How to Bleed and Set Up Your Bike Brakes
Firm lever, no rub, full stopping power. Get the fluid right.
A spongy lever, wandering bite point, or rubbing rotor means it is time to bleed and set your brakes. The single most important thing: use the correct fluid — Shimano mineral oil and SRAM DOT are NOT interchangeable, and the wrong one destroys the seals.
Shimano
Mineral oil, funnel bleed. Forgiving and clean — the workshop favourite.
Correct fluid — do not substitute
Shimano mineral oil (red/low-viscosity). Never DOT.
Mineral oil and DOT are not interchangeable — the wrong fluid destroys the seals.
Torque specs
| Caliper mount bolts | 6–8 N·m |
|---|---|
| Centerlock lockring | 40 N·m |
| Banjo bolt | 5–7 N·m |
Manufacturer-claimed — always confirm against your model manual.
Video walk-throughs
How to bleed Shimano brakes (funnel method)
Park Tool
Shimano brake bleed at home
GMBN Tech
Opens a YouTube search — we link out rather than embed unverified videos.
Manuals & documents
Further reading
Mechanic's tips
- Use ONLY Shimano mineral oil.
- The funnel + one-way lever bleed clears air fast.
- DOT and mineral oil are NOT interchangeable — the wrong fluid swells and destroys the seals.
- DOT fluid is corrosive: keep it off paint, skin and eyes; wear gloves + glasses.
- Any oil on pads or rotor kills braking — clean with isopropyl or replace contaminated pads.
Tools you'll need
Brand-specific bleed kit
Funnel or syringes to match
Correct fluid
Mineral OR DOT — never mix
2.5 mm hex + torque wrench
Bleed ports + caliper bolts
Isopropyl alcohol + rag
Clean spills off pads/rotor
Gloves + eye protection
DOT fluid is corrosive
Step by step
- 1
Fit the bleed spacer
Remove pads, push pistons back, fit the bleed block.
- 2
Attach the kit
Funnel at the lever or syringes at both ends — per system.
- 3
Push fluid through
Move fluid lever↔caliper to carry air out of the system.
- 4
Purge air
Tap the hose/caliper, work the lever, chase every bubble.
- 5
Set the bite point
Close bleed ports; lever should be firm at your preferred reach.
- 6
Align the caliper
Squeeze the lever, snug the mount bolts so pads clear the rotor.
- 7
Bed in the pads
Accelerate + brake firmly 15–20× to transfer pad material.
- 8
Check for rub
Spin the wheel; fine-tune caliper position until silent.
Frequently asked
Can I mix mineral oil and DOT fluid? +
No — never. Mineral oil (Shimano, Magura, most TRP) and DOT fluid (SRAM, Hope) attack each other's seals. Even a small cross-contamination swells the caliper and lever seals and the brake will need a full rebuild. Always check the fluid stamped on your lever or caliper before you start.
How do I know my brakes actually need a bleed? +
A lever that pulls to the bar (spongy or getting softer over weeks), a bite point that keeps creeping closer to the grip, or visible fluid weeping at the lever or caliper are the classic signs air or a fluid leak has got into the system. A rubbing rotor with no lever softness is usually just caliper alignment, not a bleed.
Why is my rotor rubbing after I fitted new pads? +
New pads are thicker than worn ones, so the caliper needs to be re-centred. Loosen the two caliper mount bolts, squeeze the lever firmly to self-centre the caliper on the rotor, then torque the bolts while still holding the lever.
Do I need to bed in new pads and rotors? +
Yes — skipping bed-in is the #1 reason new brakes feel weak. Accelerate to a moderate speed and brake hard (without locking up) 15–20 times per wheel, letting the brake cool between efforts. This transfers a thin, even layer of pad material onto the rotor and roughly doubles peak stopping power.
How we source this
- Steps and standards are drawn from Park Tool's public repair guides plus each manufacturer's own bleed and service manuals — cross-checked, not copied from a single source.
- Torque figures are manufacturer-claimed — always confirm against your model's manual before applying a torque wrench, especially on carbon calipers or levers.
- Fluid type (mineral vs DOT) is stated per brand for the models we cover; some brands changed fluid type across generations, so always confirm what is stamped on your specific lever/caliper before opening the system.
- Video links point to real, named creators (Park Tool, GMBN Tech, brand channels) for a title/channel search — we never fabricate a video ID or embed an unverified clip.