How to Replace the Brake Light On a 2005 to 2009 Ford Mustang

2006 Ford Mustang GT
Car Culture, Inc. / Getty Images

Sooner or later you’re going to have to replace a brake light on your Ford Mustang. How do you know when it’s time to complete this task? Well, a telltale sign is a turn signal that chimes faster than usual when you make a turn. If this happens when you put your left turn signal on, a bulb on the left side of the vehicle has likely gone out. Either that or it’s loose. If it happens when you use the right turn signal, it’s likely a bulb on the right side of the vehicle.

Years ago, replacing a bulb was pretty simple. Owners of 2005 to 2009 Mustangs will find this task is a bit more involved than in the days of old. In order to replace a taillight, you will have to remove some trim in your trunk, as well as a few retaining screws. The entire tail light assembly will then need to be carefully removed so you can gain access to the bulb sockets in the rear.

What follows is a step-by-step replacement of a brake light on a 2008 Ford Mustang. For information regarding other model years, please consult your owner's manual or contact your local Ford Dealer.

Fix a Ford Mustang Brake Light

To do this, you'll need the following:

  • Small Flathead Screwdriver
  • 1/4-inch Drive 7/16 or 11mm Socket and Ratchet
  • Sylvania 4057 or 4057LL Replacement Bulb

Time Required: 15 minutes

01
of 14

Brake Light Not Working

Brake light not working
Brake light not working. Photo © Jonathan P. Lamas

As you can see, one of the two brake light bulbs on this Mustang (the one in the center) is not working properly.

02
of 14

Clean out the Trunk

Clean out the Trunk
Clean out the Trunk. Photo © Jonathan P. Lamas

Make sure your trunk is free of any cargo.

03
of 14

Remove Trim Screw

Remove Trim Screw
Remove Trim Screw. Photo © Jonathan P. Lamas

Remove the plastic screws from the left and right side trunk trim.

04
of 14

Remove the Center Pin Lock Retainers

Remove the Center Pin Lock Retainers
Remove the Center Pin Lock Retainers. Photo © Jonathan P. Lamas

Remove the four center pin lock retainers from the trim panel. Using a flathead screwdriver or your finger, lift up the center of the pin. You can then remove the rest of the pin.

*Caution: Take care not to use too much force as not to break the retainers.

05
of 14

Remove the Plastic Trunk Trim Piece

Remove the Plastic Trunk Trim Piece
Remove the Plastic Trunk Trim Piece. Photo © Jonathan P. Lamas

Now that the trim screws and center pin lock retainers have been removed, you can carefully remove the plastic trunk trim piece by lifting it upward and out of the trunk.

06
of 14

Remove the Nuts

Remove the Nuts
Remove the Nuts. Photo © Jonathan P. Lamas

Now it’s time to remove the three 11mm nuts on the back of the light. Because we are replacing the brake light on the right side of the vehicle, we’ll focus on the right light.

Tip: Make sure to keep track of each nut and pin so they don’t get lost.

07
of 14

Put Down Protective Cloth

Put Down Protective Cloth
Put Down Protective Cloth. Photo © Jonathan P. Lamas

After removing the nuts, tilt the light assembly forward so you can access the bulb compartments. Before doing so, make sure to put a protective cloth beneath the assembly so you do not scratch your Mustang’s bumper.

08
of 14

Remove the Old Light

Remove the Old Light
Remove the Old Light. Photo © Jonathan P. Lamas

Because you previously noted which light had burnt out, you can now remove that light by tilting the entire taillight assembly forward and twisting the old bulb out of its socket.

09
of 14

Replace with New Light

Replace with New Light
Replace with New Light. Photo © Jonathan P. Lamas

Now you can replace the burnt out bulb with a new bulb. Although Ford recommends using Sylvania 4057 or 4057LL, several people have reported success when using the Sylvania 3157LL bulb, which happens to be more readily accessible at local retail stores. As always, consult your owner’s manual or local Ford dealer for advice regarding the correct part.

10
of 14

Test New Light

Test New Light
Test New Light. Photo © Jonathan P. Lamas

Before you put everything back together, you want to make sure the new bulb is functioning properly. As you can see here, both brake lights function. Problem solved. Now it’s time to start putting everything back together again.

11
of 14

Reposition Taillight Assembly

Now that you’ve tested to make sure the new bulb functions properly, carefully place it back into its correct position. Make sure it is seated snug and tight. Then replace the three nuts at the rear of the assembly, making sure not to drop the taillight in the process.

12
of 14

Replace Trunk Trim

Replace Trunk Trim
Replace Trunk Trim. Photo © Jonathan P. Lamas

With all three nuts snug and tight, now carefully replace the trunk trim within the trunk of the Mustang.

13
of 14

Replace Center Pin Lock Retainers

Replace Center Pin Lock Retainers
Replace Center Pin Lock Retainers. Photo © Jonathan P. Lamas

Replace the four center pin lock retainers by pushing them firmly into position.

14
of 14

Replace the Trim Screws

Replace the Trim Screws
Replace the Trim Screws. Photo © Jonathan P. Lamas

Now replace the two trim screws by turning them to the right. After they are in place, double check to make sure the trunk trim is tight and in the correct position. If so, you have now successfully replaced your brake light. Congratulations!

*If you notice a loose nut or piece of trim that is out of place, go back through the steps to make sure everything is tight and in place.