ABS and Brake Light on 98 Century

[Sandor]

Hi, I just got this car today from a dealer, it's a 98 Century with 48k miles, NO WARRENTY. When I started the car, after driving it home, the ABS and Brake dash board warning lights came on. This is what I've noticed. If I just start the car they come on and stay on. If I put my foot on the brake and start the car they are off until I release my foot at which time there is a clicking from the master cylinder or very close to it. It clicks about 5 times then the warning lights come on.

If I drive the car and shut off the engine while in drive still rolling, put my foot on the brake just a bit, shift to neutral start the car, and shift back into drive, the light's go off and stay off as long as I keep the engine running. The lights will stay off even if I stop, put the car in park and then drive again. They only come back on when I shut off the engine and restart.

I can turn a wrench, but don't know the first thing about ABS, please any help is appriciated.
Sandy

[BNaylor]

Originally Posted by Sandor

Hi, I just got this car today from a dealer, it's a 98 Century with 48k miles, NO WARRENTY. When I started the car, after driving it home, the ABS and Brake dash board warning lights came on. This is what I've noticed. If I just start the car they come on and stay on. If I put my foot on the brake and start the car they are off until I release my foot at which time there is a clicking from the master cylinder or very close to it. It clicks about 5 times then the warning lights come on.

If I drive the car and shut off the engine while in drive still rolling, put my foot on the brake just a bit, shift to neutral start the car, and shift back into drive, the light's go off and stay off as long as I keep the engine running. The lights will stay off even if I stop, put the car in park and then drive again. They only come back on when I shut off the engine and restart.

I can turn a wrench, but don't know the first thing about ABS, please any help is appriciated.
Sandy

Does your Century have the traction control system? If so does the trac off light come on too?

The BRAKE light indicates either the parking brake is not properly released or there is a hydraulic system problem with the brake system. It could be something as simple as low fluid level.

The clicking sound is the ABS calibrating or intializing itself. However, it appears to be failing during self test and triggering the ABS light.

[Sandor]

no other warning lights.
checked the fluid it is full.
When I slam on the brakes, the Low Trac light comes on.
The manual indicates this will happen when the ABS kicks in.
I made sure the parking brake is fully released. Still have
both ABS and Brake warning lights on.

Went to Auto Zone, no help, they don't check codes for ABS.

[BNaylor]

Originally Posted by Sandor

no other warning lights.
checked the fluid it is full.
When I slam on the brakes, the Low Trac light comes on.
The manual indicates this will happen when the ABS kicks in.
I made sure the parking brake is fully released. Still have
both ABS and Brake warning lights on.

Went to Auto Zone, no help, they don't check codes for ABS.

The shop has to have a scanner/code reader with the capability to scan for GM manufacturer specific CHASSIS codes in which ABS is a part of.

Many ABS problems are the wheel sensors but your symptoms are somewhat different. I'll check my Regal service manuals and see if I can help shed some light on the problem.

[BNaylor]

*****FOLLOWUP ANSWER*****

Good news and bad news. When the ABS light illuminates the system switches to conventional braking. The ABS is out of the picture.

However, when both the ABS and BRAKE lights illuminate together it indicates a conventional braking system problem hydraulic failure.

Therefore, the conventional braking problem must be resolved or fixed first and chances are the ABS will then work normally too. Possibilities are the master cylinder, excessively worn brakes pads or air in the system which will require bleeding.

[Sandor]

Dealer said it was the motor, so I paid the $500 and had it replaced. The lights are off, until ???
Thanks for all the help. If more develops I'll post it.