1956 Studebaker Power Hawk Brake Light Switch Guide
Understanding the hydraulic pressure switch in your classic Studebaker and how to choose the right replacement.
- The 1956 Power Hawk uses a hydraulic pressure switch on the master cylinder, not a mechanical one at the pedal.
- Aftermarket reproduction switches are not compatible with DOT 5 silicone brake fluid; use DOT 3 fluid to prevent premature failure.
- A failing switch is a critical safety issue that can cause your brake lights to not work at all or stay on constantly.
- Replacement is a simple DIY task, but bleeding the brakes afterward is mandatory for safety.
Understanding the 1956 Power Hawk's Hydraulic Switch
If your brake lights have stopped working, the brake light switch is a common suspect. On the 1956 Power Hawk, the switch is a pressure-activated unit located on the master cylinder under the hood. This design was common for the era but has known reliability issues. Original-style hydraulic switches are known to fail, sometimes requiring significant pedal pressure to activate, which means your lights may not turn on during gentle stops. They are also a potential source of brake fluid leaks.
A Critical Note on Brake Fluid
Many classic car owners upgrade to DOT 5 silicone brake fluid. However, most reproduction hydraulic brake light switches are not compatible with silicone fluid and are designed for standard DOT 3 fluid. Using silicone fluid can cause a new switch to fail very quickly. Always check the part's specifications. If you use silicone fluid, converting to a mechanical switch is a more reliable option.
Symptoms of a Failing Brake Light Switch
- Brake Lights Don't Work: The most common and dangerous symptom. The switch fails to complete the circuit, leaving you without brake lights.
- Brake Lights Stay On: The switch can fail in the 'on' position, leaving the brake lights constantly illuminated and draining your battery.
- Intermittent Operation: The lights may flicker or only work when the pedal is pressed very hard. This is a sign of impending failure.
- Brake Fluid Leak: A leak from the switch itself indicates a failure of its internal seals.
Choosing an Aftermarket Replacement
For a vehicle of this age, finding a "New Old Stock" (NOS) OEM part is rare, and its rubber seals may be brittle. The most practical solution is a new aftermarket reproduction. Standard Ignition is a well-regarded brand that manufactures a direct-fit replacement hydraulic switch for this application. It is designed to match the original specifications for fit and function.
Considering a Mechanical Switch Upgrade
For improved reliability, many Studebaker owners convert to a modern mechanical brake light switch. This type of switch is mounted near the brake pedal and is activated by the pedal's movement, not hydraulic pressure. This eliminates the fluid compatibility issue and the potential for leaks. While this is a more involved installation that requires some custom fabrication, it is a popular and durable long-term solution.
| Part Type | Estimated Cost | Notes |
|---|---|---|
| New Aftermarket (Hydraulic) | $15 - $20 | Most common and affordable option. Standard Ignition is a known brand. |
| New Old Stock (NOS) OEM | $50 - $100+ | Very rare to find. Seals may be aged and unreliable. |
| Used OEM | $10 - $25 | Not recommended due to age and high failure rate of original switches. |
| Mechanical Switch Upgrade | $20 - $40 | Requires a universal switch and custom installation. More reliable long-term. |
Frequently Asked Questions
Where is the brake light switch located on my 1956 Power Hawk?
It is not inside the car by the pedal. It is a hydraulic pressure switch screwed into the master cylinder, which is located under the hood. It will have two electrical wires connected to it.
Is it difficult to replace the brake light switch myself?
For a DIY mechanic, this is a relatively easy job. It involves unplugging the wires, unscrewing the old switch, and quickly screwing in the new one to minimize fluid loss. However, you must bleed the brakes after replacement to remove any air that entered the system, which is critical for safety.
Are there any recalls for the 1956 Power Hawk brake light switch?
There are no specific NHTSA recalls or Technical Service Bulletins (TSBs) for the brake light switch on the 1956 Studebaker Power Hawk. This is common for vehicles of this vintage.
Why do my new switches keep failing?
The most common reason for repeat failures is using DOT 5 silicone brake fluid with a switch that is not designed for it. The chemical properties of silicone fluid can damage the internal diaphragm of incompatible switches. Stick with DOT 3 fluid if using a standard reproduction switch.
Technical Specifications
OEM Part Numbers: 666858
Type: Hydraulic Pressure Switch, Location: Master Cylinder, Activation: Brake Fluid Pressure
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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.