04/03/2003
Maintaining your vehicle's braking system is paramount for safety, and replacing brake pads is a fundamental aspect of this upkeep. However, modern vehicles often feature sophisticated systems, and the integral parking brake – particularly the electronic parking brake (EPB) – introduces a unique set of challenges compared to traditional setups. This guide will walk you through the process of replacing brake pads on a vehicle equipped with an integral parking brake, ensuring you approach the task with confidence and the right knowledge. Remember, while this guide provides detailed instructions, familiarity with basic automotive mechanics and a commitment to safety are essential.
Understanding your specific vehicle's braking system is the first critical step. An integral parking brake means the parking brake mechanism is built directly into the main service brake caliper, often electronically controlled. This differs significantly from older systems where a separate cable-actuated drum brake might be housed within the rear disc rotor (known as a 'drum-in-hat' design). For EPB systems, simply trying to compress the caliper piston like a standard brake will likely cause damage, as the piston often needs to be wound back or retracted electronically.
Essential Tools and Materials for the Job
Before you even think about jacking up your car, gathering the correct tools and materials is crucial. Being well-prepared will make the job smoother and safer. Here’s a list of what you’ll likely need:
- Vehicle Owner's Manual: Invaluable for specific procedures and torque specifications.
- Jack and Jack Stands: Absolutely essential for safely lifting and supporting the vehicle. Never work under a vehicle supported only by a jack.
- Wheel Chocks: To prevent the vehicle from rolling.
- Lug Wrench: To remove and reinstall wheel nuts.
- Socket Set and Ratchet: For caliper bolts and other fasteners.
- Torque Wrench: Critical for tightening wheel nuts and caliper bolts to the manufacturer’s specifications. Overtightening or undertightening can be dangerous.
- Brake Pad Spreader or C-Clamp: For compressing pistons on non-EPB calipers, or for holding pads while winding back EPB pistons.
- Brake Piston Wind-Back Tool Kit: This is a must-have for most EPB systems, as the piston needs to be rotated as it's compressed.
- Diagnostic Scan Tool (OBD-II Scanner with EPB Functionality): For electronically retracting and resetting EPB systems. This is often the most critical and specialised tool.
- New Brake Pads: Ensure they are the correct type and specification for your make, model, and year.
- Brake Cleaner: To clean components and remove grease.
- Wire Brush and File: For cleaning caliper carriers and old rust.
- Brake Lubricant (High-Temperature, Synthetic): For caliper slides, pad shims, and contact points.
- Gloves and Safety Glasses: Personal protective equipment is non-negotiable.
- Container: To catch any spilled brake fluid (though unlikely if done correctly).
Safety First: Non-Negotiable Precautions
Working with brakes involves heavy components and critical safety systems. Always prioritise safety:
- Ensure the vehicle is on a flat, level, and solid surface.
- Engage the parking brake (if it's not the one you're working on, or ensure it's fully disengaged if it is).
- Place wheel chocks on the wheels that will remain on the ground.
- Loosen the wheel nuts slightly *before* jacking up the vehicle.
- Once lifted, securely support the vehicle with jack stands. Never rely solely on the jack.
- Disconnect the car's battery if you are concerned about accidental EPB engagement, especially if you don't have a scan tool to control it.
- Allow the brakes to cool down if the car has just been driven.
- Never ingest brake dust or fluid. Wear appropriate PPE.
The Step-by-Step Procedure: A Detailed Guide
This section outlines the process, with particular attention to the nuances of an integral electronic parking brake system.
1. Preparation and Wheel Removal
With the vehicle safely on jack stands and wheels chocked:
- Loosen the lug nuts on the wheel you’re working on while the car is still on the ground.
- Raise the vehicle with the jack and position the jack stands securely under the designated jacking points.
- Remove the lug nuts completely and carefully take off the wheel. Store it safely out of the way.
2. Disengaging the Electronic Parking Brake (EPB)
This is arguably the most crucial step for integral EPB systems. Do not skip this.
- Using a Diagnostic Scan Tool: This is the recommended and safest method. Connect your OBD-II scan tool to the vehicle's diagnostic port (usually under the dashboard). Navigate through the menus to find the 'Electronic Parking Brake' or 'Service Mode' function. Follow the on-screen prompts to retract the EPB pistons. This will electronically unwind the parking brake mechanism, allowing the caliper piston to be safely compressed without damage.
- Manual Release (if available): Some vehicles may have a manual release procedure detailed in the owner's manual, often involving a fuse or a specific sequence. However, this is less common with modern EPB systems, and a scan tool is generally required.
Once the EPB is in service mode, you should hear the actuators retract, and the caliper piston will be ready for compression.
3. Removing the Brake Caliper
- Locate the caliper bolts. These are typically two bolts on the back of the caliper that secure it to the caliper carrier.
- Using your socket wrench, carefully remove these bolts. You might need to hold the guide pins with another wrench to prevent them from spinning.
- Once the bolts are removed, gently slide the caliper off the brake disc. Do not let the caliper hang by the brake hose, as this can damage the hose. Use a bungee cord or wire to suspend it from the suspension component.
- Remove the old brake pads from the caliper carrier. Note how they were seated to ensure correct reinstallation.
4. Compressing the Piston (EPB Specific)
This step requires the special brake piston wind-back tool kit.
- Identify the correct adapter plate from your kit that matches the notches or depressions on your caliper piston face.
- Attach the adapter to the wind-back tool and place it against the piston.
- Rotate the handle of the tool, simultaneously pushing and rotating the piston back into the caliper body. This is distinct from simply pushing a standard caliper piston. The piston must rotate to retract the internal parking brake mechanism.
- Continue until the piston is fully retracted, flush with the caliper body. This creates space for the new, thicker brake pads.
5. Preparing the Caliper Carrier and Installing New Pads
- Carefully remove the old hardware (shims, clips) from the caliper carrier.
- Using a wire brush and file, thoroughly clean any rust, dirt, or old grease from the caliper carrier where the brake pads sit. This ensures the new pads can move freely.
- Apply a thin layer of high-temperature synthetic brake lubricant to the clean contact points on the caliper carrier and the back of the new pad shims (if supplied). Avoid getting lubricant on the pad friction material.
- Install the new hardware onto the caliper carrier.
- Insert the new brake pads into the caliper carrier, ensuring they fit snugly but can still slide freely. Double-check that any wear indicators are positioned correctly.
6. Reassembly
- Carefully slide the caliper back over the new brake pads and disc. Ensure the brake hose isn't twisted or strained.
- Align the caliper with the mounting holes and reinsert the caliper bolts.
- Tighten the caliper bolts to the manufacturer’s specified torque using your torque wrench. Refer to your owner's manual for these critical values.
- Reinstall the wheel, hand-tighten the lug nuts, then lower the vehicle until the wheel just touches the ground.
- Tighten the lug nuts in a star pattern to the manufacturer’s specified torque.
- Fully lower the vehicle and remove the jack and jack stands.
7. Post-Installation Procedures and Bedding-In
- Retract EPB Service Mode: Reconnect your diagnostic scan tool and follow the prompts to exit the EPB service mode. The EPB actuators will reset, and the system will be operational again.
- Pump the Brake Pedal: Before driving, get into the car and pump the brake pedal several times until it feels firm. This pushes the caliper pistons out and seats the new pads against the disc.
- Check Brake Fluid Level: As the pistons were retracted, brake fluid would have been pushed back into the reservoir. Check the fluid level and top up if necessary, but be careful not to overfill.
- Bedding-In New Pads: This is a critical step for optimal performance and longevity. Drive the vehicle cautiously in a safe area. Perform several moderate stops from about 30 mph down to 5 mph, avoiding hard braking. Then, perform a few firmer stops from 50 mph down to 10 mph. Allow the brakes to cool between each set of stops. Avoid aggressive braking or prolonged braking for the first 100-200 miles. This process transfers a thin layer of pad material onto the rotor, ensuring even contact and preventing glazing.
Types of Brake Pads Available
While the exact part numbers vary immensely by vehicle, brake pads generally fall into a few categories. For your 1987-1988 Chevrolet R20 Suburban, for instance, the original information indicates 'Disc Brake Pad' and 'Drum Brake Shoe' with various grades. For modern vehicles with integral parking brakes, you will almost exclusively be looking at disc brake pads. Here’s a general overview of common types:
| Pad Type | Characteristics | Pros | Cons |
|---|---|---|---|
| Organic (NAO) | Made from fibres like glass, rubber, carbon, Kevlar, and high-temp resins. | Quiet, less dust, good initial bite. | Lower friction, wear faster, less effective at high temperatures. |
| Semi-Metallic | 30-65% metal (copper, iron, steel, brass) blended with organic fillers and friction modifiers. | Good stopping power, good heat transfer, durable. | Noisier, more brake dust, can be harder on rotors. |
| Ceramic | Composed of ceramic fibres, filler materials, and bonding agents. | Very quiet, low dust, long-lasting, stable across temps. | More expensive, can require more pedal pressure, less effective in extreme cold. |
| Low-Metallic NAO | A hybrid, with small amounts of metal for better braking and heat transfer than pure organic, but less noise/dust than semi-metallic. | Balance of performance, less noise than semi-metallic. | Can produce more dust than ceramic. |
Always consult your vehicle's specifications or a reputable parts supplier to ensure you purchase the correct pad type and fitment for your specific car. The information provided about 'SGD52C', 'MGD52C', etc., refers to specific part numbers and grades for particular vehicles, highlighting the necessity of precision when selecting replacement parts.
Troubleshooting Common Issues
- Piston Won't Retract: If the piston doesn't retract even after using the scan tool, re-check that the EPB is in service mode. Ensure you are using the correct wind-back tool and adapter. If still stuck, there might be an issue with the caliper itself, or the EPB motor.
- Brake Pedal Feels Spongy: This usually indicates air in the brake lines. You may need to bleed the brake system.
- New Squealing Noise: New pads can sometimes squeal slightly during the bedding-in period. If it persists, ensure all hardware is correctly installed and lubricated, and that the pads are properly seated.
- EPB Warning Light: If an EPB warning light comes on after the procedure, it likely means the system wasn't properly exited from service mode or needs a reset via the scan tool.
When to Call a Professional
While DIY brake pad replacement can save money, there are times when calling a professional mechanic is the wisest choice:
- If you lack the necessary tools, especially a compatible diagnostic scan tool for EPB systems.
- If you encounter unexpected difficulties, such as seized bolts or damaged components.
- If the brake pedal remains spongy after pumping and you're not comfortable bleeding the brakes.
- If you suspect a more serious issue with the braking system beyond just pad wear.
- If you are not confident in your ability to perform the task safely and correctly.
Frequently Asked Questions (FAQs)
Q: How often should I replace my brake pads?
A: This varies greatly depending on driving style, vehicle type, and pad material. Generally, front pads last 20,000-60,000 miles, and rear pads (especially with EPB) can last longer. Always inspect them during routine maintenance.
Q: Can I replace just one set of pads (front or rear)?
A: Yes, it's common to replace front pads more often than rear pads. However, always replace pads as an axle set (both left and right on the same axle) to ensure even braking performance.
Q: Do I need to replace brake discs when replacing pads?
A: Not always. Discs should be replaced if they are below the minimum thickness specification, warped, or severely scored. Many shops recommend replacing them in pairs with pads for optimal performance, but it's not strictly necessary if they are in good condition.
Q: What happens if I don't retract the EPB electronically?
A: Attempting to simply push the piston back on an active EPB system will likely damage the internal parking brake mechanism, the caliper, or the EPB motor, leading to costly repairs.
Q: Is brake fluid important for EPB systems?
A: Yes, brake fluid is vital for all hydraulic braking systems, including those with EPB. It transmits the force from the pedal to the calipers. Ensure the fluid is clean and at the correct level.
Q: What is the 'bedding-in' process?
A: Bedding-in, or 'burnishing,' is the process of gently heating and cooling new brake pads and rotors to transfer a thin, even layer of friction material from the pad to the rotor. This creates an optimal contact surface, improves braking performance, and reduces noise and vibration.
Conclusion
Replacing brake pads on a vehicle with an integral parking brake, particularly an electronic one, is a task that requires precision, the right tools, and a strict adherence to safety protocols. By following this comprehensive guide, understanding the specific requirements of your vehicle's EPB system, and taking the necessary precautions, you can confidently undertake this maintenance task. Remember, your brakes are your most important safety feature, so ensure the job is done correctly. If in doubt, always consult a qualified mechanic.
If you want to read more articles similar to Mastering Integral Parking Brake Pad Replacement, you can visit the Brakes category.