HELP: 93 Toyota Corolla vibration problem!

I replaced the brake hoses. Problem still persists. But please notice that in my story about my trip to the airport, I did not use my brakes for like 30 miles of hte trip since there was no traffic on the highway at 3AM. But, at one point, without using my brakes at all, the problem started. It starts as you notice more gas pedal effort needed to move the car (dragging), then the vibration starts gradually and builds up in intensity. I can only assume this might be caused by the wheel getting hotter and hotter and eventually heating up the tire.... does this make sense? could it be a brake booster problem?

-Jon

Good point. But wouldn't the bad CV likely make a clicking sound during turns and cause vibration nearly always on the highway?

Well, I did replace the calipers 3k ago. Could it be that the passenger-front one is bad? They were rebuilds after all... and that is the side that is heating up...

Yes, that is certainly a possibility. If you did something to the brakes, then things started heating up, then chances are something that you did to the brakes caused the problem.

Jeff

That's going to be my next test. The mechanic will replace that caliper under warranty. Then I'll see if the problem persists. that will be Thursday.

If it's only one wheel, I'd strongly suspect the hose. Second choice would be frozen up mounting hardware causing a single piston caliper not to float freely. A booster, master cylinder, or pushrod adjustment issue would show up on at least two if not all four wheels.

nate

Hmm. disregard my last post then. Did you thoroughly clean the mounting hardware (esp. sliders) when you replaced the calipers? Assuming, of course, that these are single piston type with sliders.

Do you have any noticeable play in that wheel bearing? I can't see how that would cause the brakes to drag/rotor to overheat, but it seems like you've covered the likely culprits already.

nate

Yes

A bad bearing will not always have play in it but it should be noisy. I have never seen a bad bearing cause a vibration.

Even thought the rotor is fairly new if it was warped from the brakes being applied it needs to be machined or possibly even replaced.

You stated that it is only one front wheel that is getting hot so it would have to be the caliper, pads, brake hose or steel line going to that particular wheel.

could a bad booster cause it?

No. A bad booster would affect all wheels. When a booster fails it will generally make the brake pedal hard to depress.

Good point, but that would also imply that the self-adjusting hardware was frozen up on at least one rear wheel. Not impossible, but would imply two simultaneous problems. That said, it might not be a bad idea to check anyway, since the OP has apparently tried all the obvious stuff.

nate

No

No

How warped would a wheel have to be to cause this?

Extremely warped.

There is

Then your problem is with the brakes.

The other day i drove to

Right, the brakes drag causing the rotor to get hot and warp which causes the vibration.

You can feel that you need more gas pedal effort to

Not really, you have covered this at least a half dozen times already.

Bad point. A bad CV joint WOULD NOT cause the brakes to lock up.

Lets start from the begining. If I understand correctly you replaced the front calipers first. Why ? Were the brakes acting up before you replaced the calipers. You then replaced the brake hoses and this did not correct the problem. The right front brake is the one getting hot, correct ? Are you doing the work or are you taking it to a shop ?

Whcih was already replaced and had no affect on the problem.

Second choice

Or two problems combined. It is possible that the left front caliper is seized up AND the master cylinder pushrod misadjusted. This would put all the pressure on the right front caliper.

A booster, master cylinder, or pushrod

Both fronts should apply together so it is possible that one front brake IS NOT applying.

I don't believe Toyota uses a diagonal braking system.

I replaced the calipers because the brakes felt "soft" and i was not getting good stopping power. The replacement cured it. But shortly thereafter this problem occured. And I was not sure of the cause because i replaced the calipers and tires at about the same time. So after the vibration started, i brought it to my mechanic who found that the rotor or rotors were blued and replaced them. Obviously he cured the symptom and not the disease at this point. Then i replaced the tires under waranty because i thought they were defective. After this, i noticed taht one wheel was getting hotter than the other. I then replaced the brake hoses on both sides. This still did nothing. Now I am going to try the caliper since it may have been a defective one.

So now with the complete picture it looks like the cause is the new caliper. You may need to replace that rotor again if that got fried again.

-jim

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Be aware that the rotor on the side that is having problem is most likely ruined again. I wouldn't replace it until the problem has been resolved, but with all this heat that rotor is most likely warped again.

It could be that the brakes were having dragging problems from the time they were fixed but you didn't notice until the rotor finally warped.

Steve B.

I read through most of the posts before responding.

It is very unlikely that a master cylinder is causing the problem, and it is unlikely that a misadjusted push rod is causing the problem unless someone messed with the master cylinder or pushrod.

It is possible, but not likely that a bad wheel bearing is causing the problem. Wheel bearings generally make a lot of noise before getting bad enough to actually cause a problem.

A wheel or tire that is out of round either laterally or radially will cause a vibration, but not likely that the vibration will come and go and it will not make the wheel hot to the touch or bind the brakes so that is not high on my list.

A bad CV joint will make noise, cause pulling, or fling grease all over the undercarriage before it causes an intermittent vibration and will not make the wheel hot to the touch or bind the brakes.

If replacing the calipers did not change the problem, I would have guessed a bad brake hose.

I read that you are replacing the front calipers, make sure that the slides are free and coated with disc brake grease or anti-seize.

Where are you located?

Our resident Toyota resident lashed out at me for saying that was the LEAST likely culprit. Because this is coming in snippets as opposed to a full story, I have to work with SOME assumptions. Among them being that with new tires that the rotors did NOT appear discolored or gouged, there was nothing apparent about the pads. Perhaps giving credit where it isn't due - that a competent dynamic balance was done. Next stage would be to have the rotors MIC'd just to be sure they are round in both planes. Look at the spindle closely. If the spindle is clean, have somebody check out the CV joint and shaft.