Brake Light Switch Guide for the 1952-1956 Mercury Custom
Understanding the simple but critical brake light switch in your classic Mercury.
- The brake light switch is usually a hydraulic type located on the master cylinder, not by the pedal.
- Testing the switch is simple by jumping the two wires at the connector; if lights turn on, the switch is bad.
- Aftermarket switches are the standard; brands like Standard Ignition and Rostra are reliable choices.
- Replacement is an easy DIY job, but be prepared to swap the new switch in quickly to minimize fluid loss.
Identifying Your Brake Light Switch Type
For most 1952-1956 Mercury Customs, the brake light switch is a hydraulic pressure switch. You will not find it attached to the brake pedal under the dash. Instead, look under the hood. The switch is a small, typically brass-colored sensor screwed directly into the master cylinder or a nearby brake line fitting, with two electrical terminals. It is important to confirm this is the type your car has before ordering a part. While less common for this era, some cars may have been converted to a mechanical switch by a previous owner.
A Note on Aftermarket Hydraulic Switches
Owners of classic cars from this era frequently report that modern aftermarket hydraulic brake light switches can have a highly variable service life. Some may fail prematurely. This is a known issue in the classic car community. While some owners with repeated failures opt for a custom conversion to a more reliable mechanical switch 🎬 Watch this guide on installing a mechanical brake light switch., a direct-fit hydraulic switch remains the simplest repair.
Choosing the Right Aftermarket Brake Light Switch
For a vehicle of this age, new Original Equipment Manufacturer (OEM) parts from Mercury are no longer produced. Aftermarket parts are the standard for repairs. The quality of these simple switches is generally good, but brand reputation can be a factor.
- Standard Ignition (Standard Motor Products): A very well-established brand with over 100 years in the business, Standard is a trusted name for electrical components in the professional repair community. Their switches are known for quality materials, such as copper alloy conductors, and are 100% tested. They are often considered a reliable, premium aftermarket choice.
- Rostra Powertrain: Rostra is another major manufacturer of aftermarket and OE components, particularly known for transmission electronics and sensors. They produce a wide range of switches engineered to meet or exceed original specifications and are also a viable and reliable choice for your Mercury.
Pro Tip: When replacing a hydraulic switch, have the new switch ready to go. Unscrew the old one and quickly screw in the new one to minimize brake fluid loss. You may need to top off the master cylinder, but this can often prevent the need to bleed the brakes.
Cost of a New Brake Light Switch (1952-1956 Mercury Custom)
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket (Rostra, Standard) | $10.92 - $15.52 |
| New OEM (Ford/Mercury) | N/A (Discontinued) |
| Shop Labor for Installation | $50 - $120 |
Frequently Asked Questions (FAQ)
How do I test my Mercury's brake light switch?
First, ensure your brake light bulbs are good. Then, locate the hydraulic switch on the master cylinder. Unplug the two wires connected to it. Use a small jumper wire to carefully connect the two wire terminals together. If the brake lights illuminate, the switch is faulty and needs replacement. If they do not light up, the problem is elsewhere in the wiring, such as a fuse or a bad ground.
Could something else cause my brake lights to fail?
Yes. On these cars, the power for the brake lights often runs through the turn signal switch. A faulty turn signal switch can sometimes interrupt the brake light circuit. Also, check for blown fuses (if applicable to your specific model's wiring) and ensure all ground connections are clean and tight.
Are there any recalls for the brake light switch on my Mercury Custom?
No. There are no recalls on file with the National Highway Traffic Safety Administration (NHTSA) for the brake light switch on 1952-1956 Mercury vehicles. Digital records for vehicles of this age are extremely rare.
Do I need to bleed the brakes after replacing the switch?
If you are quick about swapping the old hydraulic switch for the new one, you can often avoid introducing enough air into the system to require a full brake bleed. However, it is a possibility. After installation, the brake pedal should feel firm. If it feels spongy, you have air in the lines and the brakes must be bled before driving.
Helpful Videos
Technical Specifications
OEM Part Numbers: 11A-13480 B2A-13480-A 0A-13480
Hydraulic Pressure Activated, Thread Size: 1/8 in. NPT
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.