Updated: Jul 4, 2019
Owning a motorbike is a responsibility that comes with its own requirement of skills. You will learn how to carry out many tasks that you had not been able to carry out before. One of these tasks is the big, daunting world of repairs. Brace yourself
for the repair of your brake calipers – a job that all must be equipped to do when it comes to owning your own motorbike. Do not be daunted by the task as it is not a big one, however it is a crucial one.
We at Siima MotoWear have done some serious research and give you some nice inside on how to rebuild your brake caliper.
A caliper is the most essential cog in the disc brake system which facilitates your ability to stop when you need to. When force is applied onto the brake pedal, brake fluid flows into the calipers from the master cylinder. Brake fluid is the reason your ride stops – it applies pressure onto the piston inside the caliper, using the brake pads to push against the rotors to stop your vehicle.
You will need to be equipped with the following to be able to carry out maintenance of your calipers:
Wrenches and sockets
1500 and 800 wet and dry sand paper
Brake piston removal tool
Specially formulated grease for brakes
You can try out the simpler method before you go ahead and work through the disassembly by using brake cleaner while the caliper is still on the break. Start by pumping the brake level until the wheel is locked. Maintain pressure on the lever to ensure that the pistons are extended as required under normal working.
Displace the dirt by spraying the brake cleaner on the exterior of the pistons. Follow this by releasing the brakes and try grabbing the lever to check for firmness. Repeat the cleaning process three to four times in order to see if the lever is returned to optimum.
In case you must disassemble the caliper to resolve the issue and cleaning does not do the trick, follow this method: you must start by removing the pads from the caliper – remove the pins that hold the pads in place, the pad pin, and once you have managed that, you can also remove the brake pads. Try to remember the positions of the anti-rattle shim found beneath the pads, or take pictures, in order to be able to place them back where they were found once you are done.
You need to isolate one piston at a time and work with it while the others remain clamped together. Secure the pistons together using a small plate, and release one piston a time. With only one piston free and the others held (the other three, five, or just one depend on your bike as the number of piston varies), try pumping the lever and observe the result in order to see if the piston is stuck to the seal. If it follows the back and forth movement of the brake level, then it is stuck to the seal.
If you find the piston to be somewhat out of the caliper, you can fix it by spraying brake cleaner around the piston to displace any dust or dirt. Following that, you can apply pressure using a clamp or your finger to push the piston entirely into the caliper. The next step is to pump the lever in order to move out the piston for one fourth of an inch. If the piston is successfully moved out this far without being pushed back into the caliper, it is fixed, if it manages to stay in this position for fifteen seconds.
However, if it is being sucked back into the caliper, you could try lubricating the exposed surface of the piston using brake fluid to reduce the friction between the metal piston and the rubber seal. Set it in place by pushing the piston all the way back into the piston. Test this by pumping the brake level and seeing if the piston pushes out to one fourth of an inch and remains in place. If this is achieved, push the piston back into the caliper.
You need to repeat this process by removing the clamp from the other pistons that were clamped while you isolated one. You must work the other remaining pistons in the same way until they exhibit the same behavior when tested: push out to one fourth of an inch by pumping the break lever and observing whether the position is maintained.
Regulate the level of hydraulic fluid in the reservoir as pressing the pistons back into the caliper may lead to accidentally overflowing the hydraulic fluid. You must make sure that the repair process does not introduce air into the system which will require a repair system of its own.
When the last piston is tested and released, let go of all the clamps and pump the brake lever. You will know your mission has been successful when the pistons move outward and maintain their position.
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