1994 GMC Sonoma 6 cyl Two Wheel Drive Manual 250000 miles
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?