shikbas

Hi very helpful guys
I have 04 rx330 with 70 k miles. Lately I started to feel grinding sensation and pulsation on applying the brakes initially it is fine then it will be felt specially when the car comes to near stop
A mechanic looked at it and said bad rotor I relaced with new rotors and pads still doing the same thing, as I inspected the old rotors and pads there was no visible deffects.
Appreciating your help

fastnoypi

how many miles did it take to feel the brake pulsation after rotor replacement? Did you do a brake pad bed in procedure?

shikbas

Thank you
I just replaced the rotors today and it started to happen at the pad bedding procedure so that it was few hundreds feet

aarghj

I have this same problem. For me, 160k miles, it is a slight but noticeable hop or shudder (only when cold) when I first start to move, at low speeds. Once the car warms up, it is only noticeable when braking, but the harder I brake, the more severe and pronounced it gets. It also gets more pronounced or noticeable as the car decelerates. I have zero idea what could be causing it. it has gotten worse over the last 30k miles.

Edit to say, I can feel this shudder in both the steering wheel and in the seat. My wife noticed it this morning from the passenger seat as we went to the store. I'm afraid to drive it around much any more.

fastnoypi

In that case there is no way the pads got hot enough to bed the rotors to transfer material.

Id try first by unmounting both the front wheels and rotors and really ensuring the hub surfaces are clean. Secure the wheels while on stands in the 5 lug star pattern, and re-torque to spec on the ground.

Another thing to look at are the brake caliper pistons. If someone can depress the brake pedal halfway while you look at the pistons when off the rotor, they should both move close to the same rate.
Do not press the brake pedal all the way or the pistons may completely come out.
If they don't move at the same rate, a caliper rebuild might help. It requires a new "square" seal and dust boot for each piston.


@aarghj you probably have a case of max rotor runout or you are below minimum thickness. A good tech or machine shop should be able to measure it. If you still have enough rotor left, a machine shop could turn the rotors to get a few more hundred miles out of them.

shikbas

Thank you all. A friend mentioned the possibility of deffective ABS sensors. What do you think?
Thanks in advance

fastnoypi

very possible, but i haven't come across the grinding problem when one of my sensor went bad and i had some codes.
They are easy enough to clean and replace with minimal tools.

Check this thread out if you suspect it is ABS https://www.clublexus.com/forums/rx-...-solid-on.html

shikbas

Thank you guys
After reading all the information I started wigh the front wheel took the abs sensor out checked the tone ring and wala it was broken completely got a new cv axle and was installed and problem solved
For you guys who may have the same issue a press shop told me that they can press a new tone ting on the axle for me it was too late as a new one was already installed