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Studebaker 3E13 Brake Light Switch: Replacement and Diagnosis Guide (1958)

Keep your classic 1958 Studebaker 3E13 safe and on the road by understanding its simple but vital brake light switch.

3 minutes to read 1958-1958 Studebaker 3E13
Difficulty
1/5
Est. Time
0.5 hrs
DIY Doable?
✅ Yes
Shop Labor
$50-$100
🚫 Do not drive — Driving without functional brake lights is illegal and extremely dangerous for you and other drivers.
Key Takeaways
  • A faulty brake light switch is a critical safety issue that must be fixed immediately.
  • The 1958 Studebaker 3E13 uses a hydraulic pressure switch, not a mechanical one at the pedal.
  • Always check the bulbs and fuse before assuming the switch has failed.
  • A new aftermarket switch from a brand like Standard Ignition is the most reliable and practical replacement option.
On your 1958 Studebaker 3E13, the brake light switch is a hydraulic pressure switch. Unlike modern cars that use a mechanical switch on the brake pedal, your truck uses the pressure from the brake fluid itself to activate the switch. When you press the brake pedal, the building hydraulic pressure closes an electrical circuit inside the switch. This sends power to the rear brake lights, letting other drivers know you are slowing down or stopping. It's a simple and effective design used on most American vehicles from the 1930s to the 1960s.

Is Your Studebaker's Brake Light Switch Failing?

A bad brake light switch on a classic truck like the 1958 Studebaker 3E13 creates an immediate safety hazard. Since there are no complex electronics or dashboard warning lights for this system, you'll only know there's a problem by physically checking the lights or if someone points it out to you. The symptoms are usually very clear.

Safety First: Check Bulbs and Fuses

Before you decide the switch is bad, always check the simple things first. Make sure your brake light bulbs haven't burned out and that the fuse for the circuit is good. This can save you time and prevent you from replacing a perfectly good part.

Choosing the Right Aftermarket Switch

For a vehicle made in 1958, finding a "new" original equipment (OEM) part from Studebaker is not a realistic option. Your main choices are New Old Stock (NOS), used original parts, or new aftermarket parts.

  • New Old Stock (NOS): These are original parts that were never installed. They are very rare, expensive, and can sometimes degrade after decades in storage. They are mostly for collectors aiming for 100% originality.
  • Used OEM: These are parts taken from other classic trucks. Their condition and remaining lifespan are unknown, making them a gamble.
  • New Aftermarket: This is the most practical and common choice. Brands like Standard Ignition produce new replacement switches designed to meet or exceed the original specifications. For a simple component like a hydraulic brake light switch, a modern aftermarket part is often more reliable and durable than an original from the 1950s.
Brake Light Switch Cost Comparison: 1958 Studebaker 3E13
Part Type Estimated Cost Notes
New Aftermarket (Standard Ignition) $15 - $20 Readily available, reliable, and the most common choice.
New Old Stock (NOS) $35+ Very difficult to find. Primarily for collectors.
Used OEM Varies Available from classic car salvage yards; condition is not guaranteed.
Shop Labor $50 - $100 Installation is simple, but labor rates vary.

Frequently Asked Questions

Is it difficult to replace the brake light switch myself?

No, this is a very easy job for most DIY mechanics. The hydraulic switch is typically screwed into the master cylinder or a brake line junction block. You will need basic hand tools to unscrew the old switch and install the new one. The entire job can usually be done in under 30 minutes.

Where is the brake light switch located on my 1958 Studebaker 3E13?

The brake light switch is a hydraulic switch, not a mechanical one at the pedal. Look for it mounted directly on the brake master cylinder or on a nearby brake line junction block under the hood or along the frame rail. It will have two electrical wires connected to it.

Do I need to bleed my brakes after replacing the switch?

It's possible. When you unscrew the old switch, a small amount of brake fluid will leak out. To minimize fluid loss and air entry, have the new switch ready to install immediately. If too much air enters the system, you will need to bleed the brakes to ensure proper braking function.

Are aftermarket switches as good as the original for this truck?

Yes. For a simple part like a hydraulic brake light switch, modern manufacturing standards often result in a part that is more durable and consistent than what was available in the 1950s. Reputable aftermarket brands like Standard Ignition are a dependable choice.

Could silicone brake fluid cause the new switch to fail?

While this is a topic of debate in the classic car community, some sources note that certain replacement switches may not be compatible with silicone brake fluid. However, other experts state that switch failure is due to poor internal contacts, not the type of fluid used. If you use standard DOT 3 or DOT 4 fluid, this is not a concern. If you have converted to silicone fluid, be aware of this potential issue.

Technical Specifications

OEM Part Numbers: 666858

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

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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