replacing brake booster

2002 CHEVROLET TRAILBLAZER

167,000 MILES • 6 CYL • 4WD • AUTOMATIC

MS. LISA

MEMBER
2 POSTS

Vehicle has no brakes after changing the brake booster, adding new lines, recap brake fluid, bled, and fairly new master cylinder. The brakes goes right to the floor and you hear air. Can someone help me?

Jul 28, 2019 at 5:06 AM

SCGRANTURISMO

✓ASE Certified Mechanic
4,897 POSTS

Hello,

This could be a problem with the vacuum hose going to your brake booster or the brake booster check valve. In the diagrams down below I have included a factory diagnostic troubleshooting flowchart for your vehicle's brake assist system as well as instructions for the removal and installation of the vacuum brake boost check valve and hose. Please go through these guides and get back to us with what you are able to find out.

Thanks,
Alex
2CarPros

Images (Click to enlarge)

Professional Diagram for 2CarPros Members
Click here to log in and view diagram.

Feb 24, 2021 at 7:47 PM

MS. LISA

MEMBER
2 POSTS

I will check. thank you

Feb 24, 2021 at 7:47 PM

STRAILER

✓ASE Certified Mechanic
54,832 POSTS

If I can jump in here. does this car have ABS? if so you may need to have the ABS valve opened using a scan tool while bleeding to get the air out. This guide can help as well:

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

Please run down this guide and report back.

Feb 24, 2021 at 7:47 PM