1946-1947 Hudson Pickup Brake Light Switch Replacement and Diagnosis
Keep your classic Hudson safe and its brake lights working with this guide to replacing your hydraulic brake light switch.
- The 1946-47 Hudson Pickup uses a hydraulic pressure switch, not a mechanical one by the pedal.
- Failure is a critical safety issue; replace the switch immediately if your brake lights don't work.
- Standard Ignition is the primary aftermarket brand available for this part.
- Brake bleeding is required after replacement to ensure the brakes work safely.
Signs of a Failing Brake Light Switch
The brake light switch on a vintage truck like the Hudson Pickup is a simple part, but it's critical for safety. When it fails, the symptoms are usually straightforward. Unlike modern cars, a failure here won't affect cruise control or your ability to shift gears, but it will create a serious safety hazard on the road.
- Brake Lights Don't Turn On: This is the most common and dangerous symptom. The internal contacts of the switch can wear out or burn, preventing it from completing the electrical circuit when you press the brake pedal.
- Brake Lights Stay On: The switch can also fail in the 'on' position, causing the brake lights to remain lit even when you're not braking. This can confuse other drivers and will drain your truck's battery.
- Brake Fluid Leak: The switch is a sealed unit, but with age, the seal can fail. You might notice brake fluid weeping from the switch body or around the electrical terminals. This is a serious issue that can lead to a loss of brake pressure.
Choosing the Right Aftermarket Switch
For a 1946-1947 Hudson Pickup, finding original factory (OEM) parts is nearly impossible. Your only realistic option is a new aftermarket reproduction part. The most common replacement available is from the brand Standard Ignition (Standard Motor Products).
Quality of Aftermarket Switches: It's important to be honest about quality. For many classic cars, owners in forums report that modern reproduction hydraulic switches can sometimes have a short service life. The internal contacts may not be as robust as the originals and can burn out over time due to the electrical current of the brake light bulbs. However, as the only readily available option, a new Standard Ignition switch is the correct choice for getting your truck safely back on the road. It is designed to fit and function like the original part.
Estimated Costs
| Part Type | Price Range |
|---|---|
| New Aftermarket (Standard Ignition) | $15 - $25 |
| Shop Labor | $50 - $100 |
Frequently Asked Questions (FAQ)
Where is the brake light switch located on my Hudson Pickup?
The brake light switch is not inside the cab. It is a hydraulic switch located in the engine bay, typically screwed directly into the master cylinder or a nearby brake line junction block. You will see two electrical wires connected to it.
Do I need to bleed the brakes after replacing the switch?
Yes. Because you are opening the hydraulic brake system to unscrew the old switch, air will get into the lines. After installing the new switch, you must bleed the brake system to remove all air. Failure to do so will result in a spongy brake pedal and unsafe braking performance.
Is this a difficult part to replace myself?
The replacement itself is not mechanically complex, but it requires the right tools and knowledge. You will need a wrench to fit the switch and tools for bleeding the brakes. If you are not comfortable bleeding your own brakes, it is best to have a qualified mechanic perform the job.
Are there any recalls for the brake light switch on my truck?
No, there are no official NHTSA recalls for the brake light switch on the 1946-1947 Hudson Pickup. This is common for vehicles of this era.
Technical Specifications
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.