Brake/Traction Control

A month or so ago, the rear brakes on my 2000 Silhouette began making sort of a rumbling sound -- usually when letting up slightly on the pedal when fully stopped. I pulled the rear wheels and everything looked fine except it looked like there might be a slight bit of brake fluid on the wheel cylinders. The fluid level looked OK in the master cylinder so I decided to just keep an eye on it for a while.

In the last week, when starting from a dead stop, the TRAC OFF and BRAKE light will sometimes illuminate and stay on until the next time an 'agressive' stop is made. Normal stops don't cause them to go off. There is no loss of braking power and everything seems to work OK, although, in truth, it would be hard to tell if the traction control is actually working unless the roads are slippery.

The TRAC OFF light seems to come on just slightly before the BRAKE light but this could just be due to the order these outputs come on in the processor.

So what do you think? Is there an actual brake problem? Is there a sensor on the brake fluid level? Maybe the level is just low enough that on a a quick take-off the fluid sloshes off the switch and on a fast stop it sloshes back and resets? The ABS light isn't coming on so I'm hoping it's none of the components on the ABS system.

Thanks for your input.

JWS
2000 Olds Silhouette

Since I didn't get a single reply to my earlier question, I took the bull by the horns and figured it out for myself. I filled the master cylinder reservoir and the problem with the brake light and TRAC OFF light went away. Evidently there is a level sensor in the master cylinder and the fluid was low enough to make it intermittent.

So where did the fluid go? Upon closed examination both wheel cylinders were leaknig -- with the one on the driver's side being the worst. One trip to AutoZone got me two new cylinders which were a snap to install but a pain to bleed. Problem solved!

Watch out for those leaky wheel cylinders -- from what I have read, this is a pretty common problem in the Venture/Montana/Silhouette line.

JWS

Your brake fluid fills the calipers to make up the space of your pads wearing out.

when doing a brake job and compressing the pistons - one should watch the master cyl or it can over flow. (cause you are putting the fluid back in the system).