Another Brake Issue

[Strum]

Today I drove about 10 miles before getting on the freeway. After driving a mile on the freeway I had to lightly hit the brakes and the steering wheel started shaking. This happen a few more times before it stopped shaking.

I stopped for about 45 minutes, drove again about 10 miles before entering the freeway and the same thing happened again. I hit the brakes three or four times and the problem stopped.

The car shows no problems with stop and go traffic, only happens on the freeway and only for a short period.

[masonm]

Rotors are probably warped. If you know how to check and diagnose, it's an easy fix. If not, take it to your mechanic and have him/her check it out.

[95WhiteCamry]

could be a wheel balancing issue. resonance frequency usually starts around highway speeds, so that would make sense that you don't feel it during street traffic. since you hit the brakes a few times on the freeway , you might've went under the resonance frequency so that the vibrations are not as pronounced. it's kind of a long shot, but it's something to look out for as well.

with warped rotors, i have a feeling that you would feel vibrations at any speed.

[Strum]

Originally Posted by 95WhiteCamry

could be a wheel balancing issue. resonance frequency usually starts around highway speeds, so that would make sense that you don't feel it during street traffic. since you hit the brakes a few times on the freeway , you might've went under the resonance frequency so that the vibrations are not as pronounced. it's kind of a long shot, but it's something to look out for as well.

with warped rotors, i have a feeling that you would feel vibrations at any speed.

I thought about both the balance and the warped rotors. The odd thing about when I braked a few times, I could go back up to that speed or faster and then brake again with no problem. I expected it to be more pronounced when I came off the ramp, but there was no wheel shake or pulsating effect. Just seems odd.

As for fixing a warped rotor, aren't the only two options turning or replacement?

[SexieWASD]

Originally Posted by Strum

I thought about both the balance and the warped rotors. The odd thing about when I braked a few times, I could go back up to that speed or faster and then brake again with no problem. I expected it to be more pronounced when I came off the ramp, but there was no wheel shake or pulsating effect. Just seems odd.

As for fixing a warped rotor, aren't the only two options turning or replacement?

You might as well go for a replacement set, if you want to get them turned you probably have expensive rotors, but if they warped you paid too much for them and should have got slotted rotors anyway, but those can't be turned. And if they are a cheap set that warped turning won't be much cheaper than just getting a new set.

Camry's love warping rotors though, it's their favorite thing to do, You have a few options once you get a new set, you can go really easy on the new set until they get tempered from the heat. you can get rotors that stay cooler, or you can get pads that go easy on the new set for you, like Wagner edge brake pads (over priced, but they work like a charm.)

[500KCamry]

Also check to see if the caliper is moving freely on its pins and that the wheel nuts are feel equally tight. This will make sure the rotor isn't being pulled or pushed out (warped) under braking.

[Strum]

I wasn't aware of the big difference in performance in rotors. What do I get with slotted rotors and is it worth the bang for the buck?


500K, I will have to check out the brakes like you note. It certainly is a lot cheaper than dumping in money if it isn't needed.

I use to drive the car about 90 to 100 miles a day (prior to Jan 09), but now only drive it about 20 miles a day. Since I seldom get on the freeway, I never noticed an issue with the brakes before.

[SexieWASD]

Performance rotors can just handle more heat, you would probably get more bang for you buck by using the other two options (being gentle, or getting better pads if being gentle isn't your thing). but regardless of how good your pads are, or how gentle you are a stuck slider pin will mess stuff up.

[Strum]

Originally Posted by SexieWASD

...slider pin will mess stuff up.

What exactly are you referring to when you say slider pins?

[SexieWASD]

The caliper doesn't bolt solid to the bracket that holds the brake pads, it rests on smooth pins so that it squeezes the rotor instead of just pressing on one side of it. If the caliper seizes on one or both of the pins when you hit the brakes that caliper will push out on the rotor instead of squeezing tight.

[Mike Gerber]

"If the caliper seizes on one or both of the pins when you hit the brakes that caliper will push out on the rotor instead of squeezing tight."

It also will not usually allow the caliper to retract, causing constant pad to rotor brake pressure. This can overheat the rotor and cause the rotor to warp. In extreme cases the heat caused by this constant brake pressure can even cause the brake fluid to boil. In that case the pedal can go right to the floor without applying brake pressure and stopping the car.

Mike

[Strum]

Originally Posted by Mike Gerber

"If the caliper seizes on one or both of the pins when you hit the brakes that caliper will push out on the rotor instead of squeezing tight."

It also will not usually allow the caliper to retract, causing constant pad to rotor brake pressure.

Mike

I think this was the issue when I purchased the car. The caliper was causing the inner pad not to retract and it was worn down to almost metal while the outer was close to looking new.

It would be odd for a second set of calipers to do that - wouldn't it? Then again, it's a car and anything is possible.

[Default User]

Originally Posted by SexieWASD

Performance rotors can just handle more heat, .

Excessive heat can warp the rotors - Cheap rotors overheat quicker than OEM



I may be way off - but my old T4R had the same symptoms - had rear Diff fluid bleeding on to the rear brakes causing it to grab and slip intermittently.
Felt almost like ABS was kicking in.

You might want to get those brakes checked properly before you tell some tech to change the pins and rotors. (because that's all they'll do. they probably wont check anything else)

[JohnGD]

+1 here.

I think the caliper, and in particular, the anchor pins may be binding.

Don't resurface the rotors. They only warp faster. However, swap them left to right and see if the vibration goes to the other side.

And properly torque down the lug nuts in three stages.

Originally Posted by 500KCamry

Also check to see if the caliper is moving freely on its pins and that the wheel nuts are feel equally tight. This will make sure the rotor isn't being pulled or pushed out (warped) under braking.

[JohnGD]

What's your mechanical capability. Will you be able to replace all rubber parts using a caliper minor rebuild kit?

Originally Posted by Strum

Today I drove about 10 miles before getting on the freeway. After driving a mile on the freeway I had to lightly hit the brakes and the steering wheel started shaking. This happen a few more times before it stopped shaking.

I stopped for about 45 minutes, drove again about 10 miles before entering the freeway and the same thing happened again. I hit the brakes three or four times and the problem stopped.

The car shows no problems with stop and go traffic, only happens on the freeway and only for a short period.