Wrench Tip Wednesday: Bleeding Rear Brakes

Wrench Tip Wednesday: Bleeding Rear Brakes

Are you a rear brake rider? Well, I am no professional but I have learned in the past year that if you are in the so called “proper position” on the bike (STANDING ON YOUR TOES) it is impossible to ride your rear brakes. Anyways, back to the point, do you bleed your brake fluid before or after every race? It is not a must but I personally prefer doing preventative maintenance, the risk of losing the rear brakes in a race is not worth it to me.

First step, make sure you have brake fluid on hand. There is a lot of good brands out there varying in prices and boiling points. If you boil your fluid often, I highly recommend Castrol RBF or Motul 660 RBF. Another good brand out there is Maxima RBF.

Next, remove the rear brake reservoir cover. Try to avoid getting any dirt or debris inside. I go ahead and pour brake fluid in and top the reservoir off. Attach a clear piece of tubing to the bleeder nipple (located on the brake caliper), routing the other end into a drain tub. When in a pinch, I will lay down an old towel or rag to catch the fluid vs the tubing. Press down on the brake pedal, then, take your wrench and open the bleeder a ¼ - ½ of a turn. Brake fluid should be traveling through the tube. Close the bleeder. Pump the brake pedal a few times and reopen. NEVER DEPRESS AND RELEASE THE BRAKE PEDAL WITH THE BLEEDER OPEN!!! Pay attention to the color of the fluid coming out. If it is a lot darker than the new fluid keep on bleeding the brakes. There is no sense in keeping any old worn out fluid in there.


Another key tip, do not let the fluid reservoir run out of fluid. If you do, it can result in getting air in your lines. Which can be a big pain in the rear!

Once you are done bleeding the rear brake, check the level of fluid in the reservoir before putting the cover back on. Make sure it is above the minimum and below the maximum. Having too much fluid can also cause the brakes not work as well.

Remember, doing preventative maintenance might result in LESS oh sh!t moments come race day!


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