Studebaker 8E14 Brake Light Switch: A Guide for the 1963-1964 Models
Understanding the hydraulic brake light switch in your classic Studebaker truck and how to replace it.
- The 8E14 uses a hydraulic pressure switch, not a modern mechanical one.
- Do not use silicone (DOT 5) brake fluid with this type of switch, as it can cause premature failure.
- Replacement is simple, but requires bleeding the brakes, which is a critical safety step.
- For improved reliability, some owners convert to a mechanical switch mounted by the brake pedal.
Symptoms of a Failing Brake Light Switch
For a straightforward truck like the 8E14, the signs of a bad brake light switch are usually very clear. Before replacing the switch, always check your brake light bulbs and the fuse to rule out simpler problems.
- Brake Lights Do Not Turn On: This is the most common and dangerous symptom. It usually means the internal parts of the switch have failed and can no longer complete the electrical circuit.
- Brake Lights Stay On: If the switch fails in the 'on' position, it will constantly send power to the brake lights, even when you are not braking. This can confuse other drivers and will drain your battery when the truck is parked.
- Intermittent or Flickering Lights: The lights may flicker or only work when you press the brake pedal very hard. This indicates the switch is worn out and unreliable.
Choosing the Right Aftermarket Part
For a 1963-1964 vehicle, finding New Old Stock (NOS) OEM parts can be difficult. Aftermarket parts are the most common and reliable choice for this repair.
Brand Tiers: Standard Ignition
Standard Motor Products (Standard Ignition) is a well-known aftermarket manufacturer that produces the SLS27, a direct replacement for your truck. This is a standard replacement-grade part that meets original specifications. While readily available and affordable, it's important to know that all hydraulic pressure switches of this vintage design can be sensitive. Forum discussions among classic car owners show that these types of switches can sometimes have a limited service life.
Warning: Do Not Use With Silicone Brake Fluid
The original style hydraulic switches, including aftermarket replacements, are often not compatible with silicone-based brake fluids (DOT 5). Using silicone fluid can cause the switch to fail prematurely. If your truck uses silicone fluid, you may need to consider converting to a mechanical switch.
A Note on Reliability: Mechanical Switch Conversion
Some Studebaker owners who have had repeated issues with leaking or failing hydraulic switches choose to convert to a modern mechanical switch. This type of switch is mounted near the brake pedal arm and is activated by the pedal's movement, not by fluid pressure. This is a more reliable, long-term solution, but it does require custom installation and wiring.
Estimated Replacement Costs
The brake light switch itself is an inexpensive part. Labor costs will make up most of the expense if you have a shop perform the work, as the process requires bleeding the brakes.
| Part Type | Price Range |
|---|---|
| New Aftermarket (Standard Ignition) | $15 - $16 |
| New Old Stock (NOS) OEM | $15 - $35 (if found) |
| Shop Labor | $100 - $175 |
Frequently Asked Questions (FAQ)
Where is the brake light switch located on my Studebaker 8E14?
The brake light switch is not inside the cab by the pedal. It is a pressure switch located under the hood, screwed directly into the master cylinder or a nearby brake line junction block. It will have two wires connected to it.
Can I replace the brake light switch myself?
Yes, this is a feasible DIY job for someone comfortable working on brake systems. The switch itself simply unscrews. However, replacing it will introduce air into the brake lines, so you must bleed the brakes afterward to ensure they work safely. If you are not experienced with bleeding brakes, this job is best left to a professional mechanic.
Why do my new aftermarket switches keep failing?
If you experience repeated failures, check what type of brake fluid you are using. As mentioned, silicone (DOT 5) brake fluid is known to cause these hydraulic switches to fail. Sticking with standard DOT 3 or DOT 4 fluid is recommended. If failures persist, converting to a mechanical pedal-activated switch is a popular and more durable solution.
My new switch is installed, but the lights still don't work. What now?
First, re-check the simple things: are the bulbs good and is the fuse intact? Next, use a test light to confirm you have power on one terminal of the switch with the key on. Then, have a helper press the brakes and check for power on the other terminal. If there is power in and out of the switch, the problem lies in the wiring or sockets between the switch and the tail lights. One review noted the terminal pins on a replacement switch were small, so ensure your wire connectors are making a tight connection.
Technical Specifications
OEM Part Numbers: 666858
Switch Type: Hydraulic Pressure Activated Terminal Type: 2-Terminal, Bullet or Screw-In Thread Size: 1/8" - 27 NPT
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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.