1994 GMC Sonoma fluid bypass

1994 GMC SONOMA
250,000 MILES • 6 CYL • 2WD • MANUAL
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JOHN SINGLETON
  • MEMBER
  • 1 POST
have abs on this vehicle have replaced master cylinder no leaking anywhere. when the brake pedal is pushed down there is a hissing sound like the fluid is bypassing or not enough force to completely compress the master cylinder piston. I am not familiar with how the abs module works. could something be stuck in the abs module or do I have a booster problem?
Aug 12, 2010 at 7:16 AM
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BLUELIGHTNIN6
  • ✓ASE Certified Mechanic
  • 16,542 POSTS
  • ASE Certified Mechanic
if certain none of the lines are leaking than check for vacuum leak near the brake booster.
Sep 30, 2010 at 3:54 PM
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