Brakes vibrate under hard braking

[Lifer]

Brakes kinda vibrate/pulsate under hard acceleration (braking).
less noticeable to non-existent during like braking.

brake pads were changed 15k miles ago.

warped rotors?

edit: whoops, i meant the hard breaking kind of acceleration.

 

[Kaervak]

Originally posted by: Lifer
warped rotors?

That would be my guess.

 

[Electric Amish]

Brake vibrate during "Acceleration"???

If it's during deceleration then it's either warped rotors or the anti-lock pulsing.

 

[kehi]

definately warped rotors if felt under hard braking, time for them to be "shaved"/"turned"

 

[MichaelD]

Originally posted by: Kaervak

Originally posted by: Lifer
warped rotors?

That would be my guess.

Me too. Just to be sure, remove the front wheels, spray the rotors/calipers with a hose; you might have so much brake dust built up that it's causing vibration. That's possbile, but it's most probably the rotors.

The hose thing is a FREE fix..if it works.
good luck.

 

[Kntx]

Brake vibrate during "Acceleration"???

in a strict sense braking is considered acceleration

 

[Atrail]

r o t o r s

more than likely

 

[notfred]

Warped rotors don't make the brakes vibrate, they make the steering wheel vibrate. If you're feeling the brakes pulsating, that's what ABS is.

 

[MichaelD]

Originally posted by: notfred
Warped rotors don't make the brakes vibrate, they make the steering wheel vibrate. If you're feeling the brakes pulsating, that's what ABS is.

I disagree. If the rotors are warped, the pulsing will be felt at the brake pedal:

1. Rotor pulses due to warpage
2. Pulsing transmitted, via brake fluid, thru brake lines
3. Pulsing felt back at head-end, i.e. the brake pedal.

And yes; I know exactly how an automotive braking system works. When you press the pedal, it pushes a rod forward, moving a piston inside the master cylinder. That moving piston compresses the fluid, activiating calipers/shoes.

You WILL feel pulsing at the pedal if your rotors are warped.

 

[WinkOsmosis]

I feel my pedal vibrate if I lock my brakes .

 

[Graphicd00d]

Originally posted by: notfred
Warped rotors don't make the brakes vibrate, they make the steering wheel vibrate. If you're feeling the brakes pulsating, that's what ABS is.

I was about to say this. If you have ABS and slam on the brakes and you feel a vibration it's the ABS working.

 

[Lifer]

no ABS.

not sure where the vibration is felt... the steering wheel kinda shakes too I guess
but i can definitely feel the brake pedal.

 

[Jugernot]

Originally posted by: Lifer
Brakes kinda vibrate/pulsate under hard acceleration (braking).
less noticeable to non-existent during like braking.

brake pads were changed 15k miles ago.

warped rotors?

edit: whoops, i meant the hard breaking kind of acceleration.

Yep, warped rotors... sorry dude.

 

[notfred]

Originally posted by: MichaelD

Originally posted by: notfred
Warped rotors don't make the brakes vibrate, they make the steering wheel vibrate. If you're feeling the brakes pulsating, that's what ABS is.

I disagree. If the rotors are warped, the pulsing will be felt at the brake pedal:

1. Rotor pulses due to warpage
2. Pulsing transmitted, via brake fluid, thru brake lines
3. Pulsing felt back at head-end, i.e. the brake pedal.

And yes; I know exactly how an automotive braking system works. When you press the pedal, it pushes a rod forward, moving a piston inside the master cylinder. That moving piston compresses the fluid, activiating calipers/shoes.

You WILL feel pulsing at the pedal if your rotors are warped.

Maybe if you have manual brakes, which very few cars have now. I really doubt you would (and in my experience, never have) feel the pedal pulsate due to warped rotors on a car with power brakes.

 

[Bleep]

A lot of newer cars have such thin rotors that when they heat up they will warp and then return to almost straight after cooling. I would recommend that you have your rotors checked for runout, if you can weasel out a dial indicator from someone you can do this yourself. Do a search on Google there is more than likely a site that will tell you how to do this.

Bleep

 

[Lifer]

how much does getting rotors replaced/sanded(?) cost?

any danger with running them as is for the time being?

 

[The Stigenator]

Originally posted by: Lifer
Brakes kinda vibrate/pulsate under hard acceleration (braking). less noticeable to non-existent during like braking. brake pads were changed 15k miles ago. warped rotors? edit: whoops, i meant the hard breaking kind of acceleration.

I didnt read the rest of teh thread but Your Car has ABS

 

[Lifer]

Originally posted by: The_good_guy

Originally posted by: Lifer
Brakes kinda vibrate/pulsate under hard acceleration (braking). less noticeable to non-existent during like braking. brake pads were changed 15k miles ago. warped rotors? edit: whoops, i meant the hard breaking kind of acceleration.

I didnt read the rest of teh thread but <STRONG>Your Car has ABS</STRONG>

how are you going to tell me what options my car have. you don't even know that when my car was built, ABS was not even invented yet.

so NO, it does not have ABS

 

[ScrapSilicon]

Originally posted by: Lifer

Originally posted by: The_good_guy

Originally posted by: Lifer
Brakes kinda vibrate/pulsate under hard acceleration (braking). less noticeable to non-existent during like braking. brake pads were changed 15k miles ago. warped rotors? edit: whoops, i meant the hard breaking kind of acceleration.

I didnt read the rest of teh thread but <STRONG>Your Car has ABS</STRONG>

how are you going to tell me what options my car have. you don't even know that when my car was built, ABS was not even invented yet.

so NO, it does not have ABS

interesting...what is your vehicle...?

 

[C'DaleRider]

Originally posted by: notfred

Originally posted by: MichaelD

Originally posted by: notfred
Warped rotors don't make the brakes vibrate, they make the steering wheel vibrate. If you're feeling the brakes pulsating, that's what ABS is.

I disagree. If the rotors are warped, the pulsing will be felt at the brake pedal:

1. Rotor pulses due to warpage
2. Pulsing transmitted, via brake fluid, thru brake lines
3. Pulsing felt back at head-end, i.e. the brake pedal.

And yes; I know exactly how an automotive braking system works. When you press the pedal, it pushes a rod forward, moving a piston inside the master cylinder. That moving piston compresses the fluid, activiating calipers/shoes.

You WILL feel pulsing at the pedal if your rotors are warped.

Maybe if you have manual brakes, which very few cars have now. I really doubt you would (and in my experience, never have) feel the pedal pulsate due to warped rotors on a car with power brakes.

Guess you aren't very experienced then. Feeling warped rotors is quite common, especially warped rotors on FWD cars. The rotors on FWD cars are very light as compared to a typical RWD car. Warping the rotors is a common occurance after having tires removed and replaced and the mechanic used an impact gun, especially on FWD cars with alloy wheels. It is rare that impact guns torque each lug nut to the dame torque....the air pressure drops off or the compressor kicks in part way through the job and gives an uneven torque across the wheel. After some time, the heating/cooling of the rotor, faced with the wheel's lugs being at very different torques, warps the rotors. You can feel the pulsing through the brake pedal and if bad enough, through the seat of your pants.

In an effort to get better milage, the rotor thickness is constantly being reduced and likelyhood of warping is increased, as is the likelyhood as the rotor wears out. Thank goodness on FWD, at least, the rotors are easy to change and fairly cheap.

Warpage can easily happen on RWD vehicles, too. Dealer just had to replace the rear disc rotors on our Blazer due to .....WARPAGE of the rotors that we could feel through the pedal and vehicle when braking.