SRAM DB8 brake: change the pads, align the caliper and bleed it with mineral oil

How to confirm you have a DB8, not a DOT brake

The serial number is laser etched on the underside of the caliper body. SRAM model numbers read like DB-DB8-A1: disc brake, DB platform, model 8, version A1. The two DB8 versions are DB-DB8-A1 (DB8) and DB-DB8-B1 (DB8 Stealth). The lever clamps on with SRAM's MatchMaker X system.

Look for green. SRAM dyes Maxima Mineral Brake Oil green, and the seals at the bleed ports and on the mineral oil bleed kits are green to match. SRAM's DOT fluid is yellow. The DB8 caliper also has its own bleed ports that only fit the SRAM Mineral Oil bleed kit, so a DOT bleed kit will not fit.

This page does not cover SRAM's DOT brakes. SRAM uses DOT 4 or DOT 5.1 fluid in all its current DOT brakes, including every Level (Level, T, TL, TLM, Ultimate, Level Stealth 2-piston and 4-piston, Silver, Bronze), Guide, G2 and Code. SRAM says DOT and mineral-oil parts are not compatible, and that the wrong fluid damages all the rubber and plastic parts in a brake. If DOT fluid has gone into a DB8, SRAM says the whole brake, lever and caliper, must be replaced. Only ever put Maxima Mineral Brake Oil in a DB8.

Specifications

Torque figures

SRAM's two documents give different torques for the lever bleed screw: 1.6 N·m (14 in-lb) in the bleed manual and 1.2 N·m (11 in-lb) in the DB8 service manual. Ask SRAM which one applies to your brake.

Replace the brake pads

Before you start: do not touch the pad surface or rotor with oily fingers. Pads that have touched brake oil cannot be cleaned and must be replaced. Wipe oil off a rotor with isopropyl alcohol.

1. Remove the wheel.

2. Pull the e-clip off the pad retainer bolt with needle-nose pliers. Unscrew the retainer bolt (2.5 mm hex) and take out both pads and the H-spring.

3. Measure the old pads. Replace them if pad material plus backing plate is less than 3 mm, or if they have touched oil.

4. Push the pistons back evenly with a plastic tire lever or the SRAM piston press. Do not put oil, brake fluid or grease on the pistons.

5. Fit the new pads with the H-spring between them. Fit the retainer bolt, tighten it to 1.1 N·m (9.7 in-lb) with a torque wrench, and refit the e-clip.

6. Put the pad spacer between the pads, thin side first, and squeeze the lever until the pads touch it. Take it out, then push the thick wedge end between the pads to push them back. Remove it.

7. Refit the wheel, squeeze the lever a few times and spin the wheel to check for rub. Then do the brake test and bed in the new pads.

   From the SRAM DB Brakes Service Manual, Brake Pad Removal, and the Mineral Oil Bleed Manual, Advance the Pistons

DB8 uses SRAM's large pad shape, the same as Code. If you change pad compound (organic to sintered or back), SRAM advises fitting a new rotor too. More on pad changes is on the disc brake pad page.

Align the caliper

1. Check the mount type, rotor size and bolts first. The bolts must be long enough to engage 9–13 mm of thread on post mount, or 5–7 mm on flat mount and thru bolt.

2. IS mount only: fit the IS adapter to the frame or fork and tighten it to 9.5 N·m (84 in-lb) first.

3. Fit the caliper with the bolts loose. Lightly squeeze the lever three times, then hold it on. Snug the bolts lightly and let go of the lever.

4. Look through the caliper and check the pads sit evenly on both sides of the rotor.

5. Squeeze and hold the lever again and tighten both caliper bolts to 9.5 N·m (84 in-lb) with a torque wrench.

6. Spin the wheel. If the pads rub, loosen the bolts and repeat. Recheck alignment after bedding in the pads.

   From the SRAM Mineral Oil Bleed Manual, Disc Brake Caliper Installation

Bleed with Maxima mineral oil

Bleed the DB8 at least every other year, after cutting the hose, or when the lever feels soft and a piston massage has not fixed it. You need the SRAM Mineral Oil bleed kit with its two syringes and the DB8 bleed block (the kits include it), plus Maxima Mineral Brake Oil.

Before you start: wear safety glasses and nitrile gloves and put a pan under the caliper. Use Maxima Mineral Brake Oil only, never DOT 4 or DOT 5.1. Take the pads out before you start and keep oil off the rotor; clean any drips with isopropyl alcohol. Pads that touch oil must be replaced. Dispose of used oil the way your local rules require.

1. The DB8 caliper has a threaded bleed port with a T10 bleed screw, so follow SRAM's "Threaded" steps, not the Bleeding Edge ones.

2. Lever syringe: fit the threaded fitting, fill it about three quarters with Maxima oil, push the air out and close the clamp. Caliper syringe: fit the threaded fitting, put in a small amount of oil and push the air out.

3. Remove the wheel, the e-clip, the pad retainer bolt and the pads. Fit the DB8 bleed block and hold it in with the retainer bolt.

4. Remove the caliper bleed screw (T10) and thread in the caliper syringe.

5. Set the reach so the lever blade is 75–80 mm from the center of the bar (3 mm reach adjuster). Remove the lever bleed screw (T10), wipe any drips with isopropyl alcohol, and thread in the lever syringe.

6. Open the lever syringe clamp. Hold the syringe upright and push oil down gently, stopping before air goes into its tube, until oil fills the caliper syringe. If the oil coming into the caliper syringe is discolored, push all the old oil through and start again with fresh oil in both syringes.

7. Hold the caliper syringe upright and slowly draw back on the lever syringe to pull oil up from the caliper, stopping before air goes into the caliper tube. Repeat this push and pull until only small bubbles come out.

8. Close the lever syringe clamp. Unthread the caliper syringe and refit the caliper bleed screw at 1.6 N·m (14 in-lb).

9. Open the lever syringe clamp and squeeze and release the brake lever 3–5 times. Pull firmly on the lever syringe plunger to make a vacuum, then push to pressurize. Repeat until only a few bubbles come out. Finish with a light push and release to even out the pressure.

10. Close the clamp and remove the lever syringe. Refit the lever bleed screw with a torque driver. SRAM's bleed manual says 1.6 N·m (14 in-lb); the DB8 service manual says 1.2 N·m (11 in-lb) for the lever bleed port screws. Ask SRAM which one applies to your brake. Wipe away any oil with isopropyl alcohol.

11. Remove the retainer bolt and bleed block. Clean the caliper and lever with isopropyl alcohol. Fit the pads and H-spring, then the retainer bolt at 1.1 N·m (9.7 in-lb) and the e-clip.

12. Advance the pistons with the pad spacer as in pad replacement, refit the wheel, check the lever feels firm, and recenter the caliper if needed.

    From the SRAM Mineral Oil MTB Disc Brake Installation, Hose Shortening, and Bleed Manual, Mineral Oil Bleed Procedure

The general method is also on the mineral oil bleed page. Do not use other brands of mineral oil: SRAM has not tested them and does not cover them under warranty.

Test the brake before riding

Before you start: do not ride the bike until the lever is firm and stops well short of the bar.

1. Check the caliper bolts are at 9.5 N·m (84 in-lb), the pad retainer bolt is in with its e-clip, and both bleed screws are fitted.

2. Squeeze the lever hard several times. It should feel firm and stop at the same point every time. If it feels soft or pulls to the bar, bleed it again before riding.

3. Spin the wheel and check for rub. Look for oil on the rotor, caliper and hose fittings. Clean the rotor with isopropyl alcohol if anything touched it.

4. Bed in new pads or rotors: get to a moderate speed and brake firmly down to walking pace, about 20 times. Then from a faster speed brake very firmly to walking pace, about 10 times. Stay seated, never lock the wheels, and let the brakes cool after.

5. Recenter the caliper after bedding in if the pads rub.

   From the SRAM Mineral Oil Bleed Manual, Disc Bed-in Procedure

Bed in somewhere flat and clear of traffic. SRAM warns that the bed-in needs heavy braking and can cause a crash if you lose control.

Fit the lever and set reach

1. MatchMaker X: fit the MMX mount to the shifter and tighten to 3 N·m (27 in-lb). Fit the T-nut into the clamp and put friction paste on the clamp (required on carbon bars).

2. Fit the clamp on the 22.2 mm bar and tighten the clamp bolt to 5.5 N·m (49 in-lb). The clamp must sit flush with the lever body by the bolt head. A small gap on the other side is fine.

3. Turn the 3 mm reach adjuster to bring the blade closer to the bar or move it away.

   From the SRAM Mineral Oil Bleed Manual, Clamp Installation and Reach Adjustment

Shorten the hose

1. Take the wheel off and put a towel under the lever. Pull back the hose boot, loosen the compression nut with an 8 mm flare nut wrench and pull the hose out of the lever. Do not squeeze the lever with the hose off, or oil will come out.

2. Route the hose and hold it to the lever with a gentle bend that still lets the bar turn at least 120 degrees each way. Cut it with a SRAM hydraulic hose cutter.

3. Always fit a new Stealth-a-majig hose barb and a new red SJ compression fitting. Other fittings will not work.

4. Grease the barb threads and thread it in with a T8 until flush. Do not overtighten, because that can damage the hose liner. Thread the compression fitting counter-clockwise (it is reverse threaded) over the barb until flush or just below. Grease the fitting and nut threads.

5. Push the hose firmly into the lever while you thread the nut on by hand, then tighten it to 8 N·m (71 in-lb) and refit the boot.

6. Cutting the hose lets air in, so bleed the brake afterwards.

   From the SRAM Mineral Oil Bleed Manual, Hose Shortening

SRAM's DB service manual also covers rebuilding the caliper pistons and the lever. SRAM says to service the caliper only if the pistons are damaged, to lubricate seals and pistons with Maxima oil only, and to bleed the brake afterwards.

Parts and consumables

Tools

• SRAM Mineral Oil bleed kit (syringes with threaded fittings and bleed blocks, including the DB8 block), and a pad spacer
• T10 Torx (bleed screws, reservoir cap)
• T25 Torx or 5 mm hex (caliper bolts), T25 or 4 mm (clamp)
• 2.5 mm hex key (pad retainer bolt), 3 mm hex key (reach)
• Needle-nose pliers (e-clip)
• Torque wrench and a low-range torque driver
• 8 mm flare nut wrench or crowfoot, T8 Torx, SRAM hydraulic hose cutter (hose work)
• Plastic tire lever or SRAM piston press (00.5318.035.000)
• Isopropyl alcohol, clean rags, nitrile gloves, safety glasses, oil pan

Troubleshooting by symptom

Lever pulls far or feels spongy

Sticky pistons. Do a piston massage: pads out, retainer bolt in, a piston massage spacer or two 1.85 mm rotors between the pistons. Squeeze until the pistons touch, push them back with a plastic tire lever, and repeat until they move freely. Refit the pads and recenter the caliper. Never oil or grease the pistons. If that does not help, bleed the brake. If it is still bad, the caliper needs service.

Lever travel grows as the pads wear

The pistons are not moving out after light use. Wind the reach adjuster all the way out, counting the clicks, pull the lever hard 5 times, then wind the reach back to where it was.

Oil got on the pads or rotor during a bleed

Pads that have touched oil cannot be cleaned. Replace them, and clean the rotor with isopropyl alcohol.

Oil leaking from the lever or caliper

Possible internal wear or damage. The wrong fluid damages all the rubber and plastic parts, and crash damage can affect the blade, pushrod and housing. Stop riding it.

DOT fluid was put in by mistake

SRAM says to replace the whole brake, lever and caliper.

Looks like a leak after a lever rebuild

Water left in the bladder from cleaning can seep out. Dry every part fully before you reassemble.

Reach will not adjust after a lever rebuild

The lever spring is not seated. The short end goes on the blade and the long end on the body.

Want more stopping power

SRAM suggests a bigger rotor, HS2 rotors, a different pad (organic bites harder, sintered lasts longer and works better in the wet) and a proper bed-in.

Related: Bleed mineral oil brakes, Replace disc brake pads, Shimano XT M8100 brakes, SRAM Eagle Transmission