Find out whether the lever or the caliper is sticking
A brake that does not return can have a problem at the lever, in the cable or hose, or at the caliper. Work out which end is sticking before taking anything apart.
- Squeeze and release the lever with the wheel off the ground. Does the lever itself snap back?
- Do the pads stay against the rim or rotor even though the lever returned?
- Does it happen on only one side of a rim brake?
Do not ride with a brake that drags or stays partly applied. It generates heat, wears pads quickly, and can affect braking.
The cable test
For cable brakes, this simple test separates cable problems from caliper problems.
- Release the cable from the caliper (for V-brakes, unhook the noodle or cable end; for side-pull calipers, use the quick release or loosen the cable pinch).
- Squeeze the brake arms by hand and let go.
- If the arms snap back freely, the problem is in the cable, housing or lever. If they are sluggish, the problem is at the brake itself.
Cable and housing
Dirt, rust, or kinks inside the housing create friction. Signs include a lever that feels gritty or slow.
- Check the housing for kinks and cracks, especially at tight bends.
- Slide the inner cable out and inspect it for rust or fraying.
- Clean and lightly lubricate the inner cable if it is in good shape, or replace the cable and housing if it is rusty or damaged.
Replacement is often the simplest, most reliable fix, and cable housing is inexpensive.
Pivots and springs on rim brakes
If the brake sticks even with the cable disconnected, look at the pivots.
- Remove the brake arms from their posts and clean the posts and the insides of the arms.
- Apply a light coat of grease to the pivots, keeping it away from the pads and rims.
- Check that mounting nuts are not overtightened. On some side-pull calipers, a pivot nut that is too tight can make the arms bind.
- On V-brakes, check the spring on each arm. Some have a small tension screw, and some let you move the spring to a different hole on the post for more return force. Check your brake’s instructions.
Springs that have lost tension or are damaged are best replaced, or the brake arms replaced, rather than bent.
Lever pivot and lever return
If the lever itself returns slowly with the cable disconnected, its pivot may be dry or dirty. Clean around the pivot and apply a small amount of suitable lubricant, wiping off any excess so none reaches the braking surfaces. Lever return springs inside the lever body can also fail, and in that case replacing the lever is usually necessary.
Disc brakes: pistons that will not retract
On hydraulic disc brakes, the pistons sit in the caliper and need to move freely. If they stick, the pads can stay in contact with the rotor.
- Remove the wheel and pads and gently push the pistons back with a clean plastic tool. Avoid scratching them.
- Clean around the exposed piston with a lint-free cloth and a brake-safe cleaner such as isopropyl alcohol, keeping it away from the pads.
- If the pistons feel stiff or sticky, the brake may need servicing or a bleed. Details vary between brands, so use the manufacturer’s instructions or see a shop.
Contaminated or stuck pistons can also cause weak braking, which is explored in disc brakes with no stopping power.
Why a caliper will not push back in
If you are trying to fit a wheel and the pads are too close together, the pistons may have been pushed out, often because the lever was squeezed while the wheel was out. Push them back gently with a plastic tool, and do not use a sharp metal tool against the pistons or pads. If they refuse to move, stop and have the brake serviced rather than forcing them.
Once the wheel is back in, pump the lever until it firms up, then check for rub using the steps in fixing front brake rub.
When not to ride
Stop riding and get help if the brake does not release fully, there is any fluid leak, the cable is frayed, or the lever travels far before the brake engages. For general cable take-up and release adjustments, see how to adjust rear bike brakes.
FAQ
Why are my brake pads not springing back?
Common causes are a sticky cable or housing, dirty or binding pivots, weak springs, or stuck hydraulic pistons. The cable test helps tell which.
Why is my brake lever not bouncing back?
Check cable friction first, then the lever pivot and return spring.
Why are my bike brake pistons not retracting properly?
Dirt, residue, or pistons pushed out of position can cause this. Gentle cleaning and resetting may help, but sticky pistons often need servicing.