Brake light bulbs burn out faster than other vehicle lights because they cycle on and off constantly in traffic

A brake light bulb typically lasts between 20,000 and 200,000 miles depending on your driving habits and how often you brake. Unlike headlights that stay on for long stretches, brake lights flash repeatedly, which shortens filament life. When one burns out, the other side still works, so you might not notice until a police officer or another driver points it out — or until you get a ticket.

Replacing a brake light bulb is one of the simplest maintenance tasks you can do yourself. Most vehicles let you access the bulb from inside the trunk or cargo area without removing the entire light assembly. The whole job usually takes 5 to 15 minutes, costs $5 to $15 for the bulb, and requires no special tools beyond what you already have at home.

Key Takeaways

  • Brake light bulbs burn out from repeated on-off cycling, not from age alone, so check yours every few months if you drive in heavy traffic.
  • Most vehicles let you access the bulb socket from inside the trunk by twisting out a plastic housing or removing a trim panel.
  • The correct bulb type is printed on the socket itself or in your owner's manual — common sizes are 1157, 1156, and 7443.
  • You can test whether the bulb is actually burned out by turning on the headlights and having someone watch the brake lights while you press the pedal.
  • If both brake lights are out, the problem is usually a blown fuse or bad switch, not two burned bulbs at once.

Locate the brake light housing from inside your trunk

Open your trunk and look at the inner wall where the brake lights sit on the outside. You will see either a plastic housing that twists counterclockwise or a trim panel held by clips or screws. Some vehicles have a single large panel covering both lights; others have separate housings for left and right.

Consult your owner's manual if you cannot when ready spot the housing — it will show you exactly which panel or socket to access. The manual also tells you whether you need to remove anything else first, like a cargo cover or wheel well liner. On some trucks and SUVs, you may need to open a small access door on the inside of the tailgate rather than working from the trunk.

Remove the bulb socket and identify the correct replacement

Once you have located the housing, grip the plastic socket firmly and twist it counterclockwise about a quarter turn. The entire socket should pull straight out toward you, bringing the bulb with it. Do not force it — if it does not turn easily, you may be turning the wrong direction or gripping a different part of the assembly.

Look at the base of the socket. A number is printed there — this is the bulb type. Common brake light bulbs are 1157 (two-filament, used for brake and running lights), 1156 (single-filament), and 7443 (modern wedge-style). Write down this number before you go to the store or order online. The bulb itself may still be in the socket; if so, you can pull it straight out by hand or with gentle pressure.

Purchase the correct bulb and test the old one first

Buy the bulb type that matches the number on your socket. Brake light bulbs cost $3 to $12 each depending on brand and whether you choose standard or LED. Standard incandescent bulbs are cheaper and work in any vehicle; LED bulbs last longer but may not work in older vehicles with certain electrical systems.

Before you install the new bulb, test the old one to confirm it is actually burned out. Hold the old bulb up to a light source and look at the filament inside the glass. A burned-out bulb will have a broken or blackened filament. If the filament looks intact, the problem may be a blown fuse or a bad brake light switch instead — in that case, replacing the bulb will not fix the issue, and you should have the electrical system checked.

Install the new bulb and reinstall the socket

Push the new bulb straight into the socket until it seats fully. You should feel a slight resistance as it clicks into place. Do not twist or force it — brake light bulbs insert straight in, unlike some other automotive bulbs that require a quarter-turn.

Reinsert the socket into the housing by aligning it with the opening and twisting clockwise until it stops. You will feel it catch and lock into place. Do not over-tighten — a firm quarter-turn is enough. Close the trunk and test the brake lights by having someone stand behind the vehicle while you press the brake pedal. Both lights should illuminate equally.

What to do if the new bulb does not light up

If you installed a new bulb and it still does not light, the problem is not the bulb itself. Check whether the other brake light on the same side works — if both are out, you likely have a blown fuse. Locate your fuse box (usually under the dashboard or in the engine bay; your manual shows the location) and look for the brake light fuse. If it is blackened or the wire inside is broken, replace it with a fuse of the same amperage.

If only one light is out and the fuse is good, the issue is usually a bad brake light switch or a wiring problem. The brake light switch is mounted near the brake pedal and sends power to the lights when you press the pedal. A failing switch will not send that signal, so no bulb will light no matter how new it is. This requires a mechanic to diagnose and repair.

Prevent premature burnout by checking your lights regularly

Brake light bulbs fail without warning because you cannot see them from the driver's seat. Set a reminder to check them every three months by walking around your vehicle at night with the headlights on and the brake pedal pressed. Look for any lights that are dimmer than the others or completely dark.

If you live in a humid climate or park outdoors, moisture can corrode the socket contacts and cause bulbs to burn out faster. If you replace a bulb and it burns out again within a few weeks, the socket may be corroded. Clean the socket contacts with a pencil eraser or fine-grit sandpaper, or have a mechanic inspect the connection.

Frequently Asked Questions

Can I use an LED bulb in my older vehicle?

LED bulbs work in most vehicles made after 2000, but some older cars have electrical systems that do not recognize LED bulbs and will trigger a warning light or cause the bulb to flicker. Check your owner's manual or ask at the parts store whether LED bulbs are recommended for your year and model. Standard incandescent bulbs always work as a backup.

What if I cannot get the socket to twist out?

explore gentle pressure and twist slowly — forcing it can crack the plastic. If it still will not budge, try twisting in the opposite direction; some vehicles use clockwise instead of counterclockwise. If you are still stuck, consult your owner's manual or a repair video specific to your vehicle year and model before you risk breaking the housing.

Do I need to replace both brake light bulbs at the same time?

No. Replace only the bulb that is burned out. However, if both bulbs are out, do not replace them both — check the fuse and brake light switch first, because two bulbs rarely burn out simultaneously unless there is an electrical problem.

How long does a new brake light bulb last?

Standard incandescent bulbs last 20,000 to 200,000 miles depending on your driving habits. LED bulbs last much longer, often 50,000 miles or more. Heavy traffic with frequent braking will shorten the life of any bulb because the filament cycles on and off more often.