Upgrade Your Motorcycle Brakes: A DIY Guide

Revitalising Your Ride's Stopping Power: A Brake Pad Replacement Guide

Motorcycle brakes are arguably the most critical safety component on any bike. They are the first line of defence, and their performance can make the difference between a controlled stop and a potentially dangerous situation. Many riders, especially those with performance-oriented machines like the Kawasaki ER-6n, often find the stock brake pads to be somewhat lacking in outright stopping power. This was certainly the experience of one rider after a significant rebuild of his accident-damaged bike. The rear brake, in particular, felt weak, requiring excessive pedal pressure to achieve even a modest deceleration, and failing to lock up the wheel. This article delves into the process of replacing brake pads, using a real-world example of upgrading to Brembo pads, and offers practical advice for a successful DIY job.

Why Upgrade Your Brake Pads?

The decision to upgrade brake pads often stems from a desire for enhanced stopping performance. Stock pads, while adequate for general riding, may not offer the bite, feel, and fade resistance that enthusiastic riders or those carrying heavier loads demand. In the case of the Kawasaki ER-6n, owners frequently report that the standard pads are a compromise, with the rear brake being particularly underpowered. Upgrading to aftermarket options from reputable brands like EBC or Brembo can significantly improve:

• Braking Feel: A more consistent and predictable lever or pedal feel.
• Stopping Power: Reduced stopping distances, especially under hard braking.
• Fade Resistance: Better performance during prolonged or heavy braking, such as on descents or track days.
• Durability: Some aftermarket pads may offer longer life, though this can vary depending on the compound.

The cost-effectiveness of upgrading can also be a factor. As seen in the example, the cost of a few sets of premium pads can be surprisingly reasonable, especially when compared to the potential benefits. It’s worth noting that the choice of brake fluid can also play a role in overall brake system performance.

Choosing the Right Brake Pads

Selecting the correct brake pads is paramount. Manufacturers often offer different compounds for various riding styles:

When purchasing, ensure you get the exact part number for your specific make, model, and year. Websites can sometimes be confusing, so contacting a reputable supplier or manufacturer directly is advisable. The example rider found Brembo's website a bit challenging but received excellent assistance from Orion Motorsports. The specific Brembo pads purchased were:

• Front Right: 07KA18.SA
• Front Left: 07KA19.SA
• Rear: 07KA16.SP

It's also important to check the condition of the packaging. Poor packaging, as experienced by the rider, can lead to damaged goods. Fortunately, good customer service can rectify such issues promptly.

Essential Tools and Supplies

Before you begin, gather all the necessary tools and supplies to ensure a smooth process. Having everything on hand will prevent interruptions and potential mistakes.

• New Brake Pads: The correct ones for your motorcycle.
• Brake Fluid: Ensure you have enough for bleeding the system. Check your owner's manual for the correct type (e.g., DOT 3, DOT 4).
• Torque Wrench: Crucial for tightening bolts to the manufacturer's specifications, preventing over or under-tightening.
• Hex/Allen Keys: Typically 12mm hex for front calipers and 6mm Allen for rear calipers, though sizes can vary.
• Brake Cleaner Spray: For cleaning caliper components and discs.
• Brake Fluid Container: A clean receptacle to catch old fluid during bleeding.
• Gloves: To protect your hands from brake fluid and dirt.
• Rags/Shop Towels: For wiping up spills and cleaning parts.
• Patience: This is a DIY job, and taking your time is key to a good result.
• Optional: Piston compressor tool (if pistons are difficult to retract), new banjo washers (recommended by some manuals).

Step-by-Step Brake Pad Replacement (General Procedure)

While specific steps may vary slightly between motorcycle models, the general process for replacing brake pads is as follows. It's always best to consult your bike's service manual or reliable online resources like YouTube tutorials for model-specific instructions.

1. Preparation and Caliper Removal

• Ensure the motorcycle is securely supported on a stand.
• Locate the brake calipers on both the front and rear wheels.
• Crucially: DO NOT operate the brake lever or pedal after removing the caliper until it is fully reassembled and mounted back on the bike. This can push the pistons out too far or cause other issues.
• Remove the caliper mounting bolts. For the front, this is typically a 12mm hex head; for the rear, it's often a 6mm Allen head. You may need to remove the caliper from its mounting bracket first.
• Once the caliper is free, carefully slide it off the brake disc. Let it hang by the brake line or support it to avoid stressing the line.

2. Old Pad Removal

• Identify and remove the retaining clip or pin that holds the brake pads in place. This is often an 'R'-clip or a cotter pin.
• Slide out the slider pin(s) that guide the caliper.
• With the retaining elements removed, you should be able to slide the old brake pads out of the caliper. They might be held in by the piston pressure, requiring a gentle wiggle or levering.
• Note the orientation of the old pads and any shims or anti-rattle clips.

3. Cleaning and Lubrication

• Clean the caliper body, slider pins, and the area where the pads sit using brake cleaner spray. Ensure all dust and debris are removed.
• Inspect the slider pins for damage or wear. If they are rough or corroded, consider replacing them.
• Apply a thin layer of high-temperature brake grease to the slider pins and the back of the new brake pads (where they contact the caliper piston and body).
• Crucially: Avoid getting any grease on the friction material of the brake pads or the brake disc surface. This will severely compromise braking performance.

4. New Pad Installation

• Slide the new brake pads into the caliper, ensuring they are seated correctly. Pay attention to any specific orientation or springs that came with the new pads or the original setup.
• Reinstall the slider pin(s), ensuring they pass through the caliper and the new pads correctly.
• Reinstall the retaining clip or pin to secure the pads.

5. Caliper Reinstallation and Torqueing

• Carefully slide the caliper back over the brake disc, aligning the mounting holes.
• Reinstall the caliper mounting bolts.
• Using a torque wrench, tighten the mounting bolts to the manufacturer's specified torque. For the Kawasaki ER-6n, the example mentions 34Nm for the front and 25Nm for the rear, but always verify this for your specific model.

6. Piston Retraction (Important Consideration)

As brake pads wear, the caliper pistons extend further out. When installing new, thicker pads, you may need to retract the pistons to make space. This is often done by carefully prying them back into the caliper body. Some mechanics recommend opening the brake bleed valve slightly while retracting the pistons to allow fluid to flow back into the reservoir and prevent over-pressurisation. However, this requires careful management of brake fluid and subsequent bleeding.

The example rider initially skipped retracting the pistons on one caliper, leading to a dragging brake and an overheated disc. This highlights the importance of ensuring the caliper can move freely and doesn't maintain constant contact with the disc when the brakes are not applied.

Bleeding the Brakes

After installing new pads, and especially if you opened the bleed valve or removed the caliper from the brake line, bleeding the brake system is essential to remove any air bubbles and ensure optimal performance. The process typically involves:

1. Ensuring the brake fluid reservoir is topped up.
2. Attaching a clear hose to the bleed nipple on the caliper and placing the other end in a container with some brake fluid.
3. Opening the bleed nipple slightly.
4. Operating the brake lever or pedal to push fluid through the system.
5. Closing the bleed nipple before releasing the lever/pedal.
6. Repeating until no air bubbles are seen in the fluid.
7. Top up the reservoir to the correct level.

The rider in the example had to perform a more involved process of rebuilding the rear caliper, which included removing the piston, replacing seals, and then thoroughly bleeding the system.

Post-Replacement Checks and Test Ride

Once the new pads are installed and the caliper is re-mounted:

• Pump the brake lever/pedal several times until a firm pressure is felt. This ensures the pistons are pushed out against the new pads.
• Check for leaks around the caliper and banjo bolts.
• Take the bike for a slow, cautious test ride. Gently apply the brakes at low speeds to feel their response.
• Listen for any unusual noises, such as grinding or scraping.
• Check the temperature of the discs after the test ride. They should be warm, but not excessively hot to the touch, which could indicate dragging.

Troubleshooting Common Issues

DIY brake jobs can sometimes present challenges. Here are a few common issues and their potential solutions:

1. Dragging Brakes

• Cause: Caliper pistons not fully retracted, causing the pads to remain in contact with the disc.
• Solution: Ensure pistons are fully retracted. If necessary, open the bleed valve slightly while pushing them back. Check for warped caliper mounting brackets or discs.

2. Weak or Inconsistent Braking

• Cause: Air in the brake lines, insufficient fluid, worn pads (even if new ones were installed, check for incorrect fitment or contamination), or issues with the master cylinder.
• Solution: Re-bleed the brakes thoroughly. Check fluid levels and condition. Verify correct pad installation and ensure no grease has contaminated the friction surfaces.

3. Squealing Brakes

• Cause: Vibration between the pad material and the disc. Can be caused by uneven pad wear, lack of anti-squeal paste, or contamination.
• Solution: Ensure pads are installed correctly with any included shims or anti-rattle clips. Apply a small amount of high-temperature brake grease to the back of the pads (away from the friction material). Clean the caliper and disc surfaces. Sometimes, new pads simply need a bedding-in period.

4. Overheated Discs

• Cause: Caliper dragging, as mentioned above.
• Solution: Address the cause of the dragging. Ensure proper retraction of pistons and free movement of the caliper.

Bedding-In New Brake Pads

New brake pads, especially performance-oriented ones, often require a bedding-in procedure to achieve optimal performance. This involves a series of moderate to firm brake applications to gently transfer a thin layer of pad material onto the disc surface, creating a uniform contact area. Follow the pad manufacturer's specific recommendations, but a common method includes:

• Perform 8-10 moderate stops from around 50-60 kph (30-37 mph), gradually increasing the intensity.
• Follow these with 2-3 harder stops from slightly higher speeds.
• Avoid full-force braking or coming to a complete stop during the bedding-in process.
• Allow the brakes to cool down completely without prolonged idling with the brakes applied.

The rider noted that the Brembo front pads showed significant improvement and were expected to improve further over the first 160 km (approx. 100 miles) of riding.

Final Thoughts on the Brembo Upgrade

The experience shared highlights that while upgrading brake pads, particularly for the front, can yield substantial improvements in braking feel and power, results can vary. The front Brembo pads were a resounding success, transforming the bike's stopping capability and inspiring confidence. However, the rear pads made little discernible difference, suggesting that the root cause of the weak rear braking might have been a sticking caliper, as later addressed by the rider through a rebuild. This underscores the importance of diagnosing the underlying issue before assuming new pads alone will solve performance problems.

For riders seeking to improve their motorcycle's braking, a DIY brake pad replacement is a rewarding task. By following proper procedures, using the right tools, and understanding potential pitfalls, you can significantly enhance your bike's safety and performance. Remember, when in doubt, always consult a professional mechanic.

Frequently Asked Questions

Q1: How often should I replace my motorcycle brake pads?

A1: Brake pad life varies greatly depending on riding style, conditions, and the type of pads used. Inspect them regularly (e.g., during tire changes or every few thousand miles). Look for a minimum pad thickness of around 1-2mm above the backing plate, or as specified by your manufacturer.

Q2: Can I mix different types of brake pads on my bike?

A2: It is generally not recommended to mix different types or brands of brake pads on the same axle (front or rear). For best performance and balanced braking, use the same type of pads on both sides of the front wheel and on the rear wheel.

Q3: What happens if I don't replace worn brake pads?

A3: Worn brake pads can lead to significantly reduced braking performance, longer stopping distances, and potential damage to the brake discs (rotors) if the friction material wears down to the metal backing plate.

Q4: Is it safe to do this myself?

A4: Yes, replacing brake pads is a manageable DIY task for many riders with basic mechanical aptitude and the right tools. However, if you are unsure at any stage, it's always best to seek professional assistance from a qualified motorcycle mechanic.

Q5: Do I need to bleed my brakes every time I change the pads?

A5: You only need to bleed the brakes if you have opened the brake line, removed the caliper from the line, or if there is air in the system. If you simply compress the pistons and swap the pads without disturbing the fluid lines, bleeding may not be necessary, but it's good practice to check the fluid level and top up if needed.

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