Re: HELP: 93 Toyota Corolla vibration problem!

" krp" <krp2457k@[EMAIL PROTECTED]
> wrote in message 
news:LnYNj.48533$tw3.16015@[EMAIL PROTECTED]
>
> "Ray O" <rokigawaATtristarassociatesDOTcom> wrote in message 
> news:1KKdnfi__tcjSprVnZ2dnUVZ_j-dnZ2d@[EMAIL PROTECTED]
>
>>> I had the tires changed out for brand new Yokoham Avid TRZ.  they were
>>> under warranty so it didn't cost me anything.  However, the vibration
>>> still persisted.  The new additional symptoms are as follows:
>>>
>>> 1. when the vibration occurs, you can get out of the car and feel the
>>> temperature of the steel wheels.  The Passenger Front wheel is hot to
>>> the touch and will burn you.  the rest are cool to the touch.
>>>
>>> 2. the brake pedal has less travel and feels stiffer.
>>>
>>> 3. more gas pedal effort and reduced gas mileage during periods of
>>> vibration.
>>>
>>> 4. this problem will start randomly and is not dependent on if you are
>>> using the brakes.  I was on the highway at 1AM and didn't use the
>>> brakes for 30 miles and it still started.
>>>
>>> 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...
>>> ie the brakes unlock.  The weird thing is I put brand new calipers in
>>> there 3k miles ago.... could one be defective?
>>>
>>> Any help or insight would be appreciated.  Thanks.
>>>
>>> -Jon
>>>
>>
>> Replace both front brake hoses, replace the brake fluid, and bleed the 
>> brakes.
>
>    That may not get the problem. Most tire places use a "static
balance." 
> system. Okay for some purposes on newer cars, but this car is 15 years 
> old. Wheels on the 93 Toyota were not exactly the strongest. The wheel 
> needs a dynamic balance and CLOSE inspection to see how true it is 
> running. On the older cars potholes can tend to cause the wheels to
become 
> bent. I'd start there. Also the Corolla of the 90's was famous for bad 
> wheel bearings. We could assume it has disc brakes on the front wheels.
A 
> close inspection of the spindle and the rotor are next. Not knowing how 
> many miles are on the car (generally we can assume over 100,000) at this

> age as a minimum - you have all sorts of culprits along the way as 
> possibles. Maybe even combinations. That's without getting to any 
> suspension parts. Look at the most likely first.
>
> 1. Bent wheel.
> 2. Bad wheel balance.
> 3. Bad bearing.
> 4. Bad rotor or worn spindle.
> 5. Suspension parts. (there are several high failure parts on the
corolla)
>
>    The brake son the Corolla CAN be bad, but have been one of the more 
> reliable things about Toyota. The only question here is how many times
the 
> rotors were turned and how accurately. MANY brake shops are butchers.
The 
> cut rate places often have poorly trained KIDS doing the job. Nobody 
> should be surprised when they screw up. If too much is taken off a rotor

> when it is turned, they get sort of square after a while. As the too
THINK 
> rotor heats up it tends to go our of round.
>
>    Look at the most likely  first. Brake lines are down the list pretty 
> far. Since it is only ONE side that seems to be causing the vibration I 
> would look for the most likely things first. You MAY wind up with a bad 
> brake hose, but I'd look elsewhere first. Besides you can't really tell 
> about the hose even when you remove it. Not unless it is obviously 
> collapsed. Hardening of the brake hose arteries is not impossible, just 
> unlikely.
>
>    You can start to see the problem when you spin up the wheel on the
car. 
> Most tire stores will CHECK the wheel balance OFF  the car for free. 
> Especially the store where you bought the tires.
>
I already suggested, and the OP checked, most of the stuff you listed. 
Most 
tire shops around here use dynamic balancers, and some even have Hunter's 
new Road Force dynamic balancer.

The problem I've seen on some old brake hoses is not hardening, but a 
deterioration of the lining.  The lining flakes off and blocks the line so

when the pedal is released, residual pressure keeps the caliper piston
from 
releasing.
-- 

Ray O
(correct punctuation to reply)