Brake Warning Light Comes On

Reader Question

Hello Austin:

I am sure you have heard this before but as a single woman I am afraid to take my car in for service. But to cut to the chase I have a 1997 Toyota 4runner. Four times now the Brake light has come on on the console and the car has made a horrible grinding noise as soon as I start it up. It lets me drive it and the brakes feel fine.

The noise lasts from 1 minute to 5 minutes this last time. I took it in and he said that he could not tell if the Master cylinder was going bad but the brakes looked fine. They are the original brakes on the car. He did adjust the rear brakes. What should I do?
Thanks, Catherine

Hi There Catherine

Thanks for the email. Is it the red brake warning light that comes on, or is it the yellow “bulb out” indicator also called “lamp failure” light?

If the RED brake light comes on the dash, it usually means that the brake pedal has traveled or been pushed too far down. If the brake pedal is pushed to the floor it would indicate that there is no fluid in the system to operate the brakes. So, when the red light comes on it is generally a low brake fluid type of problem.

Low brake fluid can be caused by an external leak in the brake system or from an internal failure in the master cylinder (the part under the hood on the driver side firewall where you pour in the brake fluid) or other internal brake part failure.

So, when the brake system is low or out of brake fluid the brake pedal will feel soft and will travel low to the floorboard. Once the fluid is completely out of the system, you will not have the use of the brakes until the brake fluid has been reinstalled…you say this is not happening.

If the red light is coming on intermittently, I would first inspect the level of brake fluid in the master cylinder, and top off as needed. It might be just low enough to turn on the light. Like when you make a hard stop or hard turn and the fluid is tilted to one side of the master cylinder just enough to turn on the dash light until the fluid settles back down.

If the master cylinder is full of brake fluid, I would probably lean towards replacing the master cylinder to correct the warning light problem.

If your brake noise is also intermittent and seems predominately worse the first few stops you make in the morning or after the vehicle has been sitting a few hours I would think the noise is probably coming from the front brake pads themselves and is not directly related to the brake warning light.

Japanese vehicles are extremely finicky about the brand of brake pad that is used. I have not had much luck with “aftermarket” non Toyota brake pads and brake squeals like I think you are describing.

If the noise goes away after the first few stops, and might only “squeal” once or so through out the day as the pads get hot…I would suggest replacing the front brake pads with pads purchased from the Toyota dealership.

If it is JUST brake squeal, continuing to drive the vehicle will not cause any damage. You might want to wait until the brakes are worn down enough to warrant replacing them with dealer pads?

Please share this with your friends,

Austin C. Davis