Chevrolet Blazer K5 Rear Drum Brake Hardware Kit Guide (1981-1985)
Everything you need to know before replacing the rear drum brake hardware on your 1981-1985 K5 Blazer.
- Always replace the drum brake hardware kit when installing new brake shoes; it's a cheap and critical part for safety and performance.
- Choose a quality aftermarket brand like ACDelco Professional or Raybestos for reliable, long-lasting performance.
- Be aware of the 1980-1981 brake pedal clip recall (NHTSA 80V150000) and verify it has been addressed on your Blazer.
- Ensure you are buying parts for the full-size K5 Blazer, not the smaller S-10 Blazer.
Is Your Blazer's Brake Hardware Worn Out?
On a truck as classic as the 1981-1985 K5 Blazer, the small parts often get overlooked. The springs and clips in your rear drum brakes have been flexing and holding tension for decades. They get tired, weak, and rusty. When this happens, your brakes won't work as they should. A broken spring can rattle around inside the drum, causing serious damage. Weak springs can cause the brake shoes to drag, leading to overheating and premature wear. It is standard practice and highly recommended by mechanics to replace the hardware kit every time you replace your brake shoes.
Important Vehicle Distinction: K5 vs. S-10 Blazer
This guide is specifically for the full-size K5 Blazer built on a truck chassis. During this period, Chevrolet also produced a smaller S-10 Blazer. The brake components for these two vehicles are completely different and are not interchangeable. Ensure you are purchasing parts for the correct K5 model.
Symptoms of Failing Drum Brake Hardware
- Scraping or Grinding Noises: A continuous scraping sound from the rear wheels, especially when not braking, can be a sign of a broken or weak spring allowing a shoe to drag against the drum.
- Brakes Feel Spongy or Soft: If the self-adjusters aren't working due to weak hardware, the shoes may be too far from the drum, requiring more pedal travel to engage.
- Parking Brake Feels Loose: The hardware is connected to the parking brake mechanism within the drum. Failure can cause the parking brake to not hold properly.
- Brakes Drag or Don't Release: After you let go of the brake pedal, weak return springs may not be strong enough to pull the shoes away from the drum. This causes constant friction, heat, and wear.
- Poor Self-Adjuster Function: The self-adjusting mechanism relies on spring tension to work. If you find your brakes need frequent manual adjustment, the hardware is likely worn out.
Choosing the Right Aftermarket Hardware Kit
Since your Blazer is over 40 years old, finding new Original Equipment (OEM) parts from GM is nearly impossible. The good news is that the aftermarket offers many high-quality, affordable options. Given the low cost, it's always worth spending a few extra dollars for a better-quality kit.
Brand Quality Tiers
- Tier 1 - Professional Grade (Recommended): Brands like ACDelco (Professional line) and Raybestos offer kits made to meet or exceed original specifications. They are known for using quality materials that ensure proper spring tension and longevity. These are the preferred choice for a reliable repair.
- Tier 2 - Standard Aftermarket: Brands such as Centric, Carlson, and Dynamic Friction provide reliable, budget-friendly kits that are a massive improvement over old, worn-out hardware. Store brands like Carquest and BrakeBest also fall into this category and are a perfectly acceptable choice for most owners.
- Tier 3 - Economy Brands: While brands like Dorman offer a wide variety of parts, they have a mixed reputation for the quality of their brake hardware. They may be the cheapest option, but for a safety-critical component that costs so little, sticking with a Tier 1 or Tier 2 brand is a better investment.
Pro Tip: Buy a Complete Kit
Ensure the kit you buy is for both rear wheels and includes the self-adjuster hardware. Some cheaper kits may be for one side only or exclude the adjuster components. A complete kit, often called a "Pro" kit, is the best value.
Known Issues, Recalls, and Bulletins
There are no specific recalls or Technical Service Bulletins (TSBs) for the drum brake hardware kit on the 1981-1985 Chevrolet Blazer. However, there is a critical, related safety recall that all owners should be aware of.
Recall Alert: Brake Pedal Retainer Clip (NHTSA ID 80V150000)
Some 1980-1981 GM trucks, including the Blazer, may have been built without the retainer clip for the brake pedal push rod. This could allow the brake pedal to disconnect from the master cylinder, causing a complete loss of braking. Check if this service has been performed on your vehicle. An authorized GM dealer or a qualified mechanic can inspect it for you.
Frequently Asked Questions (FAQ)
Do I really need to replace the hardware when I change my brake shoes?
Yes, absolutely. It is the professional standard. The springs lose tension over time, and for a low price of $10-$30, you get peace of mind that your new shoes will function correctly and won't wear out prematurely due to dragging. Reusing old hardware is asking for problems.
What tools are needed to replace the drum brake hardware?
You will need standard hand tools, a floor jack, and jack stands. However, you will also need a few specialty brake tools to make the job possible and safe: brake spring pliers, a hold-down spring tool, and a brake adjuster spoon. These tools are not expensive and are essential for fighting the strong springs in the kit.
What is the most common mistake when replacing drum brake hardware?
The most common mistake is not remembering how the parts go back together. It's a puzzle of springs and clips. Before you remove any parts, take several clear pictures from different angles with your phone. Also, only work on one side of the vehicle at a time. That way, you can use the other side as a reference.
Should I lubricate the new hardware?
Yes. You should apply a small amount of high-temperature brake lubricant to the contact points on the backing plate where the brake shoes rub. There are typically six raised pads on the backing plate that need lubrication. This prevents squeaking. Do NOT get any lubricant on the brake shoes or the drum friction surface.
Technical Specifications
The kit should contain all springs, pins, clips, and self-adjuster components for both rear wheels. Common aftermarket part numbers include ACDelco 18K560, Raybestos H7046, Dorman HW2324, and Carlson H2324. Always verify fitment for your specific K5 Blazer model (2WD vs 4WD) as there can be minor differences.
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.
- Chevrolet Blazer:
- Is Your Blazer's Brake Hardware Worn Out?
- Important Vehicle Distinction: K5 vs. S-10 Blazer
- Symptoms of Failing Drum Brake Hardware
- Choosing the Right Aftermarket Hardware Kit
- Brand Quality Tiers
- Pro Tip: Buy a Complete Kit
- Known Issues, Recalls, and Bulletins
- Recall Alert: Brake Pedal Retainer Clip (NHTSA ID 80V150000)
- Frequently Asked Questions (FAQ)
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