took my NBP to get a fill on gas, figured since weather today was fairly warm i also took my NBP for a few fast runs (over 120mph). coming back (over 120mph) i got on the exit ramp and applied brakes. i braked probably over 1500 feet, and during last 200-300 feet i noticed brake pulse in the pedal. i suspect the rotors got hot, but brake pulse should not happen.

anyone have brake tests on the Brembo setup??

 

Could it have been the ABS? Were you pushing hard on the pedal to slow down faster?

I don't think the brakes would get that hot on only one application. Usually takes quite a few applications over a long period of time, like going down a steep hill, to even think of heating up the brakes.

 

Yup, that is ABS working.

I know cuz I hit +140 all the time and when I press the brake it does that too.

 

To quote the manual: "You will feel a pulsation in the brake pedal when the ABS activates, and may hear some noise. This is normal: it is the ABS rapidly pumping the brakes. On dry pavement, you will need to press on the brake pedal very hard before the ABS activates." (197).

I think that last part describes your situation.

 

i guess i left out some details. i was not pressing very hard. i would clasify it a medium brake. 120 down to zero at more than 1500 feet is not a heavy brake.

 

jhan1102 you take the TL upto and over 140mph and then hit the brakes so hard the ABS activates?

 

It sounds like the brakes may be programmed to activate the ABS at less pedal pressure at high speeds than low speeds, to prevent the chance of a lockup at high speeds which might not be a good thing, depending on road conditions, etc.

 

Nawwww.... Not on the TL. I did that with mod Accord V6.

But in high speed, ABS kicks in with little tab on the brake. You will feel and hear noise. Burrrrrrr. =)

If you have problems with your brake, you will see the warning lights.

 

i thought ABS cycles fast enough that you cannot feel them pulse unless the wheel starts to slip? my 4runner ABS will make a "crunching" sound if wheels start to slip.

 

no, for some reason you will hear and feel it harder. It feels like going over some new freeways road. where the grain goes side ways. Burrrrrrrrrrr... =)

 

The "feel" between warped rotors and ABS activation is quite distinguishable to me. Given your description and the 5AT TL's rotors (including mine), it takes very little to warp them. Braking from 120 mph you wouldn't feel minor warped rotors until the speed decreased to near 60. My guess if you went out and stopped firmly from 50 or so you would feel the same. I would raise the warped rotor issue flag, not ABS. Unless your braking hard enough to cause one or more wheels from rotating as fast as the others, ABS would not engage (in more or less straight line breaking). I haven't "utilized" my ABS yet, but normally a significant amount of brake/ABS "growl" is also heard.

Smitty

 

No, but it's long enough in duration to overheat & warp a brake rotor. I doubt highly that it was the ABS, but I've never driven a Honda product at that high a speed. I can say I've driven lots of TL's and CL's at highway speed that showed no brake pulsation until braking at 80 mph or more.


Sounds to me like you've warped a rotor.

 

Sounds like warped rotors. Drive it for a couple of weeks before taking maintenance action. Sometimes the warp will relieve itself and the rotor will flatten out again.

 

Check the wheel nut pressures.

 

Nothing worse than too much nut pressure