ABS Problem?

[rasclaat_98]

Hello all, I have a 1989 Supra non-turbo of which I'm the original owner. The
car all of a sudden started to pull violently to the left when the brake pedal
is pressed at speeds of 80mph and above. It does not do this at normal
speeds, only when i drive fast and suddenly press on the brake pedal. The
best way I can describe the symptoms is that it has a glazing feeling to the
brakes, almost as if the rotors were not gripping the brake pads. The only
way to stop it is to pump the brake pedal repeatedly until speeds reach
below 80mph. To correct this problem I've done the following but still the
problem persists.
1. Replaced front ABS Sensors (2) Replaced ABS computer with a used
one (3) Replaced brake lines (4) Replaced front rotors, brake pads and
calipers.

In an attempt to isolate the problem, I disconnected the ABS computer and
drove the car and it stopped just fine, without pulling to the left as before.
Not sure what the problem could be so any help you guys could provide
would be appreciated. Needless to say, my local Toyota dealership has no
clue as to the problem, nor has any of the many mechanics that I've taken
it to for diagnosis. Again, it brakes fine with ABS disconnected, and only
happens at speeds of 80mph and above.

[mrnickleye]

Well...abs is not my strongest area of expertice, but after reading your post, if it were mine, I might go ahead and replace the sensor in the transmission that measures the rear wheel speed.
(since you've already done the others, and a little more $$ won't hurt)

But...is the speed sensor at the speedo head used for abs??

Others that have had (unsolvable) abs problems have simply unplugged the abs computer, and gone on with life. But you are probably like me, and want things to work as they were designed to.

Have you followed all the trouble shooting steps in the TSRM??
http://www.cygnusx1.net/supra/librar.../br/BR_01.html

[rasclaat_98]

No sir, I have not followed up with any trouble shooting steps in the TSRM
as I was relying on my mechanic and Toyota to come up with a diagnosis.
As of right now the car is safely parked in my garage, but it bugs me to no
end knowing that this problem exists. I'll probably spend some more money
on it when Santa Claus delivers the loot to me for Christmas but I do
appreciate your suggestions and will take the TSRM trouble shooting steps
into consideration come next spring.

Thanks again for your suggestions

[supragirl84]

hi im having the exact same problem with my car only its when im at speeds 50 or above and hit the brakes. im still trying to figure out what it is. i talked to someone at a toyota service center today who told me it might be the caliper going out on that side. the abs light hasnt come on and he told me if it was a problem with that the light would be on. im hoping its just the caliper so i can replace those and get it working again. i just had the engine rebuilt and cant even drive it on the highway hope you get yours fixed soon. i know what it feels like.

[supragirl84]

you mentioned you disconnected the abs computer and it was fine. i was thinking about doing that until i can figure out what the problem is. my question is: would the car be drivable on the highway and do you think thats a safe option for the car or would i be better off just trying to replace the lines and caliper? any advice would be appreciated! thanks!

[btwilson86]

Disconnecting the ABS computer will just leave you with standard brakes. So if your problem is a faulty ABS component, then this will likely be ok. If the problem is with the caliper, as the tech suggested, then disconnecting the ABS computer will not benefit you in any way

[supragirl84]

thanks for the help! i'm more than sure now its not the abs. abs light would be coming based on what the manual and others i've talked to suggest. im about to buy the new calipers and replace those so hopefully it works!