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Guide to the 1958 Studebaker 3E1 Brake Light Switch

Keep your classic Studebaker truck safe and reliable by understanding how to diagnose and replace a faulty brake light switch.

3 minutes to read 1958-1958 Studebaker 3E1
Difficulty
2/5
Est. Time
1 hrs
DIY Doable?
✅ Yes
Shop Labor
$90-$150
Used OEM Price
$10-$30
🚫 Do not drive — Driving without functional brake lights is illegal and extremely dangerous for you and other drivers.
Key Takeaways
  • A failing brake light switch on your 3E1 is a critical safety hazard and must be addressed immediately.
  • The switch is a hydraulic pressure type, located on the master cylinder or a brake line block, not at the pedal.
  • New aftermarket switches from a quality brand like Standard Ignition are the most reliable and affordable replacement option.
  • Replacement is a simple DIY job, but you must be prepared to bleed the brakes afterward to ensure they are safe.
On your 1958 Studebaker 3E1, the brake light switch is a critical safety part. Unlike modern vehicles that often use a mechanical switch at the pedal, your truck uses a hydraulic pressure switch. This switch is typically screwed into the master cylinder or a brake line junction block. When you press the brake pedal, the hydraulic fluid pressure builds up and activates the switch. This completes an electrical circuit, sending power to the brake lights to warn other drivers you are slowing down.

Is Your Studebaker's Brake Light Switch Failing?

A bad brake light switch on a classic truck like the 1958 3E1 is a serious safety problem. The signs of failure are usually clear because the system is simple. Before you decide the switch is bad, always check the bulbs and the fuse first. These are easier and cheaper to fix.

Key Failure Symptoms

  • Brake Lights Don't Turn On: This is the most dangerous symptom. If the bulbs and fuse are good, the switch has likely failed and can no longer complete the electrical circuit.
  • Brake Lights Stay On: The switch can get stuck in the 'on' position. This will drain your battery when parked and can confuse drivers behind you.
  • Flickering or Intermittent Lights: If the lights flicker when you press the pedal or hit a bump, the switch is worn out and can't be trusted.

Pro Tip: How to Test Your Switch

You can easily test the switch. First, find it on the master cylinder or a nearby brake line junction. Unplug the two wires connected to it. Use a small piece of wire (a jumper wire) to connect the two unplugged wire terminals together. If the brake lights turn on, the switch is bad. If they don't, the problem is somewhere else in the wiring.

Choosing the Right Replacement Switch

For a vehicle from 1958, you cannot buy a new brake light switch from Studebaker. Your options are a new aftermarket part or a New Old Stock (NOS) part.

  • New Old Stock (NOS): These are original, unused parts from decades ago. They are very rare, can be expensive, and may have degraded over time.
  • New Aftermarket: This is the most common and practical choice. Brands like Standard Ignition (also known as Standard Motor Products or SMP) produce reliable, direct-fit replacement switches. These parts are affordable, readily available, and manufactured to modern standards.

A Note on Brake Fluid

Some aftermarket hydraulic switches are not designed for use with DOT 5 silicone brake fluid. Using the wrong fluid can make the new switch fail quickly. The Standard Ignition switch is made to work with standard DOT 3 brake fluid, which was original for your truck.

Cost of Replacing a 1958 Studebaker 3E1 Brake Light Switch

Part Type Estimated Cost
New Aftermarket (Standard Ignition) $15.52 - $15.52
New Old Stock (OEM) Varies widely, often $40+
Shop Labor $90 - $150

Frequently Asked Questions (FAQ)

Where is the brake light switch located on a 1958 Studebaker 3E1?

The brake light switch is a hydraulic pressure switch located under the hood, not inside the cab. It is screwed directly into the master cylinder or a brake line junction block on the frame. It will have two wires attached to it.

Can I replace the brake light switch myself?

Yes, this is a straightforward job for a DIYer. You will need basic hand tools to unscrew the old switch. To minimize brake fluid loss, have the new switch ready to screw in as soon as you remove the old one. You may need to top off the brake fluid and bleed the brakes if air gets into the system.

Is an aftermarket switch as good as the original?

Yes. For a simple component like a brake light switch, modern manufacturing often results in a more reliable part than what was available in the 1950s. Reputable brands like Standard Ignition are a trusted choice for classic vehicles.

Are there any recalls for the brake light switch on my Studebaker?

No, searches of the National Highway Traffic Safety Administration (NHTSA) database show no recalls for the brake light switch on 1958 Studebaker trucks. Recalls were not as common or as well-documented for vehicles of this era.

Technical Specifications

OEM Part Numbers: 666858

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

Wrenchy
Article researched & written by
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Meet Wrenchy → Updated Jul 21, 2026

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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