Hydraulic Road Disc (HRD) Brake Hose Shortening and Bleed Manual

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Highly specialized tools and supplies are required for the replacement and maintenance of your SRAM components. We recommend that you have a qualified SRAM dealer work on your SRAM components.

Remove the wheel from the bicycle according to the wheel manufacturer’s instructions.

1. Remove the brake pads as shown in the Prepare the Caliper section.

2. Fully extend the Universal Bleed Block.

3. Install the bleed block into the caliper. Align the bleed block with the pad retaining bolt hole and install the pad retainer bolt.

4. Install the Pad Retainer Bolt.

5. Press down on the handle of the bleed block expanding the wedge until it cannot expand further.

Proceed with the bleed procedure.

6. Remove the pad retainer bolt.

7. Remove the Universal Bleed Block.

8. Clean the pistons and caliper before installing the brake pads.

9. Install the brake pads as shown in the Install the Brake Pads section.

1. Fully extend the universal bleed block.

Use the appropriate slot to measure your rotors (1.55 & 1.7 Min.)

2. Use the slot to determine if the rotor is at the minimum recommended width it must be replaced.

Rotor wear will vary by product model. This is normal. Change the rotor when changing the pad material, or when the thickness is less than the minimum stated on the rotor: 1.55 mm for 1.85 mm rotors and 1.7 mm for 2 mm thick rotors.

Remove the wheel from the bicycle according to the wheel manufacturer's instructions.

Secure a shop towel under the hose at the hose connection point to absorb any DOT brake fluid that may drip when the hose is disconnected.

Identify the hose connection location for your brake system by locating the compression nut at the lever (A) or at the caliper (B).

1-2. Place a 10 mm open end wrench onto the valve body, and an 8 mm flare nut wrench onto the compression nut to loosen and remove the compression nut and hose.

1-2. Use a 3 mm hex wrench to loosen and remove the brake lever from the aerobar.

3. Use an 8 mm open end wrench to loosen and remove the compression nut and hose.

4. Remove the hose from the lever.

1. Slide the hose boot up.

2. Use an 8 mm flare nut wrench to loosen and remove the compression nut.

3. Remove the hose.

The brakes should be installed with the hose properly routed and secured to the bicycle. To determine where to cut the hose, hold the hose up to the connection point with a length that creates a gentle bend in the hose and allows the handlebar to freely turn from side to side.

For internally-routed frames, remove the compression fitting, insert the hose through the frame, determine the proper length, then cut the hose.

1. Use a hydraulic hose cutter to cut the excess hose at the shift-brake lever.

Do not cut the hose at the caliper.

1. To determine where to cut the hose, measure 20 mm from the end of the aerobar.

2. Use a hydraulic hose cutter to cut the excess hose.

Do not cut the hose at the caliper.

1. Use a hydraulic hose cutter to cut the excess hose at the brake caliper.

1. Apply SRAM hydraulic disc brake grease to the hose barb threads.

2. Use a T8 TORX wrench to thread the Stealth-a-majig hose barb into the hose until it is flush with the end of the hose.

3. Thread the compression fitting over the hose barb, counter-clockwise, until it is flush or slightly lower than the hose barb.

The compression fitting is reverse threaded.

4. Apply SRAM hydraulic disc brake grease to the compression fitting and compression nut threads.

1. Install the hose into the valve body while threading the compression nut by hand.

2. Use a 10 mm open end wrench to hold the valve body, and use an 8 mm flare nut wrench to tighten the compression nut to 8 N·m (71 in-lb).

1. Install the hose into the brake lever while threading the compression nut by hand.

2. Use an 8 mm flare nut wrench to tighten the compression nut to 8 N·m (71 in-lb).

1. Install the hose firmly into the brake caliper while threading the compression nut by hand.

2. Use a 10 mm open end wrench on the banjo wrench flats, and use an 8 mm flare nut wrench to tighten the compression nut to 5 N·m (44 in-lb).

Proceed to the Bleed Instructions section for your brake caliper type.

SRAM recommends to bleed your brakes at least once a year to ensure optimal braking performance. Bleed your brakes more often if you ride frequently or ride on aggressive terrain that requires heavy braking. SRAM brake bleed videos can be found on sram.com/service

Identify the bleed procedure for your brake by locating the bleed port on your caliper.

Calipers with a bleed port (A) located outside of the caliper body bolts and farthest from the hose connection utilize the Bleeding Edge Bleed Procedure.

Calipers with a bleed port (B) located either near the hose connection or between the caliper body bolts (C) utilize the Non-Bleeding Edge Bleed Procedure.

Proceed to the Bleed Procedure section for your brake caliper type.

Identify the Bleeding Edge port type for your brake caliper.

To assemble a syringe for the brake lever, thread the bleed clamp assembly with a threaded bleed fitting onto one of the syringe plungers.

1. Fill the syringe for the brake lever with DOT 4 or 5.1 brake fluid until it is about 3/4 full.

Do not use mineral oil.

2-3. Hold the syringe upright, cover the tip with a shop towel, and depress the plunger just enough to remove any air bubbles. The syringe should still be close to 3/4 full.

4. Close the clamp on the syringe for the brake lever.

Bleeding Edge - Adapter bleed port: To assemble a syringe for the brake caliper, thread the Bleeding Edge tool assembly onto one of the syringe plungers.

Bleeding Edge - Threaded bleed port: prepare a syringe with a threaded bleed fitting.

5. Bleeding Edge - Adapter bleed port: To assemble a syringe for the brake caliper, thread the Bleeding Edge tool assembly onto one of the syringe plungers.

5. Bleeding Edge - Threaded bleed port: prepare a syringe with a threaded bleed fitting.

6. Fill the syringe for the brake caliper with a small amount of DOT brake fluid.

Do not use mineral oil.

7. Hold the syringe upright, cover the tip with a shop towel, and depress the plunger just enough to remove any air bubbles.

Remove the wheel from the bicycle according to the wheel manufacturer's instructions.

1. For levers with Contact Point Adjustment: Use a 5 or 2.5 mm hex wrench to rotate the contact adjust counter-clockwise until it stops against the snap ring.

2. Use a T10 TORX wrench to remove the bleed screw from the lever.

DOT brake fluid will drip out of the bleed port. Clean any DOT brake fluid that drips from the bleed port with water and a shop towel.

Aero:

1-2. Use a 3 mm hex wrench to loosen and remove the brake lever from the aerobar.

3. Use a T10 TORX wrench to remove the bleed screw from the lever.

DOT brake fluid will drip out of the bleed port. Clean any DOT brake fluid that drips from the bleed port with water and a shop towel.

4. Thread the 3/4 full syringe into the lever bleed port.

Remove the wheel from the bicycle according to the wheel manufacturer's instructions.

Monoblock Caliper:

1. Remove the e-clip.

2. Remove the pad retaining bolt.

3. Remove the brake pads from the caliper.

4. Install the bleed block.

5. Install the pad retainer bolt.

2-Piece Caliper:

1. Remove the e-clip.

2. Remove the pad retaining bolt.

3. Remove the brake pads from the caliper.

4. Install the bleed block.

5. Install the pad retainer bolt.

Bleeding Edge - Threaded:

6. Use a T10 TORX wrench to remove the bleed screw.

7. Thread the second syringe into the bleed port.

Bleeding Edge - Adapter bleed port:

6. Remove the bleed port cover.

7. Use a 4 mm hex wrench to loosen the bleed port valve 1/4 turn.

8. Gently retighten the bleed port.

Bleeding Edge- Adapter bleed port:

9. Install the syringe with the Bleeding Edge tool attachment into the bleed port. Push it into the bleed port until you hear and feel it click in place.

10. Rotate the Bleeding Edge tool attachment counter-clockwise one complete rotation to open the system.

Do not exceed two complete rotations.

1. Open the clamp on the syringe at the lever.

2. Hold the syringe vertically. Gently push the plunger down, stopping before all fluid is pushed from the syringe. Fluid will fill the syringe at the brake caliper.

3. Hold the syringe at the caliper vertically while slowly pulling the syringe plunger at the lever upward to draw fluid from the syringe at the caliper. Do not push fluid into the caliper with the caliper syringe.

Stop before any air enters the hose tube at the caliper.

If needed, repeat steps 2 and 3 until only a small amount of bubbles appear.

Bleeding Edge - Threaded bleed port:

4. Unthread the syringe from the caliper.

5. Use a T10 TORX to install the bleed screw.

Bleeding Edge - Adapter bleed port:

4. Rotate the Bleeding Edge tool attachment clockwise until it stops to close the system.

Bleeding Edge - Adapter bleed port:

5. Remove the syringe with the Bleeding Edge tool attachment from the bleed port by pulling the Bleeding Edge tool straight from the caliper.

Do not rotate the Bleeding Edge tool while removing.

Bleeding Edge - Adapter bleed port:

6. Use a 4 mm hex wrench to tighten the bleed port to 1.6 N·m (14 in-lb).

7. Install the bleed port cover.

8. Squeeze and release the lever blade.

9. Hold the syringe at the lever vertically. Firmly pull on the plunger to create a vacuum, then compress the plunger to pressurize the system. Repeat this process several times or until only a small amount of bubbles exit the system.

10. Lightly compress and release the plunger at the lever to equalize the system.

Repeat step 10 several times or until only a small amount of bubbles exit the system.

11. Close the clamp on the syringe at the lever.

12. Remove the syringe at the lever from the bleed port. Clean any DOT brake fluid that drips from the bleed port with water and a shop towel.

13. Use a T10 TORX to tighten the bleed screw to 1.6 N·m (14 in-lb). Clean any DOT brake fluid that drips from the bleed port with water and a shop towel.

Spray water on the shift-brake lever and caliper and clean them with a shop towel.

Aero:

14. Install the brake lever into the aerobar.

15. Use a 3 mm hex wrench to tighten the brake lever bolt.

1. Remove the pad retainer bolt.

2. Remove the bleed block.

3. Install the brake pads.

Install the wheel according to the wheel manufacturer's instructions.

4. Install the pad retainer bolt.

5. Install the e-clip.

6. Lightly squeeze (approx. 4 lbs) and release the lever blade repeatedly to advance the caliper pistons. On the first squeeze, the blade will come to the bar while the pistons advance; this is normal.

7. Check that the brake pads are equally spaced on either side of the rotor. If they are not, loosen the caliper bolts, align the caliper with the rotor, and tighten the bolts to 5 N·m (44 in-lb).

This completes the bleed procedure for brake calipers with a Bleeding Edge bleed port. For new brake pads and rotors, complete the Bed-in procedure.

1. Thread a bleed clamp assembly onto a syringe plunger. Assemble two syringes.

2. Fill the syringe for the brake caliper with DOT brake fluid until it is about 1/2 full.

Do not use mineral oil.

3. Hold the syringe upright, cover the tip with a shop towel, and depress the plunger just enough to remove any air bubbles. The syringe should still be close to 1/2 full.

4. Fill the syringe for the shift-brake lever with DOT brake fluid until it is about 1/4 full.

5. Hold the syringe upright, cover the tip with a shop towel, and depress the plunger just enough to remove any air bubbles. The syringe should still be close to 1/4 full.

Remove the wheel from the bicycle according to the wheel manufacturer's instructions.

Your product's appearance may differ from the images in this section. The bleed port location varies by model.

1. Remove the e-clip.

2. Remove the pad retaining bolt.

3. Remove the brake pads from the caliper.

4. Install the bleed block.

5. Install the pad retainer bolt.

6. Use a T10 TORX wrench to remove the caliper bleed screw.

7. Thread the 1/2 full syringe into the caliper bleed port.

1. Use a 2.5 mm wrench to adjust the lever blade so it measures less than 90 mm from the tip of the lever blade to an imaginary line drawn through the hood as shown.

2. Pull the hood back.

3. Use a T10 TORX wrench to remove the bleed screw from the lever.

DOT brake fluid will drip out of the bleed port. Clean any DOT brake fluid that drips from the bleed port with water and a shop towel.

4. Thread the 1/4 full syringe into the shift-brake lever bleed port.

1. Hold the caliper syringe vertically. Gently push the caliper plunger down, stopping when the caliper syringe is 1/4 full and the lever syringe is 1/2 full.

2. Close the clamp on the syringe at the shift-brake lever.

3. Use a toe strap or your hand to hold the lever blade to the bar. Do not release the lever until instructed to do so.

4. Hold the syringe at the caliper vertically. Firmly pull on the plunger to create a vacuum, then compress the plunger to pressurize the system. Repeat this process several times or until only a small amount of bubbles exit the system.

5. Apply pressure to the plunger at the caliper and slowly release the lever blade until it is fully extended.

6. Close the clamp on the syringe at the caliper.

7. Remove the syringe at the caliper from the bleed port. Clean any DOT brake fluid that drips from the bleed port with a shop towel.

8. Use a T10 TORX to tighten the bleed screw to 1.6 N·m (14 in-lb). Clean any DOT fluid that drips from the bleed port with water and a shop towel.

9. Open the clamp on the syringe at the shift-brake lever.

10. Hold the syringe at the lever vertically. Firmly pull on the plunger to create a vacuum, then compress the plunger to pressurize the system. Squeeze and release the brake lever ten times, allowing the lever to snap back to its starting position.

Repeat step 10 several times or until only a small amount of bubbles exit the system.

11. Compress and release the plunger at the lever to equalize the system.

12. Close the clamp on the syringe at the lever.

13. Remove the syringe at the lever from the bleed port. Clean any DOT brake fluid that drips from the bleed port with water and a shop towel.

14. Use a T10 TORX to tighten the bleed screw to 1.6 N·m (14 in-lb). Clean any DOT brake fluid that drips from the bleed port with water and a shop towel.

Spray water on the shift-brake lever and caliper and clean them with a shop towel.

1. Remove the bleed block.

2. Spray water on the brake lever and caliper and clean them with a shop towel.

3. Install the brake pads.

4. Install the pad retainer bolt.

5. Install the e-clip.

Install the wheel according to the wheel manufacturer's instructions.

6. Squeeze and release the lever blade three times to advance the caliper pistons. On the first squeeze, the blade will come to the bar while the pistons advance; this is normal.

7. Check that the brake pads are equally spaced on either side of the rotor. If they are not, loosen the caliper bolts, align the caliper with the rotor, and tighten the bolts to 5 N·m (44 in-lb).

This completes the bleed procedure for brake calipers with a Non-Bleeding Edge bleed port. For new brake pads and rotors, complete the Bed-in procedure at the end of the document.

If your brakes exhibit excessive lever throw or spongy feel, perform the following steps before bleeding the system:

1. Clamp the bicycle into a bicycle work stand.

2. Remove the wheel from the affected caliper.

3. Remove the brake pads. Measure the brake pads for wear. If the pads measure less than the minimum thickness, replace the pads.

4. Re-install the pad retainer bolt.

5a. For road brakes: Install the Piston Massage Spacer, Ultimate Piston Press, or the thicker side of the appropriate pad spacer through the caliper between all pistons.

5b. For MTB brakes: Install the Piston Massage Spacer, Ultimate Piston Press, or two 1.85 mm rotors through the caliper between all pistons.

6. Squeeze the brake lever several times until the pistons have advanced and contact the pad spacer. One piston may move faster than the other; that is okay. Continue to squeeze the lever until the pistons touch the spacer.

7. Remove the pad spacer, massage spacer, or piston press.

8. Use a plastic tire lever to push the pistons back into the caliper bores.

9. Repeat steps 4-7 until the pistons move freely.

10. Remove the spacer and pad retainer bolt from the caliper and reinstall the brake pads.

11. Install the thinner side of a pad spacer between the brake pads.

12. Squeeze the brake lever lightly 5 times (approximately 4 lbs.) until the pads contact the spacer. Remove the spacer.

13. Install the wheel.

14. Loosen the caliper mounting bolts.

15. Lightly squeeze (approximately 4 lbs.) the brake lever several times to position the brake pads to the proper distance from the rotor.

16. Center the caliper on the rotor, and tighten the caliper mounting bolts to the torque specified in the appropriate user manual.

17. Spin the wheel and check the brake function. The pistons should move freely and there should not be excessive brake lever throw.

If the brake lever was squeezed without a pad spacer or rotor installed in the caliper, the pad gap may have been reduced. If this happens the rotor might not have enough clearance in the caliper to rotate without rubbing. Perform this procedure to reset the pad gap:

1. Remove the wheel from the affected caliper.

2. Install the thicker side of a pad spacer between the brake pads.

3. Squeeze the brake lever hard 5 times (approximately 22 lbs/10 kg).

4. Remove the spacer from the caliper, and install the thinner side of a pad spacer between the brake pads.

5. Squeeze the brake lever lightly 5 times (approximately 4 lbs or less).

6. Remove the pad spacer.

7. Re-install the wheel, and re-center the caliper.

If there is still insufficient clearance between the brake pads and rotor after performing the pad gap reset procedure, perform this overnight procedure to reset the retraction distance between the caliper pistons:

1. Remove the wheel from the affected caliper.

2. Install the 3.8 mm side of a pad spacer between the brake pads and remove it without squeezing the brake lever.

3. Install the 2.4 mm side of a pad spacer between the brake pads.

4. Squeeze the brake lever lightly 5 times (approximately 4 lbs or less).

5. Allow the system to sit, untouched, for 12-24 hours.

6. Remove the pad spacer.

7. Re-install the wheel, and re-center the caliper.

All new brake pads and rotors should be put through a wear-in process called 'bed-in'. The bed-in procedure, which should be performed prior to your first ride, ensures the most consistent and powerful braking feel along with the quietest braking in most riding conditions. The bed-in process heats up the brake pads and rotors, which deposits an even layer of brake pad material (transfer layer) to the braking surface of the rotor. This transfer layer optimizes braking performance. To watch a video of the bed-in procedure, visit: SRAM: Disc Brake Bed-In Procedure.

1. Accelerate the bike to a moderate speed, then firmly apply the brakes until you are at walking speed. Repeat approximately twenty times.

2. Accelerate the bike to a faster speed, then very firmly apply the brakes until you are at walking speed. Repeat approximately ten times.

3. Allow the brakes to cool prior to any additional riding.

4. After the bed-in procedure has been performed, the caliper may need to be re-centered.