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Guide to the Brake Light Switch for the 1959 Studebaker 4E3D

Learn about the common failure points of the hydraulic brake light switch on your classic Studebaker truck.

3 minutes to read 1959-1959 Studebaker 4E3D
Difficulty
2/5
Est. Time
0.75 hrs
DIY Doable?
✅ Yes
Shop Labor
$75-$150
Used OEM Price
null
🚫 Do not drive — It is illegal and extremely unsafe to drive a vehicle with non-functioning brake lights.
Key Takeaways
  • The 1959 Studebaker 4E3D uses a hydraulic pressure switch on the master cylinder, not a mechanical switch at the pedal.
  • The most common failure symptom is brake lights that do not work, which is a critical safety hazard.
  • Replacement is simple for a DIYer, but you must bleed the brakes afterward to ensure safety.
  • Standard Ignition is a common and reliable aftermarket brand for this replacement part.
The brake light switch on a 1959 Studebaker 4E3D is a critical safety part. Unlike modern cars that use a mechanical switch at the brake pedal, your truck uses a hydraulic pressure switch. This switch is screwed directly into the brake's master cylinder. When you press the brake pedal, the building pressure of the brake fluid activates the switch. This completes an electrical circuit and turns on your rear brake lights, showing drivers behind you that you are slowing down.

Understanding the Hydraulic Brake Light Switch in Your Studebaker

If the brake lights on your 1959 Studebaker 4E3D stop working, the brake light switch is a common part to fail. On these classic trucks, the switch is not a button located by the pedal. Instead, it is a pressure-activated switch found on the master cylinder in the engine bay. This design was typical for the time but is known to have reliability issues. The original-style hydraulic switches can leak brake fluid or fail internally, which can cause your brake lights to stop working entirely.

Symptoms of a Failing Brake Light Switch

  • Brake Lights Do Not Turn On: The most common and dangerous symptom is when the brake lights do not light up at all when you press the brake pedal. This is a major safety risk.
  • Brake Lights Stay On: The switch can fail in the "on" position, causing the brake lights to stay lit even when your foot is off the pedal. This can drain your battery and confuse other drivers.
  • Intermittent Operation: The lights may flicker or only work sometimes. This can be due to a faulty connection inside the aging switch.

Choosing the Right Aftermarket Switch

Finding a New Old Stock (NOS) OEM Studebaker brake light switch is very difficult. The most practical solution is a new aftermarket part. Standard Ignition is a well-known brand that produces a compatible replacement switch (Part No. SLS27). This brand is widely used in the classic car community and is known for making reliable parts that meet or exceed original specifications. Their switches are designed with quality materials like brass housings and copper conductors to ensure durability and proper electrical performance.

A Note on Upgrades

Some Studebaker owners modify their trucks to use a modern, mechanical brake light switch that mounts near the brake pedal. This is a custom job that eliminates the hydraulic switch, providing more reliable operation and removing a potential leak point. However, for a direct and simple repair, a quality aftermarket hydraulic switch is the easiest choice.

Cost of a New Brake Light Switch (1959 Studebaker 4E3D)

Part Type Estimated Cost
New OEM (NOS) Rare / Not Available
New Aftermarket (Standard Ignition) $15.52
Used OEM Not Recommended
Shop Labor for Installation $75 - $150

Frequently Asked Questions (FAQ)

Where is the brake light switch located on my 1959 Studebaker 4E3D?

The brake light switch is not inside the cab. It is a hydraulic pressure switch screwed into the master cylinder, which is located under the hood in the engine bay. It will have two wires connected to it.

Is it difficult to replace this switch myself?

For a DIY mechanic, this is a fairly easy job. It involves unplugging the wires and unscrewing the old switch. The key step is that you must bleed the brakes after replacing the switch to remove any air that entered the system. If you are not familiar with bleeding brakes, it is best to have a professional do the job.

How do I test my old brake light switch?

First, make sure your brake light bulbs and the fuse are good. If they are, find the switch on the master cylinder. Unplug the two wires and use a small jumper wire to carefully connect them. If the brake lights turn on, the switch is bad and needs to be replaced. If they do not light up, the problem is somewhere else in the wiring.

Are there any recalls for this part?

No, there are no NHTSA recalls or Technical Service Bulletins (TSBs) for the brake light switch on a 1959 Studebaker. This is normal for a vehicle of this age, as the NHTSA database was created much later and does not typically cover vehicles this old.

Technical Specifications

OEM Part Numbers: 666858

Hydraulic pressure activated, 2-terminal, 1/8-27 thread pitch.

Wrenchy
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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.

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