The red brake warning light has been around since the early cars. Don’t confuse the red brake light with an amber ABS or brake light. An Amber ABS light signifies a problem with the electronic Anti-lock Brake system. The red brake light signifies a problem with the general hydraulic brake system which, since it’s red, means it’s serious.
Typically a red brake light that stays on while the car engine is running means there is a serious loss of hydraulic pressure. However, this is the ONLY warning light that can have 2 or 3 totally different meanings.
Troubleshooting Brake Warning Lights
For whatever reason, engineers early on used the same red brake warning light to alert the driver the parking brake is on. To tell the difference is quite simple. Just like with rear vehicle lighting, we all know that a brighter red light in the rear means the vehicle is applying the brakes compared to the tail light intensity. The red brake warning light works the same. If the red warning light is on, you can apply the parking brake and watch to see if the intensity changes. The parking brake will make the light get brighter. If it doesn’t change intensity, then it may be a parking brake problem.
If it is determined that it is not due to the parking brake being applied, it could be due to the brake fluid level being low. Typically, if the level is low enough to cause the light to illuminate, there is a reason that should be investigated. Yes, adding fluid may make the light go out but that just “puts a bandage” on the symptom.; kind of like taking aspirin to dull pain but not fixing the true cause of the pain.
The most serious reason the red brake warning light will come on and stay on is if it the brake system has lost hydraulic pressure. Typically, the driver will also experience a very low brake pedal or the vehicle not wanting to stop that will also indicate a problem with the hydraulic pressure. At that point, it’s a problem that is serious enough to warrant a tow.
Brakes get applied thru hydraulic pressure and when pressure drops for whatever reason (usually due to a brake fluid leak), the brake system will not function. Bottom line, when the red brake light stays illuminated after the engine starts, you should make it a priority to investigate the cause.
Major points to remember about the red brake warning light:
1) It is a bulb check light during key on engine off. It will go out after engine starts if all systems it monitors are OK
2) It will become brighter if the parking brake is applied. It is an inherent design to give the driver the ability to determine if the light is on due to the parking brake applied or something else.
3) Most common cause for the light to come on is due to fluid level low. This is usually due to worn brake pads (may need replacement) but can be due to a leak.
4) If it comes on due to loss of pressure, you will typically feel it in the pedal being “spongy”. This is serious and may warrant a tow to a repair shop
5) Some imports designed the red brake warning light to come on due to a charging system malfunction. If this is the case, they also had the battery light illuminate at the same time. It was there way of alerting a driver that a vehicle not charging is a serious problem that needs to be addressed as soon as possible. Domestic cars never designed there systems to do that.
6) Falls under the general red light scenario. If it’s red, it need immediate attention.
Wise Auto Clinic is an ASE certified shop that can troubleshoot and diagnose your brake light problems. We will give you an honest assessment of the problem and a competitive price quote to repair it. We stand behind all our work with a 12 month/12,000 mile nationwide warranty. Contact us to schedule your appointment today!