when pressed while running goes all the way to floor ?

2003 CHEVROLET BLAZER
145,000 MILES • 4.3L • 4WD • AUTOMATIC
Avatar
MIKEJUSTIN
  • MEMBER
  • 1 POST
Hard full pedal with engine off, but when pressed while running goes all the way to floor with no resistance. New master cylinder and ABS.
Aug 28, 2018 at 11:45 AM
Advertisement
Avatar
ASEMASTER6371
  • ✓Experienced Mechanic
  • 52,796 POSTS
This happens when the brake booster internal valve goes bad here are diagrams and instructions on how to change it out. Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

Images (Click to enlarge)
Attached Media
Attached Media
Attached Media
Attached Media
Attached Media
Aug 28, 2018 at 7:18 PM
🔧 Tools & Auto Repair Parts
Find automotive tools, diagnostic equipment, and replacement parts for your next repair.
Shop on Amazon →
Paid affiliate link. As an Amazon Associate, we earn from qualifying purchases.
Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Ask a new question

Frequently Asked Problems for This Vehicle