Re: HELP: 93 Toyota Corolla vibration problem!

" krp" <krp2457k@[EMAIL PROTECTED]
> wrote in message 
news:qi_Pj.14858$Zk5.5151@[EMAIL PROTECTED]
>
> "Mike" <mik@[EMAIL PROTECTED]
> wrote in message 
> news:ttTPj.2065$Cn4.968@[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...

 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?


 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


 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.


 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).

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 ??


 He said he felt
> he had to add pressure to the gas pedal. Without being there driving the

> car, my best answer to you is YES. If a wheel is out on the side to side

> axis, it CAN appear at a specific speed that the brakes are on. That's
NOT 
> what's really happening.

  He stated that the car FIRST slows down THEN the vibration starts. Now, 
would a bent wheel cause the car to slow down or would the brakes dragging

cause it to slow down ??


> You can demonstrate this for yourself the next time you are in a car.
Roll 
> down the window and put your hand out. Try different positions for your 
> hand. Flat to the flow of air, then rotate it side to side on the
horizontal 
> axis. If you can look at the instruments at the same time (assuming you
are 
> NOT the driver) you'll see that it actually CAN slow the car down a
little.

   Bull**** !!


> Same if the wheel isn't straight in the rolling axis as the wheel
revolves. 
> Actually there are more than two. They can be affected in all of them. 
> Caster, Camber and so on. Wheel balance, front end alignment. Some
things 
> have been rules out others NOT.


   But it has been stated many times that the brakes are being applied.
This 
has been proven by the fact that the rotor is turning blue from the heat
and 
more throttle has to be applied to maintain speed.

  Now we have to ask what WON"T cause a brake problem.  Will any of these
case 
a brake problem: Caster? NO !, Camber? NO!, Wheel balance? NO!, Alignment
? 
NO! , Bent Wheel ?  NO! , CV Joint  NO!


>
>    I am one, having been a partner in a parts jobber that doesn't have 
> complete confidence in replacement parts. We have a 15 year old car with

> almost 300,000 miles on it.  We also have a couple smart ass dealer
mechanic 
> types here that have ALL the answers. They didn't read that he had
already 
> tried their "SURE FIRE IT ABSOLUTELY IS" stuff and it didn't work.


  Didn't see any posts from anyone who "had ALL the answers". Did see some

good posts from some knowledgable folks who suggested brake hoses or
calipers. 
The brake hoses were tried and didn't fix the problem, nothing else was
done 
at this point.

  There were many not so good suggestions like wheel balance, bent wheel, 
alignment, tires, caster, camber....etc.


  Facts so far: brakes drag on right front wheel turning rotor blue. From
the 
info given it appears to be a brake problem on the right front wheel.
Brake 
hose were replaced but did not cure problem. This should be an easy
problem 
for a knowledgable mechanic to figure out. It's quite obvious that the 
"mechanic" working on the vehicle doesn't have a clue. He needs to take it
to 
someone knowledgable nad get  it fixed right.




> 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.