Bleed Your Motor Bike's Brakes No.2
As the previous article states "Usually when working on a vehicle it is best to follow the manual; however, conventional information about bleeding the brakes by using a plastic tube and pumping the fluid into a jar may not work as they suggest". This traditional method causes the air to be constantly be trapped in the vertical hose. we are trying to push it down and it wants to rise. This second method is not any better than the first article just another approach.
Contents
Steps
- Make certain the bike is stable.
- Remove the whole caliper and use a thin piece of wood or metal to replace the disk in between the brake pads. This must be at least as thick as the disk, if thicker push the pads apart. careful the brake fluid does not over run the master cylinder reservoir.
- Use a piece of wire though the caliper mounting holes to allow it to be hung from the handle bars or similar. NEVER ALLOW THE CALIPER TO HAND ON THE HOSE. YOU CAN INTERNALLY TEAR THE HOSES AND GUESS WHAT! WHEN YOU REALLY NEED YOUR BRAKES THEY FAIL.
- Pump the brake lever to clamp the pads onto the spacer. A bit of electrical tap is also good to ensure it does not fall out.
- Try sucking out the old oil in the reservoir (not right to the bottom) and put in new oil. This allows the oil to be changed at the same time. Most time the air in the brakes is caused by the breakdown of the fluid due to high temperature, regular changing will stop this and stop corrosion.
- Place a small hose onto the bleed screw nipple and into a tin can.
- Select a good fitting ring spanner for the bleed screw.
- Lift the brake caliper above the master cylinder and reservoir so the brake hose is straight not sagging. (note you can also do the same by lowering the master cylinder to below the caliper.
- Get a second person to apply the brake and hold on.
- Crack open the caliper bleed valve and close before the other person takes the brake lever off.
- Repeat the bleed process as above until new oil comes out of the wheel cylinder and no air is present.
- Careful to not allow the reservoir to become less than 1/4 full or you may suck in air and you will need to start all over again.
- Replace the brake caliper and tension bolts correctly.
- Pump the brakes to get ready for the road/dirt/track and ensure no leaks.
Tips
- It is better to do this with two people but the second person to operate the breaks does not need to be technical.
- If you are racing or using you brakes to their extreme, Use a new un-opened container of brake fluid as it is hygroscopic and will absorb water, Not a big issue for normal ridding and regular fluid changes.
- Careful to not allow the reservoir to become less than 1/4 full or you may suck in air and you will need to start all over again.
- Ensure you use the correct fluid, some modern fluids are not compatible with the old.
- Don’t get the brake fluid on your paint unless you want to remove the paint or its shine.
- Not recommended but!!!! if you do get brake fluid on the disk use brake cleaner or methane to remove. If it's on the pads you can remove the excess as previous and than cover in chalk or baby powder and bake or 110deg'C to absorb the fluid out of the pads. But they are never the same again so replace as soon as possible. (Works great for cars as well but you also have 3 other sets of pads)
Warnings
- Ensure the brake works before riding and be careful for the first 10 brake uses.
- NEVER ALLOW THE CALIPER TO HANG ON THE HOSE. YOU CAN INTERNALLY TEAR THE HOSE AND GUESS WHAT! WHEN YOU REALLY NEED YOUR BRAKES THEY FAIL.
- DON'T ALLOW THE BRAKE FLUID TO GET ON THE BREAK PADS OR THE DISK.
