Pulsating brake pedal

I just replaced the front brake pads in my car. I did not replace nor
resurface the rotors. Now the brake pedal is pulsating/vibrating
everytime I apply the brakes. This is more noticeable at high speeds.
Can someone offer any suggestions as to why this may be happening? My
understanding is that if the brake pedal pulsates and the steering
vibrates while braking, then this indicates bad rotors. But in my case
the steering wheel *does not* vibrate, its only the brake pedal that is
pulsating.

I also read somewhere that another cause for this could be the rear
brakes. I had replaced my rear brake pads about 6-9 months ago (didn't
resurface the rear rotors, just replaced pads). So my rear brakes
should be good. My brake pedal was not pulsating prior to replacing the
front pads.

Your inputs are appreciated.
Thanks,
Mark

sounds like a warped rotor, suggest having them turned.

Mark wrote:
> My brake pedal was not pulsating prior to
> replacing the front pads.

Did you remove the rotors from their hub during the procedure or let
them "fall away" from the hub while replacing the pads?

You may have had rust particles come loose from the rotor and get
jammed between the rotor and hub causing it to not seat squarely --
hence the magical new vibration. Likewise the rotor could simply not
be fully seated (cocked) which can be a very dangerous safety issue.

Or you could have removed the rotor and installed it in a different
position index as referenced to the hub -- stacked run-out tolerances
could be worse now than in the original position.

Or you could have overtightened or unevenly tightened the lugnuts.

If you were to mention your year, make, and model then more specific
experience based answers might come of it.

Toyota MDT in MO

If you got the wheel lug nuts on at different torques, that can cause
the rotors to warp and the pedal to pulse. With most of the cheap
rotors these days, you really need a hand torque wrench to put the
wheels on or you end up with problems.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Mark wrote:
>
> I just replaced the front brake pads in my car. I did not replace nor
> resurface the rotors. Now the brake pedal is pulsating/vibrating
> everytime I apply the brakes. This is more noticeable at high speeds.
> Can someone offer any suggestions as to why this may be happening? My
> understanding is that if the brake pedal pulsates and the steering
> vibrates while braking, then this indicates bad rotors. But in my case
> the steering wheel *does not* vibrate, its only the brake pedal that is
> pulsating.
>
> I also read somewhere that another cause for this could be the rear
> brakes. I had replaced my rear brake pads about 6-9 months ago (didn't
> resurface the rear rotors, just replaced pads). So my rear brakes
> should be good. My brake pedal was not pulsating prior to replacing the
> front pads.
>
> Your inputs are appreciated.
> Thanks,
> Mark

Comboverfish wrote:

>
>
> Mark wrote:
> > My brake pedal was not pulsating prior to
> > replacing the front pads.
>
> Did you remove the rotors from their hub during the procedure or let
> them "fall away" from the hub while replacing the pads?
>
> You may have had rust particles come loose from the rotor and get
> jammed between the rotor and hub causing it to not seat squarely --
> hence the magical new vibration. Likewise the rotor could simply not
> be fully seated (cocked) which can be a very dangerous safety issue.
>
> Or you could have removed the rotor and installed it in a different
> position index as referenced to the hub -- stacked run-out tolerances
> could be worse now than in the original position.
>
> Or you could have overtightened or unevenly tightened the lugnuts.
>
> If you were to mention your year, make, and model then more specific
> experience based answers might come of it.
>
> Toyota MDT in MO



http://www.babcox.com/editorial/bf/bf100326.htm

"Mike Romain" > wrote in message
...
> If you got the wheel lug nuts on at different torques, that can cause
> the rotors to warp and the pedal to pulse. With most of the cheap
> rotors these days, you really need a hand torque wrench to put the
> wheels on or you end up with problems.
>
> Mike

You can say that again. Some are extremely sensitive.
I had my tires rotated not long ago at a wellknown national Discount Tire
store.
They claim to use torque stick impact wrenches just to run up the lug nuts,
and then take them
the rest of the way by hand. I watched as they did it, actually, and
thought this might be an
okay way to do it. It wasn't.

Rotors warped very quickly. If those torque sticks allow overtorqueing to
begin with, then
the kid pulling the manual torque wrench is unlikely to notice the problem.
I learned another
good lesson that day.