Guide to the 1963-1964 Studebaker 8E7D Brake Light Switch
Understanding the unique hydraulic brake light switch in your classic Studebaker truck and how to replace it correctly.
- The 1963-64 Studebaker 8E7D uses a hydraulic pressure switch in the brake line, not a mechanical switch at the pedal.
- Aftermarket hydraulic switches are known to fail when used with silicone brake fluid; use standard DOT 3 or 4 fluid.
- Replacing the switch is simple, but you MUST bleed the brakes afterward to remove air from the system.
- A new aftermarket switch from a brand like Standard Ignition is a reliable and cost-effective choice.
Is Your Studebaker's Brake Light Switch Failing?
On a classic truck like the 8E7D, you won't get a warning light on the dashboard for a faulty brake light switch. Diagnosis is straightforward and relies on a visual check. Before suspecting the switch, always check the brake light bulbs and the fuse first, as these are simpler fixes.
Key Failure Symptoms
- Brake Lights Do Not Turn On: This is the most common and dangerous symptom. If the bulbs and fuse are good, the switch has likely failed internally and is not completing the electrical circuit.
- Brake Lights Stay On: The switch can fail in the 'on' position, causing the brake lights to remain lit even when the pedal is not pressed. This will drain your battery and confuse other drivers.
- Lights Only Work Under Hard Braking: A failing switch may require more hydraulic pressure than usual to activate, meaning your lights only come on during heavy braking, which is unsafe.
Choosing the Right Aftermarket Switch
For a vehicle from the early 1960s, finding a New Old Stock (NOS) Studebaker part is difficult and often expensive. The materials in a 60-year-old switch may also be degraded. A new aftermarket part is the most practical and reliable choice.
Standard Ignition Switches
Standard Ignition (a brand of Standard Motor Products) is a well-known manufacturer that produces replacement parts for classic vehicles. Their switches are made with quality materials like copper alloy conductors and are tested to ensure performance. For a simple but crucial part like a hydraulic brake switch, a new component from a reputable brand like Standard is a dependable option.
Warning: Do Not Use With Silicone Brake Fluid
The original style hydraulic pressure switches are known to fail prematurely when used with silicone brake fluid. Studebaker parts catalogs specifically note that the replacement part (OEM #666858) is not for use with silicone fluid. If you have converted your truck to silicone fluid, you may experience repeated switch failures. The common solution for this is to modify the truck to use a mechanical switch at the brake pedal, though this requires custom work.
Typical Replacement Costs
The cost to replace the brake light switch is low for the part itself, with labor being the main variable. The key factor is that the brake system must be bled after replacement.
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket (Standard Ignition) | $15.52 |
| New Old Stock (OEM) | Rare, cost varies greatly |
| Shop Labor (including brake bleeding) | $100 - $200 |
Pro Tip: Test Before You Replace
You can easily test the switch. First, locate it on the master cylinder or frame rail. Unplug the two wires connected to it. Then, use a small jumper wire to connect the two wire terminals together. If the 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 panel.
Frequently Asked Questions (FAQ)
Where is the brake light switch located on my 1963-1964 Studebaker truck?
It is not inside the cab by the pedal. It is a hydraulic pressure switch located under the hood, screwed into the master cylinder or a brake line junction block on the driver's side frame rail. It will have two electrical wires connected to it.
Do I need to bleed the brakes after replacing the switch?
Yes. Because the switch is part of the hydraulic brake line system, removing it will introduce air into the lines. You must bleed the brakes after installing the new switch to ensure your brakes function safely. Failure to do so can result in a soft or non-functional brake pedal.
Are there any recalls for the brake light switch on a Studebaker 8E7D?
No recalls or Technical Service Bulletins (TSBs) from the NHTSA were found related to the brake light switch for this vehicle. This is common for vehicles of this era.
Why do my new switches keep failing?
The most common reason for repeated failure of these hydraulic switches in classic cars is the use of silicone brake fluid. If you are using silicone fluid, consider converting to a mechanical-style switch that mounts near the brake pedal arm.
Technical Specifications
OEM Part Numbers: 666858
Hydraulic Pressure Activated, 2-Terminal
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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.