Sometimes riders notice that their brakes aren't up to snuff but they don’t know what to do.
Soft or spongy brakes are a serious matter. It’s vital to be able to slow or stop quickly.
Check the brake pads first. There may be an external indicator that you can look at to give you an indication of wear. But it’s a good idea to take the pads out to inspect them, even if that means removing the caliper.
Thoroughly inspect the master cylinder, each caliper and all the brake lines for evidence of leaks. If the brake pads are good and there don’t appear to be any leaks, then the most common reason for a soft or spongy brake feel is air bubbles in the system.
Take a screwdriver and remove the screws that hold down the master cylinder cover.
Remove the cover and rubber diaphragm and check not just the fluid level but the condition of the fluid. It should be clear and free of any debris. Brake fluid that is discolored should be thoroughly flushed out and the system filled with fresh fluid.
Refill only with the fluid recommended by the manufacturer. Many times the fluid type is stamped on the master cylinder cover.
Use a vacuum brake bleeder, if possible, to simplify the job of bleeding the brakes. If you don’t have one you can buy one. It will come in handy more times than you think.
But you can bleed the brakes manually if you have some help.
You will need to bleed each brake caliper separately. Start with the caliper that is furthest from the master cylinder. Attach the clear vacuum hose from the bleed valve to the pump reservoir and another hose from the reservoir to the vacuum pump.
Pump the brake bleeder and loosen the bleed valve. The old fluid should flow. If it doesn’t, lightly operate the brake lever because you could have a clog in the line or valve.
If you see any bubbles, no matter how small, you have probably solved your problem. Keep an eye on the fluid level in the master cylinder while doing all this because the fluid can flow pretty quickly. Keep the master cylinder full.
Then close the bleed valve. Repeat for the next caliper.
Be sure to clean and replace the rubber diaphragm and cover on the master cylinder and tighten the screws. Be careful because spilled brake fluid can damage paint.
Pump the brake lever until the pads touch the rotors.
Take a slow test ride to be sure the brakes are working properly. Now you’re ready to ride.