The back brake light on a 2013 Subaru Legacy is typically fixed by replacing the bulb inside the tail-light housing. It’s a straightforward DIY job that usually requires only a replacement bulb and a few common hand tools. If the housing is cracked or water-damaged, you may need to replace the entire tail-light unit.
What you’ll need
Before you begin, gather the essential items. This ensures a smooth, safe replacement and helps you avoid repeated trips to the store.
- Replacement bulb(s) of the correct type (see below for how to identify the exact bulb).
- Owner’s manual or bulb reference for the exact specification (commonly 7443 or equivalent for Subaru Legacy rear brake/taillights).
- Gloves or a clean cloth to handle bulbs (to avoid oils from your skin on the glass).
- Basic hand tools: flat-head screwdriver or plastic pry tool, and a socket wrench or screwdriver (often 8–10 mm or Phillips head depending on trim).
- Optional: a flashlight, torque wrench, and a replacement tail-light gasket/seal if you’re replacing the whole unit.
With these items on hand, you’re ready to begin the replacement process.
Step-by-step bulb replacement
Follow these steps in order to remove the old bulb and install a new one without damaging the tail light or the car’s electrical system.
- Park on a level surface, turn off the engine, and open the trunk. Remove the trunk-side plastic trim panel or carpeting to access the tail-light housing.
- Locate and remove the screws or bolts securing the tail-light assembly to the body. These are usually 2–3 and may be accessible from inside the trunk or from the wheel well area, depending on trim.
- Gently pull the tail-light assembly away from the body, being careful not to damage the wiring harness.
- Detach the wiring harness by unplugging the connector from the back of the tail-light. Press the retaining tab and pull to disconnect.
- Twist or remove the bulb socket counterclockwise (or as indicated by the housing) and pull the bulb out of the socket.
- Insert a new bulb of the correct type into the socket, then reinsert the socket into the housing and twist to lock.
- Reconnect the wiring harness to the back of the tail-light, position the tail-light back into the body, and secure it with the screws/bolts you removed earlier.
- Reattach the trunk panel or carpeting and close the trunk. Test the brake light by pressing the brake pedal and verifying the light illuminates as expected. If available, also test the tail and turn signals to ensure all functions remain correct.
- If lighting problems persist, recheck bulb seating, wiring, and fuses, or consult a professional technician.
Replacement is complete when the brake light functions consistently and the tail-light seal remains intact to prevent water intrusion.
Tips, troubleshooting, and when to replace the whole unit
Most 2013 Subaru Legacy models use a dual-filament rear brake/taillight bulb; confirming the exact type requires inspecting the bulb or consulting the owner’s manual. If the bulb is fine but the brake signal doesn’t light, check the relevant fuse and the brake light switch. Moisture, a cracked housing, or corrosion may necessitate replacing the entire tail-light assembly rather than just the bulb.
Common bulb types for reference
For many Legacy models, the rear brake/taillight uses a 7443 dual-filament bulb; however, some trims or markets use variants like 7440 or 3157. Do not assume—verify the installed bulb or check the manual.
Electrical checks to consider
If bulb replacement doesn’t fix the issue, inspect fuses, wiring harness connections, and the brake light switch. A multimeter can help identify a short or open circuit.
When to replace the entire tail light assembly
If the lens is cracked, water has entered the housing, or there is cosmetic or electrical damage that cannot be repaired with a bulb change, replacing the whole tail-light unit is advisable. The process is similar but may require a full disassembly and resealing to prevent leaks; consult a professional if you’re unsure.
Summary
Replacing the back brake light on a 2013 Subaru Legacy is typically a bulb swap inside the tail-light housing. Gather the right bulb, a few simple tools, and take care when handling the bulb to avoid skin oils. If the bulb is fine but the light still doesn’t work, check fuses and wiring, and consider whether the entire tail-light assembly needs replacement due to damage or moisture. With careful steps, you can restore proper braking illumination and stay safe on the road.