8 • 4WD • AUTOMATIC
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KJANES389
  • MEMBER
  • 2 POSTS
Service brake booster warning comes on but my brake pedal is hard and holding also when I pull the check valve on the booster it sucks in air and if I pull the hose while it’s running it runs really rough. Is there any test you can do on the booster to check it or how to I get rid of that warning? Brakes work fine
Nov 26, 2023 at 3:07 PM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.
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JACOBANDNICKOLAS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 110,190 POSTS
Hi,

When you remove the hose, you are creating a large vacuum leak. That is why the engine runs really poorly. As far as testing, the brake booster is a vacuum operated device. The way to check them is by applying a vacuum to them with a vacuum pump (with a gauge) and seeing if the pressure drops.

By chance, have you tried checking if there are diagnostic trouble codes? Also, there is a vacuum pump mounted on the booster. Do you notice if it is working?

Do me a favor. Take a look at the picture I attached below. Let me know if that is what you are seeing on your truck. I ask because based on your description, it sounds like you have a vacuum assist brake booster. However, they also used what is called a Hydro Boost system on some of these. Brake assist is done by the power steering pump.

Let me know.

joe

See pic below.
Image (Click to enlarge)
Attached Media
Nov 27, 2023 at 8:37 PM
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