Slight Vibration After Brake Replacement

[samchuang]

Hi guys,

I recently had my brakes replaced with Lexus OEM Pads (front and rear) and front rotors and have since noticed a slight vibration through the steering and chasis on the freeway.

The car wasnt vibrating like this prior to the brake job.

Brought my car in to Lexus and they rebalanced the front wheels, but the vibration still exists. The car is not pulling to either side and is running dead straight so I've ruled out it might be an alignment issue. Also, the tires have 80% tread left on them.

They've then sent out the head technician out for a test drive with me for about 30 mins cruising up and down the freeway but still couldn't really pinpoint what might be causing this. He has also checked to see whether theres any imperfections on the tires and the rims but everything seems to be ok.

Next option suggested by Lexus is to leave the car with them for a day for them to swap out the wheels and trial and test the possibilities...

Any idea what might have caused this to happen from doing a "brake job"??? Out of ideas....

[334mm]

Warped discs?

[samchuang]

The pedal is not pulsing/vibrating user braking.

The car vibrates at cruising speed so I don't think the disks are warped. Fronts are new and rears were machined.

[Iggy]

I they checked the wheel and tyre balance and rotation and the discs are good, it could be the wheel bearings or possibly worn suspension bushings.

[samchuang]

They have checked the wheel balance but not the alignment.

Tires can't be rotated as they are staggered and directional...

Could a brake job damage wheel bearing/suspension bushing? I'm not hearing the noise that's commonly associated with faulty wheel bearings though...

[334mm]

Woah woah hold on... you put new rotors and new pads on at the same time on the fronts?

This is a well known no no as it interfere with bedding process.

sorry thats off topic, cause I don't think it causes vibrations, but more so bad braking feel and power.

[Atlantis]

I've always read that about brakes, but what happens when the car is delivered from the factory with new pads and discs?

[334mm]

They do a proper bed in process from factory.

I've had to do it for a track brake set up. But essentially it's driving with the brakes engaged for some period of till they get pretty hot (not to the point they glow or anything, or till they warp... kind of guess work)

[samchuang]

I thought warped disks only causes vibration when braking? Will it also cause steering vibration at high speed not under braking conditions?

[ISF-350]

I've twice had new pads and rotors installed at the same time on previous cars (a Ralliart Colt and a Ralliart Magna) without issue or without hearing of issues occurring??

[Atlantis]

Yeah, I've upgraded to new pads + discs at the same time twice before and haven't had this issue either. But I have read the advice not to do it at the same time as well. *Shrug*

[334mm]

sam: If you are getting this problem while driving high speed, then yes something is pretty wrong! Get it fixed immediately.

I think it may also depend on the setup. I've actually had a panic phone call from a mate once on this issue.

He got his rotors machined, and got his new track pads put in. On the way home half the trip was fine, until he had to emergency brake. FAIL lol... no "full" braking force. I told him how to bed them in, and it was fine from there on.

[samchuang]

Thanks for your inputs guys.

My brakes seem to work perfectly without squeal, brake pulse or brake failiure...

It's just that the car doesn't cruise smoothly like it did before the brake job...

[LEX51S]

Check this out.

Good read.

http://au.lexusownersclub.com/forums/index.php?showtopic=10405&hl=%20brake%20%20shudder.%20%20&st=0

[Iggy]

sorry to resurrect a dead thread, I had a similar experience of uneven/almost shuddering feel after replacing the rotors and pads. It was weird because there was none of that when braking harder only when normal pressure is applied. I took apart the whole rotors and pads and found nothing wrong but discovered that the pins were not sliding very smoothly, one side was almost ceased completely. I took them out cleaned and applied brake pin grease and what a difference it made. The braking is progressive and smooth like it was when I first bought the car.

I have changed brakes/rotors on all my cars for the past 15 years but none needed pin lubrication, so I learned a lesson here and maybe someone can learn from my mistakes and lubricate pin every time.

[Sapphire Cam]

WOOOAH!!! Had the same issue myself a year ago or so. I posted it on this forum. It came down to an overtightening of the park brake by the technician during the brake service/replacement. The symptoms were exactly that samchuang mentions here in his initial post. At speed. The hypothesis goes:

- Park brake overtightened slightly. When disengaged, the shoes of the park brake are still ever so slightly touching the barrel/drum of the park brake. If you then hit high speed within 10-15mins of being parked (I found it at 85km/h+) you could get a shudder as the park brake has heated up and is starting to give a warped feel (ie. shudder). It eventually goes away, as the park brake loosens over time. OR go to your dealership and get it slackened slightly.

For this shudder my Lexus dealership/technician checked: pads, calipers, rotors, transmission, driveshaft, suspension, did two road tests, checked ECU/readouts. I also had my tyres re-balanced and aligned at a third-party tyre centre. I also did some braking tests at various speeds. It eventually was determined it was an overtightened park brake.

[PRV]

Hi Sapphire Cam, I too have had this. Except it felt like the car was being shaken from side to side at speed. Lexus fixed it quickly when they saw the park brake pads(?) were scortched just on the driver's side.

[phantom007]

Hi, I just replaced my rotors because of a vibration in the pedal when braking. An interesting instruction sheet accompanying the rotors says

"Failure to properly clean the hub surface will result in disc rotor run out. ......The result of run out is DTV ( Disc Thickness variation ) which can occur in only a thousand kilometres resulting in pedal pulsation, vibration or knocking "

And " When refitting wheel nuts, torque as per vehicle manufacture instructions. DO NOT use an impact gun as over tightening can distort the hub and rotor causing disc run out."

I tighten the two screws that hold the rotor to the hub with a impact driver and spun the disc and it acted like it was buckled, I loosened them and retightened by hand and it ran strait.