Mark Floyd

Hi all,

I could use help diagnosing an issue on my 2000 Civic GX (84,000 miles, no modifications except for rear and front sway bars)

If I brake while riding over a pothole, or a large dip, I feel a loose/rattle feeling from the brake pedal, and I hear what sounds like a low pitched hum/jostle/rattle -- all of this may be at oscillating frequency (not totally sure yet)

Some more details on my reproduce-able cases:
* Pot hole test involves depressing brake petal before I enter the pothole/dip, and I keep it pressed. I performed this for speeds starting from 20-35mph
* My pothole test involved me braking while riding over a pothole with my passenger side front tire. Firm, moderate, medium-light braking doesn't matter - I still hear the noises and feel the sensation through brake pedal.
* Dip test involved my driveway - I entered driveway braking from a speed of ~15mph.

Mentioning in case it's related -- I've been noticing another rubbing noise in morning when I pull my car out of driveway. I turn the steering wheel far right as I back out, and I hear the rubbing noise as I go forward and my steering wheel straightens back out. Rub is also lower pitched hum noise -- but not a rattle.

any tips on root cause most appreciated.

Thanks.
__________________

kp

Sounds like your ABS is kicking in. This is normal. Have you ever locked up your wheels in the rain/snow? This should be the same pedal feel. It should feel like the brake pedal is pulsing under your foot very rapidly and you should hear a pulsing/clicking noise that corresponds to the pedal.

This happens to me all the time in my Fit when driving over poorly installed manhole covers.

Mark Floyd

Ahhh I see. Thanks for responding.

Is this level of vibration/sound specific to Civic/Fit? I've driven dozens of cars over past 18 years, and this is first time I've heard this noise and feel in the pedal whlie braking.

aw614

I wonder if its the caliper pins? I have a similar noise I've been trying to diagnose on my brother's 2002 civic that doesn't have ABS. I plan on replacing the pins and seeing what happens on it.

Does braking performance feel affected? I thought mine were bad strut bearings at first with the noises I was getting.

kp

Caliper pins simply allow the caliper to float so it stays centered while the brakes are applied. Pins can dry out over time and seize which makes all manner of sounds, but not like what OP has described.