Brake Pulse/vibration, What Can It Be?

[rlin78]

My Rx300 has this weird pulse/vibration that I can't pinpoint. At first I thought it was the ABS because it feels like ABS motor pulsing the brakes, then since it happened more and more often and even at very slow (2-3 MPH), I know it is not the ABS. it feels like something is scratching the rotor a few times a second. So I thought it just be something uneven on the surface of the rotors that's scratching the brakes.

I replaced the brake pads and rotors thinking the problem would go away, but instead, it is still there. Sometimes I get very smooth braking, sometimes I get the pulse, does anyone know why and most importantly, how to fix the problem.

[Booyah]

I wish I new, because Im having the same thing as you on my 99 4Runner. Replaced pads and resurfaced rotors by toyota and I still get vibration when I brake--just like warped rotors would do....I dont have any of the scratching noise though

Im going to take it back and let them look at it?

[TunedRX300]

Check calipers, it is early for rebuilt but make sure those pistons won't be stuck.

[rlin78]

Check calipers,  it is early for rebuilt but make sure those pistons won't be stuck.

←

Not quite sure where you are going with this. I was able to push the pistons back, so it's not stuck, right? <_< They were easy to push back too....

[SKperformance]

If the person who does your brake changes does not lube the sliders and pistons they can seize.

The main slider bolts need lube to let the caliper float back and forth on the rotors.

[TunedRX300]

SKPerformance is right, check the glider pin also. See quote from

https://www.burtonpower.com/technical/tt_brakes.html

"Brake Juddering

Brake juddering is a fairly common complaint on all cars, whether standard or high performance. In most cases, the brake discs will have warped and a replacement set is the obvious cure for the problem. However, the cause of the problem can often be found elsewhere and the replacement discs will soon warp as well. It is not only essential to fit new brake discs, but to also rectify the cause of the problem in the first place, otherwise the juddering is likely to return.

From our own experience, we have found that the following causes are likely to result in a warped brake disc:

Seized calipers - either a seized caliper piston or a seized caliper sliding pin will result in uneven forces being applied to each side of the brake disc. Suspension bushes - tired TCA or anti-roll bar bushes.

Poor quality pads - these can overheat quickly, particularly if the brakes are used often and hard. The excessive heat from the pads can cause the discs to overheat, resulting in the discs warping.

Hubs - although rare, it is possible for the hubs to warp. Bolting a disc to a warped hub will always result in brake vibration. The same will also happen if any rust from the hub face is not removed before fitting the disc. After fitting a disc, we always recommend checking for disc run-out using a dial gauge. If the run-out is out of tolerance, then the disc should be re-fitted in an alternative position (i.e. turned through 90o) until run-out is within tolerance."

[rlin78]

If the person who does your brake changes does not lube the sliders and pistons they can seize.

The main slider bolts need lube to let the caliper float back and forth on the rotors.

←

What do you use to lube the bolts? Anti-seize?

[TunedRX300]

Grease

[lenore]

Molylube black lithium

[rlin78]

People, I am running out of ideas. I replaced the rotors, brake pads, even the calipers, and lube the sliding bolts. I am still getting the vibration :chairshot: , kind of feels like ABS kicking in, but I don't hear the ABS pump going off. And I've also checked the wheel bearing by shaking the wheel with the tire off the ground, all 4 tires are tight. Has anyone seen anything like it? By the way, sometimes it is very smooth, but sometimes I feel the vibration, very weird :(

[mikey00]

People, I am running out of ideas.  I replaced the rotors, brake pads, even the calipers, and lube the sliding bolts. I am still getting the vibration :chairshot: , kind of feels like ABS kicking in, but I don't hear the ABS pump going off.  And I've also checked the wheel bearing by shaking the wheel with the tire off the ground, all 4 tires are tight.  Has anyone seen anything like it?  By the way, sometimes it is very smooth, but sometimes I feel the vibration, very weird :(

←

You may want to pull the ABS fuse and do a test run. If nothing else, this will at least eliminate the ABS as a possible cause.

[rlin78]

People, I am running out of ideas.  I replaced the rotors, brake pads, even the calipers, and lube the sliding bolts. I am still getting the vibration :chairshot: , kind of feels like ABS kicking in, but I don't hear the ABS pump going off.  And I've also checked the wheel bearing by shaking the wheel with the tire off the ground, all 4 tires are tight.  Has anyone seen anything like it?  By the way, sometimes it is very smooth, but sometimes I feel the vibration, very weird :(

←

You may want to pull the ABS fuse and do a test run. If nothing else, this will at least eliminate the ABS as a possible cause.

←

Easier said than done. Has anyone tried to pull the ABS fuse? I tried and can't get it off, I even tried a pair of plier. thanks Lexus. :chairshot:

[mikey00]

People, I am running out of ideas.  I replaced the rotors, brake pads, even the calipers, and lube the sliding bolts. I am still getting the vibration :chairshot: , kind of feels like ABS kicking in, but I don't hear the ABS pump going off.  And I've also checked the wheel bearing by shaking the wheel with the tire off the ground, all 4 tires are tight.  Has anyone seen anything like it?  By the way, sometimes it is very smooth, but sometimes I feel the vibration, very weird :(

←

You may want to pull the ABS fuse and do a test run. If nothing else, this will at least eliminate the ABS as a possible cause.

←

Easier said than done. Has anyone tried to pull the ABS fuse? I tried and can't get it off, I even tried a pair of plier. thanks Lexus.:chairshot:

←

There should be 2 ABS circuit breakers in the engine compartment fuse box. I know others had the ABS sensor ring fail, which is part of the axle, and pulled the circuit breakers rather than have the whole axle replaced. Of course, now they don't have ABS, but it is better than it activating all the time. I am not sure if there is a trick to pulling the breakers and I can't check right now because the wife is out with the car.

[rlin78]

People, I am running out of ideas.  I replaced the rotors, brake pads, even the calipers, and lube the sliding bolts. I am still getting the vibration :chairshot: , kind of feels like ABS kicking in, but I don't hear the ABS pump going off.  And I've also checked the wheel bearing by shaking the wheel with the tire off the ground, all 4 tires are tight.  Has anyone seen anything like it?  By the way, sometimes it is very smooth, but sometimes I feel the vibration, very weird :(

←

You may want to pull the ABS fuse and do a test run. If nothing else, this will at least eliminate the ABS as a possible cause.

←

Easier said than done. Has anyone tried to pull the ABS fuse? I tried and can't get it off, I even tried a pair of plier. thanks Lexus.:chairshot:

←

There should be 2 ABS circuit breakers in the engine compartment fuse box. I know others had the ABS sensor ring fail, which is part of the axle, and pulled the circuit breakers rather than have the whole axle replaced. Of course, now they don't have ABS, but it is better than it activating all the time. I am not sure if there is a trick to pulling the breakers and I can't check right now because the wife is out with the car.

I just want to update everyone. Finally, after exhausting other possibilities, I pulled one of the ABS relays because I couldn't get the fuse off. It is amazing how much faster the car stops now, however, the ABS light in the dash is on. So after $300 and countless hours taking the brakes apart / putting them back to together, I replaced 4 rotors, 4 brake pads, and 2 front calipers just to find out it is the ABS system that's giving the problem. Good thing is that I worked on the car myself, but I think everyone should try the easiest thing to do first when troubleshooting.

Now does anyone have any ideas which part of the ABS is at fault? Is it really the sensor ring? I had more faint in Lexus before owning one, now it has turned out to be less reliable than my Nissan Maxima with more miles. After 1 year of ownership, I have had to replace the alternator and now ABS parts. The transmission is holding up so far, fingers cross.

Edited January 20, 2006 by rlin78

[chimchim]

Now does anyone have any ideas which part of the ABS is at fault? Is it really the sensor ring? I had more faint in Lexus before owning one, now it has turned out to be less reliable than my Nissan Maxima with more miles. After 1 year of ownership, I have had to replace the alternator and now ABS parts. The transmission is holding up so far, fingers cross.

See if gunk is blocking the "sight" of the ABS speed sensor. Also, see if the sensor somehow got knocked too far away from the hub. (I don't know spec, but if the other wheel is ok, compare the distances)

[llbouch]

People, I am running out of ideas.  I replaced the rotors, brake pads, even the calipers, and lube the sliding bolts. I am still getting the vibration :chairshot: , kind of feels like ABS kicking in, but I don't hear the ABS pump going off.  And I've also checked the wheel bearing by shaking the wheel with the tire off the ground, all 4 tires are tight.  Has anyone seen anything like it?  By the way, sometimes it is very smooth, but sometimes I feel the vibration, very weird :(

←

You may want to pull the ABS fuse and do a test run. If nothing else, this will at least eliminate the ABS as a possible cause.

←

Easier said than done. Has anyone tried to pull the ABS fuse? I tried and can't get it off, I even tried a pair of plier. thanks Lexus.:chairshot:

←

There should be 2 ABS circuit breakers in the engine compartment fuse box. I know others had the ABS sensor ring fail, which is part of the axle, and pulled the circuit breakers rather than have the whole axle replaced. Of course, now they don't have ABS, but it is better than it activating all the time. I am not sure if there is a trick to pulling the breakers and I can't check right now because the wife is out with the car.

I just want to update everyone. Finally, after exhausting other possibilities, I pulled one of the ABS relays because I couldn't get the fuse off. It is amazing how much faster the car stops now, however, the ABS light in the dash is on. So after $300 and countless hours taking the brakes apart / putting them back to together, I replaced 4 rotors, 4 brake pads, and 2 front calipers just to find out it is the ABS system that's giving the problem. Good thing is that I worked on the car myself, but I think everyone should try the easiest thing to do first when troubleshooting.

Now does anyone have any ideas which part of the ABS is at fault? Is it really the sensor ring? I had more faint in Lexus before owning one, now it has turned out to be less reliable than my Nissan Maxima with more miles. After 1 year of ownership, I have had to replace the alternator and now ABS parts. The transmission is holding up so far, fingers cross.

Hey rlin78

I've just read your post about your brake problem. I just bought a 2000 Rx 300 with 63,000 miles and I am having the exact same problem that you had.

I would like to know if you had the problem fixed and what part of the ABS was at fault and a ball park figure of the cost.

Thanks

llbouch

[rlin78]

llbouch,

Good luck with your brake problem. I ended up taking it to the dealership, they used their diagnostic machine, told me there's nothing wrong. Then I took it in for the second time, they said it was the rear sensors, cost over $600. I ok the repair, they called me a couple days later, told me it was the sensor ring which was the whole axle. Final bill was around $1500.

I called Lexus and told them it was a design flaw, but they said since the vehicle came from the north, it was rusted by salt, that's why it failed. I don't think something that was supposed to save you should fail like that and cost so much to repair. You might be better off pulling the fuse. I know I am probably not going to buy a used Lexus again.

[llbouch]

llbouch,

Good luck with your brake problem. I ended up taking it to the dealership, they used their diagnostic machine, told me there's nothing wrong. Then I took it in for the second time, they said it was the rear sensors, cost over $600. I ok the repair, they called me a couple days later, told me it was the sensor ring which was the whole axle. Final bill was around $1500.

I called Lexus and told them it was a design flaw, but they said since the vehicle came from the north, it was rusted by salt, that's why it failed. I don't think something that was supposed to save you should fail like that and cost so much to repair. You might be better off pulling the fuse. I know I am probably not going to buy a used Lexus again.

Thanks for the quick reply. I don't think I'll be bringing my vehicle to the dealer as they are way over priced just for the lexus name. Again thanks

[allen2030]

llbouch,

Good luck with your brake problem. I ended up taking it to the dealership, they used their diagnostic machine, told me there's nothing wrong. Then I took it in for the second time, they said it was the rear sensors, cost over $600. I ok the repair, they called me a couple days later, told me it was the sensor ring which was the whole axle. Final bill was around $1500.

I called Lexus and told them it was a design flaw, but they said since the vehicle came from the north, it was rusted by salt, that's why it failed. I don't think something that was supposed to save you should fail like that and cost so much to repair. You might be better off pulling the fuse. I know I am probably not going to buy a used Lexus again.

My 2002 RX 300 is in Austin, TX and it has been viberating! since I bought it used about a yr. ago.... I know nothing is wrong with the brakes. I balanced the wheels. It reduced the vibes but it still does it. I am just going to live with it and consider it a design flaw. As long as the car stops, a little vibe is good....

My next car will be Prius!

[lenore]

You know I just read all of this, I wonder if cleaning each of the ABS sensors at all wheels and cleaning the sensor rings with a brass brush to clean any buildup would fix the problem. I just replaced the left front axle shaft and when I removed the sensor it had some light metal debris stuck to it. I cleaned it and didnt think much about it, but maybe all of the wheels have some debris on the sensors. After all mine is an 8 years old car. May be worth a little time and effort and may solve these vibration problems. Lexus folks are parts changers, example MAF sensor when just some cleaning will fix problems. Hope you all read this and if you try it give some feedback if it solves the vibration.....

[SexyLexy430NY]

the vibration im getting from the rear...seems to have something to do with the bearings...NOTTT!!!

thats what i thought! replaced the bearings..cost me a lot..

but it didnt solve it!!

Im pretty sure I need new control arms in the back and that will get rid of the vibration, but its not major!

The vibration.shaking i got in my steeering turned out A LOTTT of posts..

This was the result:

I still have vibration after tire rotation and alignment.

I am going to get ROAD FORCE Balancing from a Hunter balancing maching.

This should solve the problem!! I heard it is very PINPOINT and exact!

if it doesnt, I am gonna make sure my rims arent warped and my tires are all round. If that doesnt solve it...I give upp :-\

it may also be sticking calipers which is doubtful, or i heard going abck and amking sure I have factory lugnuts will also solve the problem.

And after searching about my tires, I realized they are not bad and they match my facotry specifications!

Hope i helped someone who is having the same problems as me!!

[sorryd]

My Rx300 has this weird pulse/vibration that I can't pinpoint. At first I thought it was the ABS because it feels like ABS motor pulsing the brakes, then since it happened more and more often and even at very slow (2-3 MPH), I know it is not the ABS. it feels like something is scratching the rotor a few times a second. So I thought it just be something uneven on the surface of the rotors that's scratching the brakes.

I replaced the brake pads and rotors thinking the problem would go away, but instead, it is still there. Sometimes I get very smooth braking, sometimes I get the pulse, does anyone know why and most importantly, how to fix the problem.

i own a 2000 gs 400 and the same thing was happenning to me but i went back removed the abs sensor cleaned it and checked the inside (abs rotor back) to make sure it wasnt missing any teeth.after i made sure that the abs sensor it self fitted all the way in made it real tight but (careful screw can break) and this fixed the problem oh abs sensor does not use any type of washer in between