Brake Work? 93 Buick Lesabre... need help

buick
lesabre

#1

I have a 93 Buick Lesabre and the ABS light was coming on and off for about three weeks.
Now it stays on all the time.
Just recently I had the brakes completely lock up on me.
In my car you have to apply pressure to the brakes to even get the car to shift into gear. The car will drive for about a mile and then all of a sudden the brake pedal is completely hard and the car will not roll forward. It does it completely fine in reverse.
My calipers are good and there is no sound of them locking up. The pads are in good condition.
Then after this happened to me twice in a two mile drive, struggling to get it home… now a light in the dash flashes SECURITY.

It is strange and I know my brakes are in good conditon and there is no abnormal wear and tear.

any ides?


#2

@kris10elizabeth … you need to get your vehicle to a good independent mechanic and get this problem sorted out. The vehicle is too dangerous to drive at this point so make sure it’s towed to the garage. Your life and the lives of others is not worth guessing at a cause right now. It’s happening right now and it needs to be repaired.


#3

Inspect brake hoses from having a wrap-around bracket. The bracket holding the hose can rust inside turning the hose into a one-way valve. Relieve the bracket by spreading open with a screwdriver. The ABS light may be unrelated to the brake dragging problem (bad speed sensor, hydraulic control unit, etc.)

The security light issue is probably unrelated (bad key or bad ignition lock cylinder.)


#4

Pull the fuse for the ABS. The brakes will work normally if the ABS is the problem. You don’t need the abs, it is a good safety feature, but not necessary.


#5

Your '93 Buick’s ABS lacks the ability to apply the brakes, only to interfere with their application. But Knfenmore’s test is a good one nonetheless.

One thing that DOES have the ability to apply the brakes by itself is the brake booster. If functions by using the engine’s vacuum pulling on a diaphragm to help you apply the brakes. The vacuum is relieved from the diaphragm via valves in the booster assembly. If those valves are malfunctioning, or if the brake rod that goes from the pedal through the booster and into the master cylinder is misadjusted such that the valves can’t work properly, vacuum from the engine will continually apply the brakes.

To test the booster, disconnect the vacuum line and clamp it shut (so the engine doesn’t experience a vacuum leak. If the problem disappears, you have a bad booster. Be careful testing this, because you’ll need more force to apply the brakes, so don’t test it next to any schoolyards.

That “need to apply pressure to brakes to shift into gear” is intentional. It’s a safety interlock solenoid. Good to hear it’s working properly.

Post back with the results of the quick-tests.