Hey all,

My ABS has been giving me issues for quite awhile now, and haven't been able to diagnose the issue. When I brake over slight bumps in the road (at slow or high speeds), my ABS will kick on, which is definitely not normal.

In addition, my brakes will feel super spongey, but when i complete let off the brake, and brake again, they feel stiffer. Dealership looked at it, replaced the ABS harness, rotors and front brake pads, all to no avail. They suggested replacing the whole assembly (for something like $3500, but w/o guarantees that it will fix it)

Also, when I start the car, there is a very loud buzz at 10 mph. This is likely the ABS motor doing it's startup, but it is really loud. Strangely, when I hit a pothole, a similar sound is made. Could it be something with the suspension?

I am leaning to pulling out the fuse, and seeing if that helps, but would like to keep ABS operational ideally.

 

I had abs acting over speed bumps when my tires had less than 50% thread on them. Spongy pedal means air in the system or failing master cylinder. Later the brake pedal will it will sink to the floor under steady pressure. Jut in case check the rear wheel cylinders (pull the boots slightly) for leaks.

 

Hey DrJ,

Thanks for the quick response. Will looking inoto changing the tires, as they still have good life, but were shitty ones that came when i bought the car used.

The brake pedal does hit the floor under steady pressure. Not always, but at times. There are days where the brakes feel stiff for the whole trip, but most of the time, the brakes are somewhat spongey, so I brake a bit, let off, then brake again to a stop. Do you think i should flush the brake fluid and replace? Is it easy for the dealership to diagnose if the master cylinder is bad? Or is this one of those replace and try it out jobs?

 

When pedal goes to the floor under steady pressure (holding car in "drive" with the brakes) and car tries to move forward with some scraping noise, it is for sure the master cylinder. For your particular case check adjustment of the rear brakes, then bleed the brakes , if no improvement replace the master cylinder

 

Thanks. Will look into this. Also, any clue as to the really loud buzz sound when the car hits 10 mph? It only started getting loud when this issue arose. Never before.

 

This is the tough one (can originate from many places including the exhaust system or suspension) the abs pump rathe rmakes moaning sound