Car starts to shake when I Brake. Is it the front or rear that causes the shaking?

 

Usually it will be the rear that transmits vibration throughout the entire car. How do your rotors look? i.e. scored, lip on the outer surface? It is possible you have one or more warped rotors as well, are you a constant hard braker? Possibly a partially stuck caliper caused the warpage? You can measure the temperature of each rotor after a drive to compare and see if one or more are a lot higher than the others. Just a few thoughts, best of luck.

Warped front rotors usually start a shimmy in the steering wheel although if bad enough could very well transmit throughout the car. Nothing's impossible when it comes to cars. lol

 

The odds are you have warped rotors in the front. Try to get them resurfaced.

The biggest cause of warped rotors on Hondas and Acuras is overtightened lug nuts. That's what happens when the air gun is allowed to spin them on until IT thinks they're tight. They're supposed to be only tightened to 80ft-lbs. Responsible garages use a torque stick which stops the air gun dead when the tightness reaches a specific # of ft-lbs.
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An easy way to determine if it is the back rotors that are warped is to drive down the road and carefully apply the hand brake. This will apply the rear brakes only. If the car vibrates while doing this then you know it is the rear rotors that are warped and not the fronts. BUT, it is more common for the front rotors to warp as they are the ones that do most of the work when stopping the vehicle.

 

+1 on guessing about warped rotors, in which case it is most probably the front.

Does it do it when braking at high speeds only or also low speeds too?

My guess is warped rotor. Also you might want to try lifting the front two wheels off the ground (same time or one at a time) and spin them and listen for any rubbing. If you hear rubbing or it isn't spinning smoothly it could be something with that wheel/rotor.

 

Good info, thanks for all the feed back. Saves money to know which rotors are bad so I don't have to machine both front and rear.

If i get the rotors machined? Should I replace the pads if they are still good? Or is the pad still good from being used on warped rotors?

 

I believe the TL uses the inside of the rear rotor as a drum with seperate pads for our hand brakes. So applying the hand brake doesn't use the same rear pads and rotor surface as the regular brakes.

 

To my knowledge, if it's vibrates during braking it's always the rotor
and if it squeaks during braking then it's the pads, and all rotors can be re-serviced only once if never done before. but correct me if i am wrong....

 

You may be correct, I'm not sure. In that case, my method is useless.

 

The rotors have a minimum thickness spec. I'm not sure what the actual minimum thickness for the TL is but you can call an auto parts store such as NAPA to find out. The rotor can be turned any number of times as long as the minimum thickness requirement is still being met. All depends on how much run-out the rotors had before turning them. I think they recommend turning them when they reach .005" of run-out.

 

Can I use the same brake pads when I resurface the rotors? If the brake pads are still good.

 

^^ i don't see why not

 

Sure can. But, before reinstalling them, I like to take them outside and rub the pad on the concrete a bit. It will help knock the hard glaze off of the pad which will help reduce brake noise. Use the ol' "wax on, wax off" trick from karate kid with the pads on the concrete. Doesn't take much.

 

Are you sure?
The parking brake uses pads on the inside hub of the rotor, so if the op pulled the ebrake it wouldn't check the surface. I don't think it has anything to do with the rear braking surface on the front and rear side of the rotors if it makes sense.

 

See post #9^^^^^ I forgot the TL did this.... My bad. Must I apologize more for my mistake?? jeez... please read all posts before you attack somebody.

 

I have the same problem. I replaced the pads with OEM and resurfaced the fronts, and bought NAPA rear rotors. I would have purchased new OEM rotors if I knew how warped mine were (rears were way beyond re-surfaceable) but I was in the middle of the brake job when I found out :why me:. I again have the same vibration when braking; this time I am gonna give Brakemotive's deal a shot....front and rear slotted and drilled rotors with ceramic pads for $145. I know this sounds ridiculously cheap but people seem to like them. For the price I am willing to take the gamble and see if the extra cooling achieved with drilled rotors solves my problem. I hope you had/will-have better luck than me!

My

 

I had the front causing a nasty vibration with the orig rotors. Replaced those with acura dealer rotors, same problem within months. My other half installed EBC rotors on the front, problem solved. I was told the material or prep was bad on the dealer rotors. When he put them on, he also sanded down something until it was clean. I don't remember what that's called.

 

another thread on vibrations

here is my diagnostic tool:

1> Vibrations when braking at high speeds: Warped rotors
2> Vibrations when driving between certain speeds: Balance issues, Bent rim, bubble in tire, axle, hub-centric rings
3> Vibrations when at a stop: Vac line, mounts