2002 RX AWD 160,000 miles
The brake has been pulsing during normal braking for a few thousand miles now. It was intermittent at first, now it's more regular. Feels like it's the front right wheel.
Anyone have any experience with this issue and know a fix??

 

I'm not sure what you mean. Does the car sort of shake while braking because if so your rotors are likely warped?

 

Brand new rotors and pads. No shaking while braking, just the pulsing you feel when the antilock system activates. But this happens during normal braking which is not normal.

 

At what mph does this occur?

 

I'd say below 30mph. It seems that it doesn't occur until you apply enough pressure to the pedal, so it's at low speeds.

 

I had a similar issue with my neighbors Landcruiser. (175k)
Right before he comes to a stop. He would feel the ABS kick ON only the L/F wheel.

Had me baffled since everything checked out fine.
Resistance..debris on the reluctor wheel...
No ABS warning light or any stored, pending, history codes.

So I rolled the dice and put a new L/F speed sensor. Just made sense since it only happens on that side.

Problem fix.

Not saying this is your fix but it's a high probability.

 

Have you checked your tire pressure? If one tire is significantly lower than the others, it can cause the anti-lock to interpret it as slipping due to rotational speed difference.

 

One reason I disconnected my ABS back in Mexico is I had an issue where at under 5 mph like say stopping at a stoplight I'd come to a stop and then the vehicle would lurch forward after the full stop. Drove me nuts despite cleaning senors and checking the axle and I found after disconnecting it I also did better in drag racing bracket races where I was applying the brake with just the right touch as opposed to the computer assisted motions of the ABS system. ABS is nice when it works right, but when it screws up it's a royal PITA.

 

You are not alone; I too have the exact same issue. Sadly my sordid tale below does not possess a solution. :-(

For those who may not understand what's going on, the ABS system is kicking in and pushes back on the brake pedal while your braking. But this is just for normal braking: dry ground, no emergency situation, basic stop, etc. Furthermore it's intermittent: various speeds, turning or not, etc.

https://www.clublexus.com/forums/rx-...-grinding.html

That was my original post when I didn't understand the problem. I'm fairly certain now it's the ABS system that's creating the "chatter." Cleaning the front sensors didn't help and in the process broke a bolt which wasn't fun. :-(

With the weather warming I may try to clean the rear sensors, but I'm a little gun shy about breaking another bolt and I've only read one case in which cleaning the sensors solved the problem (GS400).

https://www.clublexus.com/forums/sus...no-reason.html

I will point out, for me, over time the problem has become more common. Initially it rarely happened, now it happens at least once a day. In some cases I can hear the ABS motor "spin up" (kindof like a whine) as if it's getting ready to engage and then engage (or not.) And this occurs when I'm just going leisurely down to my neighborhood stop sign <15mph.

Because of the slow progression of this problem, I think it may be the tires. Truthfully my tires are pretty well shot and I'm getting them replaced this week (Geolanders H/T.) I'm hopeful the issue goes away, but if not, I may bite the bullet and take it to the dealer. The pads/rotors are all new and I'll have new tires.

Here's a list of possible issues (please add others):

* broken tone ring aka reluctor ring (http://www.reluctorrings.com/lexus.php)
* bad or dirty ABS sensor
* bad ABS module
* worn tires?

Here's a list of threads dealing with this problem. I searched "ABS Pulsating".

https://www.clublexus.com/forums/rx-...rx300-awd.html
https://www.clublexus.com/forums/rx-...ake-pedal.html
https://www.clublexus.com/forums/rx-...s-problem.html
https://www.clublexus.com/forums/rx-...000-miles.html

In the last thread, the author had this problem *twice* and got it fixed. I PM'ed him last week to find out what the problem was and haven't heard back.

I'll keep you posted.
2000 RX300 AWD 108k

 

I hate to say this, but who sees more RX300s than anyone else - the dealer. Have any of you taken your cars to a Lexus dealer for diagnosis. Some problems are pretty rare and most independents/DIYers just never see them. If you've taken it to the dealer and drawn a blank, then fair enough. But I wouldn't want to mess with braking problems for any length of time, especially if they appear to be getting worse with time.

 

Since you live in the northeast and have high miles, take
a look at this brake problem:
http://rx300how2.home.comcast.net/~rx300how2/brakes.htm
Scroll down to "Took me a while to realize what was going on here!"
and check out the rotors that rusted and cracked in half!
Not saying this is your problem but something to look at.

 

The car has brand new rotors and pads so that rules out the worn rotor theory.
My tires are practically new, so that rules out the worn tire theory (I personally can't wrap my brain around worn tires setting off the ABS system; just doesn't make sense to me).
The suggestion that makes the most sense is replacing the speed sensor.
Thats my first course of action.....

 

Dealer says it's a bad driver's side rear axle. Not just the CV joint which has the reluctor ring on it.

Repair is ~$1500! ($950 part + labor) Yikes!

Any thoughts on whether I should look elsewhere for repair?

Researching now... would appreciate any input.

Update #1:
Rear axle shaft is all one piece with reluctor ring on it.
The reluctor ring is broken and spins freely so that's the problem.
Rear axle part #42340-48011 (interchangeable L or R)
Lexus cost ~$950.
Checked with local parts store and they said ~$70 for rear axle (manufacturer GSP)
But may not have reluctor ring as Lexus Tech points out here:
http://answers.yahoo.com/question/in...3132831AAjxPqb

Tech said they loosen axle and push it "in" to reveal reluctor ring. Otherwise (I guess) you'd have to remove hub to see ring.
Live and learn. I'll keep you posted.

 

did you have this constantly, every time when you press brake?
or only time to time?

thank you

 

I wouldn't hold my breathe to hear back from the OP. That was 3.5 years ago when he said he'd keep us posted...