Brake warning light on: causes and can you still drive?

The brake warning light is one light for several messages. The ANWB writes that it can point to too little brake fluid, wear of the brake pads or a problem with the ABS system. In the workshop we see these six causes, from harmless to serious:

1. The handbrake is still on or not fully released. With a lever handbrake, the light stays on as long as the lever is not fully down. With an electric parking brake, the light stays on as long as the brake is applied. This is the most common and the most harmless cause.
2. The brake fluid level is too low because of worn brake pads. As the brake pads wear, the pistons in the brake calipers move further out and the level in the reservoir slowly drops. Once it drops below the minimum, a float closes a contact and the light comes on. The system is not leaking, but the pads are due for replacement.
3. The brake fluid level is too low because of a leak. A leaking brake hose, a rusted-through brake pipe, a leaking wheel cylinder or a leaking master cylinder. The level then drops quickly and the brake pedal becomes soft or sinks. This is the dangerous variant.
4. The brake pad wear sensor makes contact. Many cars have an electric sensor in the brake pad. When the lining is nearly gone, the sensor scrapes over the disc and the light or a separate message comes on. Ferodo describes sensors with two levels: a first warning at 70 percent wear and a second at 100 percent.
5. A fault in the electric parking brake (EPB). On cars with an electric parking brake, the light can come on or flash when the actuator on the brake caliper reports a fault. This often comes with a message in the display.
6. A fault in the brake servo, the ABS or the brake force distribution. On many cars the red brake light comes on together with the yellow ABS light when the ABS unit detects a fault that also affects the brake force distribution. The brake servo (which boosts the force of your foot on the pedal) can also give a warning. The pedal then feels hard.

Red means stop, yellow means drive on at reduced speed. That is the general rule the ANWB uses for all dashboard lights: with a red light you must stop and pull over at once, with a yellow or orange light you can drive on for a while. For the brakes there are three lights that are often confused:

Symbols differ per make. Check the owner’s manual of your car to see which symbol belongs to which light.

If only the yellow ABS light is on, the car still brakes normally according to the ANWB, but the ABS no longer steps in during an emergency stop. The wheel sensors are the most sensitive part. You can read all about that light in ABS warning light on. Please note: for passenger cars first registered after 31 December 2017, an ABS light that stays on means the car fails the APK (MOT), the compulsory periodic vehicle inspection in the Netherlands, according to the APK manual of the RDW, the Dutch vehicle authority. If the red brake light and the yellow ABS light are on at the same time, treat it as red: stop and check. What the other lights on your dashboard mean, sorted by colour, is explained in our guide to dashboard warning lights.

That depends on what you see and feel. Stop the car in a safe place and go through these three steps:

1. Is the handbrake fully released? Push the lever all the way down or release the electric parking brake. If the light goes out, this was the cause and you can drive.
2. What is the brake fluid level? Open the bonnet and look at the transparent reservoir, usually on the driver’s side against the bulkhead. The level must be between MIN and MAX. If it is below MIN and you see wet patches near a wheel or under the car, there is a leak.
3. How does the brake pedal feel? Press the pedal while stationary. If it feels normal and firm, you can drive gently to the garage. If it feels soft or spongy, slowly sinks or you have to pump it, do not drive on.

Do not top up the reservoir without thinking. If the level is low because of worn brake pads, the reservoir will overflow as soon as the new pads are fitted and the pistons are pushed back. If it is low because of a leak, topping up solves nothing. And according to the ANWB, DOT 5 must not be mixed with DOT 3, DOT 4 or DOT 5.1. Which brake fluid belongs in your car and how often it has to be changed is explained in brake fluid change.

A soft pedal combined with the brake warning light almost without exception points to a leak or to air in the brake system. Brake fluid cannot be compressed: when you press the pedal, the pressure goes straight to the brake calipers. If there is air or vapour in the line, or if fluid is leaking away, you first compress that air and the pedal feels spongy.

The ANWB names the same symptoms for a faulty master cylinder: a soft or spongy brake pedal, a pedal that slowly sinks, sometimes visible leakage and a brake system warning light that is on. Other causes are a leaking brake hose, a rusted-through brake pipe (a fail at the APK if it has pitting corrosion) or old brake fluid that has absorbed moisture. Because of that moisture the boiling point drops and, according to the ANWB, vapour bubbles can form while braking. More about the causes is in spongy brake pedal and in brake hoses and lines. In all these cases: do not drive on.

We start with reading the fault codes and measuring, not with replacing. A brake warning light has several possible causes and we want to find the right one before we do anything to the car. This is how we go about it:

1. Reading fault codes: with the diagnostic tool we read the fault codes from the brake system, the ABS and the electric parking brake. That tells us whether it is a sensor, the fluid, the parking brake or the brake servo.
2. Brake fluid: we check the level and, if it is low, look for leaks at the wheels, the hoses, the pipes and the master cylinder. We check the brake fluid and change it according to the manufacturer’s schedule, usually every two years.
3. Measuring pads and discs: we take the wheels off and measure the thickness of the pads and discs. We compare that with the manufacturer’s minimum. The minimum thickness of the disc is marked on the disc itself (MIN TH).
4. Wear sensor: if the sensor is the cause, we replace the brake pads per axle and fit the new sensor with them. We do not replace a sensor on its own without measuring the pads.
5. Handbrake and parking brake: we check the handbrake cables (a cable with one broken strand is a fail at the APK) or put the electric parking brake into service mode with the diagnostic tool to assess the rear brakes.
6. Testing: after the repair we test the brakes on the brake tester and take a short test drive. Only then do we clear the warning.

We tell you in advance what we have found and what the repair costs, and we only repair with your approval. If we replace brake pads or discs, you can see the old parts. How we work and what is included in the price is on brake replacement in Rotterdam.

A brake warning light that is on because of the handbrake or a low fluid level is not listed as a separate fail in the APK manual, but the cause behind it usually is. On passenger cars first registered after 31 December 2017, the warning for the braking system must also not indicate a fault. According to the RDW APK manual, the inspector checks that the brake fluid level is not below the minimum mark and that the filler opening is closed with a proper cap. He looks for leaks, at the hoses and pipes, at the brake discs and he tests the braking force on the brake tester. For passenger cars first registered after 31 December 2011, a minimum braking deceleration of 5.8 m/s² applies, and the difference between left and right on one axle may not be more than 30 percent of the highest measured braking force.

A separate rule applies to the ABS: on passenger cars first registered after 31 December 2017, the ABS warning may not indicate a fault. An ABS light that is on is therefore a fail on those cars. If the brake pads are nearly worn out, the inspector may note an advisory. If you take the car to the APK with a red brake warning light on, there is a good chance it will fail on the cause. Better to have the cause fixed beforehand. What the inspector checks on the brakes is explained in failed the APK on the brakes.

No. Not without stopping and checking first. The ANWB writes that with a red light you must stop and pull over. If the handbrake is off, the brake fluid is between MIN and MAX and the pedal feels normal, you can drive gently to the garage. If the pedal is soft or you see a leak, have the car brought in.

Then check the brake fluid level. If it is below MIN, the brake pads are worn or the system is leaking. If the level is fine, it is probably the brake pad wear sensor or a fault that can only be found with the diagnostic tool. Call us and we will schedule a short brake check. If nothing needs doing, we tell you that too.

No. Better not. A low level has a cause: worn brake pads or a leak. Topping up hides that cause, and with new brake pads the reservoir will then overflow. In addition, according to the ANWB, DOT 5 must not be mixed with DOT 3, DOT 4 or DOT 5.1. Have the level and the cause checked in the workshop.

That is often a level that sits right on the limit. In bends or when braking, the brake fluid sloshes in the reservoir and the float briefly touches the contact. The brake pads are then usually nearly worn out. A wear sensor that is beginning to scrape gives the same picture. Have the brake pads measured soon.

No. Not necessarily, but often it does. Worn pads make the brake fluid level drop or trigger the wear sensor, and in both cases the light comes on. The light also comes on with a handbrake that is on, with a leak and with a fault in the ABS or the parking brake. We measure the thickness of the pads before we replace anything.

That depends on the cause. If it is the handbrake, no repair is needed. If it is the brake pads, it is a set per axle including fitting and testing. With a leak or a fault in the ABS it varies. We do not quote our own prices on this page: we tell you one price in advance based on your registration number. Market indications from the ANWB and what is included in the price are in brake replacement cost in the Netherlands.

Yes. An electric car has the same hydraulic brakes, the same brake fluid and usually an electric parking brake. The light works the same way. Because the mechanical brakes of an EV are used less, the brakes rust sooner and a brake caliper can seize, according to the ADAC. Our mechanics are GMTO-certified for hybrid and electric cars.

• ANWB: Waarschuwingslampjes op het dashboard: red brake light and the rule red versus yellow (in Dutch)
• ANWB: ABS: what happens when the ABS light is on (in Dutch)
• ANWB: Hoofdremcilinder: soft pedal, sinking pedal and leakage (in Dutch)
• ANWB: Remvloeistof: level, warning light, DOT types and interval (in Dutch)
• RDW: APK manual passenger cars: braking system, articles 5.2.31, 5.2.32 and 5.2.38 (in Dutch)
• Ferodo: Brake Warning System: wear sensor with two levels