Replacing a brake light bulb takes 15 to 30 minutes and requires only a screwdriver and the correct replacement bulb

A brake light bulb burns out when you press the pedal and one of the rear lights does not glow, or when you notice it is dimmer than the other side. The bulb itself is inexpensive — usually between $5 and $15 — and you can replace it without a mechanic. The process is the same whether you drive a sedan, SUV, or truck: access the housing from inside the trunk, unscrew or unclip the assembly, twist out the old bulb, and install the new one.

The hardest part is usually finding the right bulb type for your vehicle. Brake light bulbs come in different sizes and bases, and using the wrong one means it will not fit or will not work. Your owner's manual lists the correct bulb number, or you can look it up online using your vehicle's year, make, and model.

Key Takeaways

  • Brake light bulbs are identified by a number code (like 1157 or 7443) that you must match exactly when buying a replacement.
  • Most brake light housings are accessed from inside the trunk and held in place with screws or plastic clips that take seconds to remove.
  • The bulb itself twists counterclockwise out of the socket and twists clockwise back in — no tools needed for this step.
  • Test both brake lights before closing the trunk to confirm the new bulb works and you installed it in the correct position.

Locate the correct bulb type before you start

Open your owner's manual and search for "brake light bulb" or "light bulb specifications." The manual will list a number code — common ones are 1157, 1156, 7443, 7440, or 3157. Write this number down. If you do not have the manual, search online for "[your year] [your make] [your model] brake light bulb" and you will find the code within seconds.

Go to an auto parts store or order online using this number. The staff at the counter can also look up your vehicle if you give them the year, make, and model. Buy two bulbs if the store sells them in pairs — it is cheaper than buying one, and you will have a spare if the other side burns out soon after.

Open the trunk and locate the brake light housing

Park on a level surface and open the trunk. Look at the inside of the rear panel, directly behind where the brake lights are mounted on the outside of the car. You will see a plastic or metal housing that protrudes slightly into the trunk. This is the brake light assembly.

On some vehicles, the housing is obvious and straightforward to reach. On others, you may need to remove a trim panel or move aside a carpet flap to access it. If you cannot see it clearly, check your owner's manual for a diagram showing the location in your specific vehicle.

Remove the brake light housing from the car

Look for screws or plastic clips holding the housing in place. Most cars use either two or three screws on the outside edges of the housing, or plastic tabs that you push or pull to release. Use a Phillips or flathead screwdriver (whichever matches the screw head) to unscrew the fasteners, or use your fingers to unclip the plastic tabs.

Once the fasteners are loose, gently pull the entire housing toward you and out of the car. Be careful not to yank on any wires connected to it — the wires are fragile and can break. The housing should slide out smoothly once the fasteners are removed. Set it on a clean surface where you can work without dropping it.

Twist out the old bulb and install the new one

Look inside the housing and you will see one or more bulb sockets. Each socket holds a bulb that twists in and out. The brake light socket is usually the larger or brighter one — if you are unsure which one is the brake light, your owner's manual will show you.

Grasp the bulb gently and twist it counterclockwise (to the left) until it comes free from the socket. The bulb will slide out easily once it has twisted about a quarter turn. Do not force it. Insert the new bulb into the same socket and twist it clockwise (to the right) until it is snug. You will feel a slight resistance when it is seated correctly — do not over-tighten.

Reinstall the housing and test the lights

Slide the housing back into the car, aligning it with the mounting holes or clips. Screw the fasteners back in or push the plastic tabs until they click into place. Make sure the housing is seated flush against the car body and does not stick out or rattle.

Have someone sit in the driver's seat and press the brake pedal while you stand behind the car and watch both brake lights. The new bulb should glow brightly and match the brightness of the other side. If it does not light up, turn off the car, remove the housing again, and check that the bulb is twisted all the way in. If the bulb is in correctly but still does not work, the socket itself may be damaged — this is rare, but if it happens, take the car to a mechanic to have the socket replaced.

Once both lights work, close the trunk and you are finished.

Frequently Asked Questions

Can I replace a brake light bulb without removing the housing?

On some vehicles, you can reach the bulb socket from inside the trunk without removing the entire housing. Look for a rubber access cover or a socket that twists out from the back. If you can see and reach the socket, you can replace the bulb without unscrewing anything. Most cars, however, require you to remove the housing for safe access.

What if the new bulb does not fit in the socket?

You bought the wrong bulb type. Double-check the number code on the bulb against your owner's manual or the code you looked up online. Return the bulb to the store and exchange it for the correct one. Do not force a bulb that does not fit — it can break inside the socket and be difficult to remove.

How do I know which socket is the brake light and which is the turn signal?

Your owner's manual includes a diagram showing which socket is which. If you do not have the manual, look at the bulb sockets themselves — the brake light socket is usually larger or positioned differently than the turn signal socket. When in doubt, ask the staff at an auto parts store to show you using your vehicle's manual.

Do I need to disconnect the battery before replacing a brake light bulb?

No. Brake light bulbs operate on low voltage and are safe to handle and replace without disconnecting the battery. You do not need any special tools or precautions beyond a screwdriver and the correct bulb.