Replacing Brake Pads on Force eTap AXS D2 HRD: A DIY Guide

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The SRAM Force eTap AXS D2 HRD [paid link] is a hydraulic disc brake system designed for high-performance road cycling. With its wireless electronic shifting and refined ergonomics, maintaining optimal braking performance is critical. Replacing worn brake pads is a routine but essential maintenance task to ensure consistent stopping power and rider safety. This guide offers a detailed walkthrough on how to replace brake pads on the Force eTap AXS D2 HRD system, covering preparation, installation, adjustment, and troubleshooting.

Tools Required

  • 2.5 mm and 5 mm hex wrenches
  • Flat-blade screwdriver or plastic tire lever
  • Needle-nose pliers
  • Isopropyl alcohol (99%)
  • Clean, lint-free cloths
  • New brake pads (compatible with SRAM HRD calipers)
  • Pad spreader or plastic tire lever
  • Torque wrench (Nm scale)
  • Optional: Bleed kit (if pistons are sticky or require reset)

Understanding Pad Wear and When to Replace

Brake pads on the Force eTap AXS D2 HRD system typically wear down over time due to friction with the rotor. The minimum pad thickness, including backing plate, should not fall below 3 mm. Riders should inspect pads regularly and replace them when braking becomes noisy, inconsistent, or if the pad material drops below the wear indicator line.

Early signs of wear include a noticeable loss in modulation, increased braking noise, or the feeling of “grabbing” rather than a smooth deceleration. If in doubt, it’s safer to replace pads early, especially before long rides or in wet weather conditions where pad wear accelerates.

Removing the Wheel and Old Pads

Begin by placing the bike in a work stand with the wheel to be serviced elevated. If you are servicing the front caliper, turn the handlebars to give easier access.

To remove the brake pads:

  1. Loosen the 2.5 mm hex bolt securing the pad retention pin.
  2. Slide out the pin while supporting the pads from below.
  3. Gently pull the pads and spring clip assembly out of the caliper body.
  4. Inspect the caliper interior for debris or contamination and clean with isopropyl alcohol.

If pads are stuck due to piston retraction issues, use a flat-blade screwdriver wrapped in a cloth to gently lever them out without damaging the caliper.

Cleaning and Resetting the Pistons

Before installing new pads, the pistons must be retracted to their neutral position. This creates space for the new, thicker pads.

  • Insert a plastic tire lever or pad spreader tool between the pistons and gently push them back into the caliper body.
  • Apply even pressure to both pistons simultaneously to avoid uneven retraction.
  • If the pistons are sticky or unresponsive, a bleed service may be required before proceeding.

After resetting the pistons, clean the caliper thoroughly with isopropyl alcohol and allow it to dry completely.

Installing New Brake Pads

New pads should be handled carefully to avoid contamination. Use gloves or clean hands and keep them free from grease or oil.

  1. Align the new pads and spring clip into the caliper as a single unit.
  2. Slide them in gently until they seat against the pistons.
  3. Insert the pad retention pin through the holes in the caliper and pads.
  4. Tighten the retention bolt to SRAM’s torque specification (2-3 Nm).

Double-check that the pads move freely within the caliper and are not rubbing against the rotor when the wheel is reinstalled.

Reinstalling the Wheel and Aligning the Caliper

Once the new pads are installed:

  • Reinstall the wheel and ensure the rotor is seated correctly between the pads.
  • Squeeze the brake lever a few times to center the pads against the rotor.
  • If the caliper needs realignment, loosen the two 5 mm bolts securing it to the frame.
  • With the rotor centered, squeeze the brake lever and tighten the bolts incrementally.
  • Ensure there is no rotor rub or noise when spinning the wheel.

Bedding In New Pads

New brake pads require a bedding-in process to optimize performance and longevity. This process deposits a layer of pad material onto the rotor surface, ensuring full contact.

  • Ride at moderate speed (20-25 km/h) and perform 20 smooth, controlled stops from that speed to nearly a full stop.
  • Allow brief recovery time between each stop to avoid overheating.
  • Avoid abrupt or emergency braking during this process.

Proper bedding-in improves initial bite and consistent braking feel under load.

Troubleshooting Common Issues

If issues arise during or after pad replacement, consider the following:

Rotor rub: Often due to caliper misalignment or piston asymmetry. Re-align the caliper or reset pistons.

Squealing brakes: Usually caused by contamination. Clean rotor and pad surfaces with alcohol or replace if contaminated.

Soft lever feel: Indicates air in the hydraulic line. Bleed the system using SRAM’s HRD bleed kit.

Pad drag: Caused by sticking pistons or improper pad installation. Ensure pistons are fully reset and pads are properly seated.

Performance Customization

For riders seeking specific braking characteristics, consider the following pad options:

  • Organic pads: Quieter operation and better modulation in dry conditions. Ideal for road cycling.
  • Sintered (metallic) pads: Superior performance in wet or muddy conditions. Increased durability but noisier.
  • Semi-metallic pads: A balance between quiet braking and improved wear resistance.

Choosing the right pad compound allows customization based on riding environment and preference.

Compatibility Considerations

The SRAM Force eTap AXS D2 HRD uses flat-mount hydraulic calipers. When selecting pads:

  • Ensure the backing plate and retention design match SRAM HRD specifications.
  • Confirm rotor diameter compatibility (usually 160 mm or 140 mm) to maintain proper clearance.
  • Avoid mixing different pad compounds front and rear unless tested, as it may result in uneven braking response.

Using pads not rated for SRAM HRD systems may compromise braking performance and void warranty coverage.

Comparison with Other SRAM Models

Compared to Red eTap AXS HRD [paid link], the Force variant uses the same pad interface but may differ slightly in material finish and weight. Functionally, the braking systems are interchangeable, but Red models might include higher-end pad materials or lightweight hardware.

Rival eTap AXS HRD [paid link] also shares pad compatibility, though it may use a less refined caliper body. Force HRD strikes a balance between affordability, performance, and serviceability, making it a preferred choice for serious road cyclists.

Final Inspection and Test Ride

After installation, perform a complete system check:

  • Confirm rotor and pad clearance on both sides.
  • Check lever feel and brake engagement.
  • Inspect for any fluid leaks or unusual noises.

Take the bike for a short test ride in a safe area. Perform moderate braking tests and listen for any issues. If all checks out, your SRAM Force eTap AXS D2 HRD brakes are ready for peak performance.

Regular inspection and timely pad replacement will keep your braking smooth and reliable, ensuring confidence on every ride.