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Re: 84 Corolla Rear Right Brake stuck
On Mon, 10 Oct 2005 17:42:20 -0400, "Porge" <geogotelli@aol.com>
wrote:
[color=blue]
>Re: 1995 Corolla Brake Problem - Brakes seize up after driving less than
>ten miles and then we have to wait a few hours for them to loosen up and
>be drivable again. Car was in one brake shot for 5 weeks - Master Cylinder
>was replaced and blew twice for repairer. He said he couldn't fix it. Was
>in another brake shop for two weeks and he got it drivable but not
>reliable. Said we needed to go to a Toyota dealership. Shouldn't a "Brake
>Shop" be able to fix this problem. Nearest dealership is over 75 miles
>away down a mountain. Help. Please.[/color]
This is Not brain surgery, a good technician should be able to
figure this out fairly quickly. And the guy who has been working on
this for you is in for a good Homer Simpson style "D'Oh!!" head-smack
when he finally figures it out.
(And you probably should get a partial refund if he was just
guessing at the cause and throwing expensive new parts at your car,
instead of using his head for more than a place to grow hair.)
Sounds to me like they should be looking for a restricted hydraulic
line of some sort. The pressure builds up past the restriction and
locks the calipers or wheel cylinders, and takes time to bleed down.
First trick is to figure out what you are up against. Drive around
the block and get it to lock up sitting in the driveway, then put a
jack under each wheel, pick up and spin the wheel, and see which wheel
or wheels are locking on you. Or that all four are. That will narrow
down the places you need to look.
If all four wheels are locking evenly, it is something common - the
brake failure light valve, a pinched line right out of the Master
Cylinder, or the ABS Control Unit if the car has one. Or they put the
wrong replacement Master Cylinder in.
Or the most likely problem of all so far - they have the brake pedal
linkage pushrod assembled or adjusted wrong, and the pedal doesn't
fully release the master piston when it is released. If the Master
Cylinder main piston doesn't move back to the full release position
the relief ports to the fluid reservoir stay closed, which will build
up pressure at all four wheels and cause exactly the problem you
describe.
Both rear wheels locking only would point to the steel lines going
to the back of the car, or the flex hose between the body and the rear
axle hard lines.
Pickup trucks have a Load Sensing Proportioning Valve on the rear
axle that could be the culprit - the lighter the load, the higher the
rear springs, the valve arm moves down, and the back brakes get
engaged less - a poor man's anti-lock system that actually works.
And only one wheel locking up would point to the hydraulic line to
that wheel. Pinched steel line, or old and failed rubber brake hose.
You do know that old rubber brake hoses that connect the calipers to
the steel lines on the chassis can fail internally without leaking
externally, act like a check valve, and cause exactly the symptom you
describe, right? (But on the one or two wheels it's connected to.)
And a 1984 car is more than old enough to do this. Changing out all
the rubber brake hoses on general principles (I.E. they are rubber,
they are old, and old rubber rots) is cheap insurance. I would do it
even if you find the problem is somewhere else - one of those hoses
bursting can really ruin your day.
And if you drive a Pre-1970's car with a single braking system,
multiply that "Oh, SHIT!!!" factor by 100. If one rubber brake hose
pops, you lose ALL the brakes. That could leave a mark...
--<< Bruce >>--
--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
Spamtrapped address: Remove the python and the invalid, and use a net.
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