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1963-1964 Studebaker 8E15 Brake Light Switch: An Owner's Guide

Everything you need to know about replacing the hydraulic brake light switch on your classic Studebaker truck.

4 minutes to read 1963-1964 Studebaker 8E15
Difficulty
1/5
Est. Time
0.5 hrs
DIY Doable?
✅ Yes
Shop Labor
$50-$100
🚫 Do not drive — Driving without working brake lights is illegal and extremely dangerous; the vehicle should be repaired immediately.
Key Takeaways
  • The 1963-64 Studebaker 8E15 uses a hydraulic pressure switch, not a mechanical pedal switch.
  • Do NOT use this aftermarket switch with silicone (DOT 5) brake fluid, as it can cause rapid failure.
  • Failure is critical, as it means your brake lights will not work. Do not drive the vehicle until it is fixed.
  • Replacement is a simple DIY task for most owners, located on the master cylinder or a brake line block.
The brake light switch on your 1963-1964 Studebaker 8E15 is a vital safety component. Unlike modern vehicles, your truck uses a hydraulic pressure switch, not a mechanical one at the pedal. This switch is typically screwed into the master cylinder or a brake line junction block. When you press the brake pedal, the pressure of the brake fluid increases. This pressure activates the switch, which completes an electrical circuit and turns on your brake lights. A functioning switch is essential for signaling your intentions to other drivers.

Symptoms of a Failing Brake Light Switch

On a classic truck like the Studebaker 8E15, diagnosing a bad brake light switch is usually straightforward. Before you replace the switch, always check the brake light bulbs and the fuse first. If those are good, the switch is the next likely problem.

  • Brake Lights Do Not Work: This is the most common and dangerous symptom. If the bulbs and fuse are fine, the switch has likely failed internally and isn't completing the circuit.
  • Brake Lights Stay On: The switch can fail in the 'on' position, causing the brake lights to remain lit even when you're not braking. This will drain your battery and confuse other drivers.
  • Flickering Brake Lights: An intermittent connection inside a worn-out switch can cause the lights to flicker or work only some of the time.

Choosing the Right Aftermarket Switch

Since original Studebaker-branded parts are no longer in production, you will be choosing an aftermarket part. For the 1963-1964 8E15, the primary replacement option is from established brands like Standard Ignition.

Brand Quality: Standard Ignition

Standard Ignition (also known as Standard Motor Products or SMP) is a well-regarded aftermarket manufacturer. Their replacement switches are designed to meet original equipment specifications for fit and function. They typically use quality components like copper alloy conductors and durable housings to ensure reliability and a long service life. For many classic vehicle owners, Standard is a trusted source for electrical components.

Warning: Do Not Use With Silicone Brake Fluid

The most critical issue with these hydraulic switches is their incompatibility with silicone (DOT 5) brake fluid. Many classic car owners use DOT 5 fluid because it doesn't harm paint, but it is known to cause premature failure in reproduction hydraulic switches. The Standard Ignition switch specifically warns against use with silicone brake fluid. If you use DOT 5 fluid, you may experience repeated switch failures. For this reason, some owners modify their trucks to use a more modern mechanical switch at the brake pedal.

Brake Light Switch Replacement Cost

Replacing the brake light switch is one of the more affordable repairs for your Studebaker truck. The part itself is inexpensive, and labor is minimal due to its easy accessibility.

Part Type Part Cost Estimated Labor Cost Total Estimated Cost
New Aftermarket (Standard Ignition) $15.52 $50 - $100 $65 - $115
New Old Stock (OEM) Varies, often $50+ $50 - $100 $100+

Cost estimates are for reference only and may vary based on your location and the specific repair shop.

Pro Tip: Testing Your Old Switch

You can easily test your existing switch. First, locate it on the master cylinder or frame. Unplug the two wires connected to it. Then, use a small jumper wire to connect the two wire terminals together. If your brake lights turn on, the switch is faulty and needs to be replaced. If they do not light up, the problem lies elsewhere in the wiring or fuse circuit.

Frequently Asked Questions (FAQ)

Can I drive my Studebaker with a bad brake light switch?

No. Driving without functional brake lights is illegal and extremely dangerous. You risk a traffic ticket and, more importantly, a rear-end collision. This repair should be made immediately.

Is replacing the brake light switch a DIY job?

Yes, for most owners this is a very simple DIY task. It requires basic hand tools to unscrew the old switch and screw in the new one. You may need to bleed the brakes afterward if any air enters the system, but often the switch can be swapped quickly to minimize fluid loss.

Where is the brake light switch located on my 1963-1964 Studebaker 8E15?

It is not inside the cab. Look for a small, two-terminal switch screwed directly into the brake master cylinder or into a junction block on the frame where brake lines meet.

What is the difference between a hydraulic and a mechanical switch?

Your Studebaker uses a hydraulic switch that is activated by brake fluid pressure. Most modern cars use a mechanical switch that is activated by the physical movement of the brake pedal arm. Due to reliability issues with reproduction hydraulic switches, especially with silicone fluid, some owners fabricate a bracket to install a more reliable mechanical switch.

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

No, there are no active recalls or Technical Service Bulletins (TSBs) from the NHTSA for this part on a 1963-1964 Studebaker 8E15.

Technical Specifications

OEM Part Numbers: 666858

Hydraulic Pressure Activated, 2-Terminal, 1/8-27 NPT Thread

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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.

Year Coverage
This article covers the Brake Light Switch for:
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