What you need before you start

Brake light bulbs burn out faster than other car lights because you use them constantly. Replacing one takes 15 to 30 minutes and requires almost no tools — usually just a screwdriver or your hands, depending on your car's design.

Before you open the trunk or hatch, gather what you need: a replacement bulb (the correct type for your car), a flashlight or phone light, and possibly a Phillips or flathead screwdriver. Your owner's manual or a quick online search for your car's year, make, and model will tell you which bulb type to buy — common ones are 1156, 1157, or 3157, but yours may differ.

You do not need a mechanic for this job. The process is the same whether you are replacing the driver's side or passenger's side brake light, and the only real risk is breaking the plastic housing if you force it.

Key Takeaways

  • Brake light bulbs are sold by type number (1156, 1157, 3157, and others), which you can find in your owner's manual or by searching your car's year, make, and model online.
  • The bulb sits inside a plastic housing that either twists out from inside the trunk or is accessed by removing a panel held by one or two screws.
  • Once the housing is out, the bulb itself twists counterclockwise and pulls straight out — do not pull on the wires.
  • Test your brake lights before you close the trunk by pressing the brake pedal while looking in a mirror or asking someone to watch the back of the car.

Locate the brake light housing from inside the trunk

Open your trunk or hatch and look at the inside of the rear panel where the brake lights are mounted on the outside. You will see either a plastic housing that protrudes inward or a panel with screws.

If the housing twists out, grip it firmly and turn it counterclockwise — it will come free in your hand. If there is a panel, use a screwdriver to remove the one or two screws holding it, then pull the panel away gently. Some cars have a small door or cover you flip open instead. Your owner's manual shows which design your car uses, but you can also just look and see what moves.

Remove the old bulb

Once the housing is out and facing you, locate the bulb socket inside. It will be a plastic or metal piece with wires attached. The bulb itself twists into the socket — turn it counterclockwise and it will come free. Do not pull on the wires; pull only on the bulb or the socket.

Set the old bulb aside. If it is blackened inside or the filament is broken, that confirms it burned out. If it looks fine, the socket itself may be corroded or loose, which is a separate problem you may need a mechanic to diagnose.

Install the new bulb

Take your new bulb and insert it into the socket, aligning the tabs or notches on the bulb base with the slots in the socket. Push gently and twist clockwise until it stops — it should be snug but not forced. If it does not turn easily, stop and check that the bulb type matches what your car needs.

Do not touch the glass part of the bulb with your bare fingers; the oils from your skin can cause it to burn out faster or fail. If you have already touched it, wipe it clean with a dry cloth.

Reinstall the housing and test

Slide or twist the housing back into place. If it twists, turn it clockwise until it is snug. If it was held by screws, replace them and tighten them firmly but not so hard that you crack the plastic.

Close the trunk and test the brake light. Sit in the driver's seat, press the brake pedal, and look in the side mirror to see if the light comes on. If you have someone nearby, ask them to stand behind the car and watch while you brake. If the light does not come on, open the trunk again and check that the bulb is fully seated in the socket and twisted all the way in.

What to do if the light still does not work

If the new bulb does not light up, the problem is not the bulb itself. The most common cause is a corroded or loose socket. Try removing the bulb again, twisting the socket itself counterclockwise to see if it comes out, and checking the metal contacts inside for corrosion or debris. Wipe the contacts clean with a dry cloth and reinstall the bulb.

If that does not work, the wiring or fuse for that brake light may be faulty. This is beyond a bulb replacement and requires a mechanic or someone with electrical diagnostic tools. Do not drive with a brake light out — it is a safety hazard and illegal in most places.

Frequently Asked Questions

How do I know which bulb type to buy?

Check your owner's manual — it lists the bulb type by number. If you do not have the manual, search online for "[your car year, make, model] brake light bulb type" and you will find the answer in seconds. You can also take the old bulb to an auto parts store and they will match it for you.

Can I replace just one brake light or do I have to replace both?

You only replace the one that burned out. However, if both are the same age and one just failed, the other may fail soon. Some people replace both at the same time to avoid a second trip, but it is not required.

What if I cannot get the housing to twist out?

Stop and do not force it — you may crack the plastic. Look more carefully at the housing to see if there are screws, a panel, or a small door. Check your owner's manual for your car's specific design. If you still cannot figure it out, a mechanic can do it in five minutes.

Is it safe to drive with a brake light out?

No. A brake light tells drivers behind you that you are slowing down. Without it, you are at much higher risk of being rear-ended. Most places have laws requiring all brake lights to work, and you can be cited for a broken one.