Avid disc brakes might just be the most commonly seen hydraulic disc brake systems these days. They come OEM on many of todays mountain bikes, and are easy after market sells as well due to the great performance-to-price ratio. Although I have my complaints about some of these brakes (As I do with almost every brand of brake!) I greatly appreciate one thing:
Avid has the cleanest bleeding system on the market. This is a good thing, since they seem to need bleeding more often than some others.
By following Avid’s Bleed Instructions, you can easily get every last bubble out of the line, the caliper, and the lever body. The beautiful part about these brakes is that unless you have had the system apart to service or replace the caliper or the hose, you rarely ever need to perform the entire bleed procedure. The air easily moves up the system and collects in the master cylinder reservoir. The air can then be easily removed by quickly bleeding the lever.
The procedure for an Avid brake lever bleed is as follows: (For Juicy, Elixir and Code brakes)
Prepare the lever. If your brake lever features pad contact adjustment, be sure to turn this all the way to the OUT position. Usually this means turning it in the direction opposite the arrow. If the direction is no longer visible on your brake, you should turn it in the direction that makes the brake pads contact the rotor soonest (or makes the brake feel firmest.)
- Position the lever. Position the lever blade in a way that puts the bleed port the highest. For Juicy brakes and old Codes this would mean
positioning the lever in a vertical position, with the lever blade pointing towards the ground. For some Elixir brakes and newer Codes it means turning the pad contact adjustment until the bleed port is pointing up.
- Bleed. Fill an Avid bleed syringe about 1/4 full with DOT 5.1 fluid. Remove the bleed port and thread in the syringe. Gently pull back on the syringe until you see air bubbles move up the line and into the syringe. Gently push fluid back into the brake and then pull back on the syringe again. The process basically requires that you
repeat this action of pulling air out of the lever and pushing fluid in until air bubbles stop coming out of the lever. It is important that you don’t pull back to hard on the syringe, as you can suck air past the seals and into the system. You may find it helps to squeeze and release the lever a few times during the process to help loosen any air bubbles trapped in the master cylinder. It is also important that your Avid bleed kit is in good condition as a leaky syringe or bleed fitting will make getting a good vacuum action difficult.
- Finish bleeding and clean up. When bleeding Juicy brakes or the older Code brakes (Pre-2011), when you’ve succeeded in removing all the air from the lever body, rotate the lever body up until it is horizontal with the ground before removing the syringe and replacing the bleed port screw. For Elixir brakes and the new Codes, just detach the syringe and replace the screw. If you did everything right, some corrosive DOT fluid will have leaked out of the lever body and will need to be cleaned up using some rubbing alcohol and a rag.
That’s it! Using this procedure, you can keep your Avid brakes feeling tight and responsive with the most minimal maintenance time.
How do I know when my Avid brakes need bleeding?
To find out quickly whether or not you need to bleed your avid brakes, perform this easy test:
Pick your bike up by the handlebars and stand it on the back wheel with the front wheel and brake lever blades pointing up. Squeeze both brake levers repeatedly. Do it at least ten times. If there is any air in the system, it will work its way into the master cylinder and the lever will pull closer to the bar. If after thirty seconds of pulling your brakes with the levers pointing up into the air the levers still feel fine, then you can be pretty sure that air is not trapped in the lever and probably doesn’t need to be bled. If on the other hand, the lever pulls to the bars, perform a lever bleed as described above.