lets say your going 60mph, and you see a deer. with all your leg power, you slam on the brake pedal. how is the car supposed to react. (regular conditions, no rain, 75-80 degrees).

if i want to stop regular (up to 60% pressure on brake pedal) my car stops fine.
but if i slam on the pedal hard, i get this vibration (feel it from the brake pedal itself).
car doesnt stop too well (grinding/vibration like feeling) and sways just alittle.

today, (with tires not really warmed up), i drove upto 50, slammed on brakes, got the usual vibration sensation/bad stoppage, and then abs light came on.

shut down car, restarted, drove off...2 hours later actually felt abs kick in on a stop (no vibration in pedal).

every other time if i need to emergency stop i get this annoying griding feeling.

what gives?

im running mpsc + pagid oranges now. rotors have been replaced 4k miles ago.
stock pads do the same thing exactly.i iniitally thought this is due to the cold (when it happend in the winter), but evidently its not.

could it be a faulty abs. i never had the light on except for today, once.

just go reitterate car stops ok if you apply the pressure slowly. but if you want to brake HARD then its horrible. its like it reaches a threashold of stoppage and then grinds...

i dont think its my tires skidding since i know what that would sound like.

-am i not supposed to slam on brakes? just apply pressure slowly? maybe its just me.

 

Have you ever replaced the fluid?

 

fluid, SS lines, new pads (not too new. go back n forth between stock and pagid organges, new rotors, good tires.)

problem persisted for a while now.

i had the dealer once say my old rotors were "glazed".

those are gone.

 

I would go over the proper "bedding in" procedure from the pagid web site.
Uneven pad transfer can cause rotor vibration and feels like the rotor is warped.
New pads and rotors and good bedding in and you should be set.
car should stop on a dime!!!!

 

If your tires are not warm the brakes will over power them, making them slide---->>>> making the abs come one----->>>> making the grinding you feel------>>>>> making the abs light come on.


This is the most likely possibility, your brakes are working too good. That is if it's only the grinding you feel, but if it is a vibration then it's something else (bearings maybe if vibration under braking)

 

heavychevy... yea i was thinking that... however today was 80 degrees.
granted my first few minutes was when i slammed on teh brakes and had the issue which would be explained as "tires not warmed up)

however later on, once tires were warm, (driving for half an hour)..occasional WOT, heavy braking, i feel the same sensation.
it really impedes on the stopping power.

if i apply medium pressure to brakes they stop excellent.
however if i mash the pedal all the way down i feel like i exceeded the threshold of braking and im just "trying" to stop... grinding feel.


tom, for the most part i run stock pads on the car. i only put the pagids in now (they have been bedded before). for the track in a few days.

do i need to bed them in again? they ahve been bed in a few months ago.

 

Vibration under braking is almost always due to warped rotors. Happens a lot if you do hard braking and hitting deep puddles, but can happen just about anytime they rapidly heat up and cool down.

A test you can do yourself is drive the car on an empty road up to speed and see if it still does it when you use only the emergency brake to stop it. If you dont get the vibration, the front rotors are the warped ones. If its still there, its all 4.