Re: HELP: 93 Toyota Corolla vibration problem!

"Mike" <mik@[EMAIL PROTECTED]
> wrote in message 
news:Pa8Qj.2038$NU2.35@[EMAIL PROTECTED]
>>>>>>>>>> Replace both front brake hoses, replace the brake fluid, and 
>>>>>>>>>> bleed the
>>>>>>>>>> brakes.
>>>>>>>>>
>>>>>>>>> Ray, I had them do this.  The problem still persists.  Could it
be 
>>>>>>>>> a
>>>>>>>>> brake booster problem?
>>>>>>>>
>>>>>>>> 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?
>>>>>>>
>>>>>>> I will add one additional possibility that I personally
experienced 
>>>>>>> on an
>>>>>>> Acura TL.  A bad upper ball joint caused ALL the symptoms re****ted

>>>>>>> here on
>>>>>>> that car - hot wheel, apparent warping of the rotor, chattering 
>>>>>>> brakes,
>>>>>>> all
>>>>>>> of it.
>>>>>>
>>>>>>
>>>>>> You know, IF a wheel threw a weight off it could do the same thing.
>>>>>>
>>>>>>
>>>>> Throwing a weight causes a constant vibration.  This was different
and 
>>>>> was
>>>>> confirmed to be the ball joint on the TL.
>>>>
>>>> Usually throwing a weight will cause vibration at certain speeds. 
>>>> Depends on the size of the wheel weight. Big ones act more harshly
when 
>>>> missing than small ones. Remember he said the wheel DOES have a small

>>>> wobble to it. Maybe move a rear wheel up front. Try that for a couple

>>>> days.
>>
>>>  Would a missing wheel weight also cause the brakes to apply and make 
>>> the vehicle slow down ???  That's what he stated is also happening.
>>
>>    Did he say the brakes APPLIED?

>  YES. He mentioned it many times. Like here:
> Now here is what I think, although i'm not a mechanic... I think it
> has something to do with the front passenger-side caliper.  It may be
> locking up somehow.  But i noticed on local roads before the vibration
> starts, if the pedal is stiff, pump it a few times and it goes away...

    No that's not excaltly whay he said. I can understand how you could
read 
it that way. Hut it isn't exactly what he said. It MAY well be the
caliper, 
but it can be either one of them or both. There are several other options
as 
well.

> And here: Well, the rotor was bluing, which is why i replaced them about

> 1000
> miles ago.  But, I think that is the symptom and not the disease.
> What can be causing the dragging?

    The word "draggin" doesn't mean it WAS the brakes being on. It CAN but

it can also be something else.

> And here: I did not have to use my brakes at all for the entire
> highway ****tion of the trip, but it still started to drag and then
> vibrate half way into the trip.  Please notice that i said it drags
> THEN vibrates.  You can feel that you need more gas pedal effort to
> move the car and then the vibration starts gradually shortly
> thereafter and builds up in intensity

    Try to re-read that without being so dogmatic. Don't get too invested
in 
a single solution.

> And here:
> 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.

    Does that mean the brakes were dragging? It MAY. But not necessarily.

> And here:
> Thank you to everyone that has helped me thus far.  These symptoms
> aren't new... but just better described than previously.  Please
> review:

> 1. Brake drags occasionally not all the time and the dragging can
> start without the use of the brake pedal (once i was driving on an
> empty highway at 3AM for 30 miles, and it just started dragging).

    <sigh> How does he know that?  Hear it?

> 2. once the drag starts, it gets progressively worse.  I'm not sure if
> the heat causes it to lock up more, or if it just locks up more and
> causes more heat (Chicken or Egg?)  But you can feel that more and
> more gas pedal effort is needed.
>
> 3. at its worse, there is so much drag that the car will not idle
> forward from a stop.
>
>
>  Those were all taken from seperate posts.
>
>
>>That isn't what I read.

>  Well whos fault is that ??

    No fault here. I just prefer to eliminate all the easy stuff first,
the 
stuff that's easy to check for free before tearing a car apart. It MIGHT
be 
a bad caliper. Like I said from my time in the parts business, rebuilt
parts 
are problem children. I am assumiong that he did NOT go out and buy NEW 
parts from the Toyota Dealer at 10X the price of a rebuilt on a 15 year
old 
car with almost 300,000 miles on it. I don't know WHY .. Silly me. Most 
people willing to shell out $300 per for NEW calipers most likely would be

driving a newer car. JUST A SUSPICION.


>> We all with have 20/20 hindsight when the problem is traced down. Right

>> now all we all can do is guess.

>  Wrong ! There should be no "guessing" involved. He needs to take it to 
> someone who is capable of "diagnosing" the problem, only then can it be 
> repaired. You can only go so far with the "shotgun" method of repairs 
> without spening a small fortune.

    Maybe you MISS that he HAS taken it to a mechanic SEVERAL 
TIMES.................................................