Dan’s Tech Centre: How to bleed Avid brakes.

So here we are, another tutorial coming your way from our Office Padowan Dan…

For the past year I have been running the fantastic Shimano SLX brake, with no mechanical issues except a bleed and new pads mid season, I was happy with the performance and used to the unique Shimano lever feel. However, I felt a change was in order, so when some Avid Codes caught my eye I jumped at the chance to get them fitted; my trusty Specialized Demo 8 was in for a nice surprise being kitted out with the best SRAM had to offer.

With the Codes fitted it was time to trim the factory length hoses, so I thought I may as well give them a bleed and give you guys the knowledge to do it yourself.

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So here are the tool’s you will need:

2 Avid compatible syringes
Dot 5.1 brake fluid
Bleed block
Protective gloves (pref. nitrile, in this case latex)
Toe strap
T10 torx
4mm allen key
2.5mm allen key

Rag (not pictured)

Step Uno

Prepare Your Syringes.
Fill one syringe half full with dot 5.1 fluid, fill the other syringe quarter full.

Now you need to take any air out of the syringe, so when you come to bleed the brake you don’t insert any unwanted air. To do this hold each syringe with the tip pointed up and the tap the side of the syringe with your finger to bring any air bubbles to the top. Place your rag around the tip and slowly push the air bubbles out of the syringe.

Once both syringes are done you are now ready to bleed the sytem.

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Prepare The System.

Remove the wheel from your bike, remove the brake pads and spreader clip from the caliper, make sure to place your pads and spreader clip somewhere safe so you don’t lose them, now insert the appropriate bleed block. This will help prevent system overfill and also dot fluid from contaminating your brake pads.

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Using your T10 torx remove the caliper bleed port screw, again making sure to place the tiny screw somewhere safe.

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Now insert the half full syringe into the caliper bleed port. The caliper is now ready.

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Depending on which Avid lever you have there are different procedures to get your lever ready.

For any lever with pad contact adjust and a rotating bleed port screw, rotate the adjuster in the direction opposite the arrow until it stops, then rotate the adjuster back just enough to place the bleed screw at its highest point.

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Using your 4mm allen key loosen off your lever and rotate it so that its parallel to the ground. Using your T10 torx unscrew the lever bleed screw, now insert the quarter filled syringe into the lever bleed port. Your lever is now ready.

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Step Deux.

Bleed The System

Hold both syringes upright. Gently push on the caliper syringe plunger to move fluid from the caliper syringe into the lever syringe until the lever syringe has increased to 1/2 full and the caliper syringe is decreased to 1/4 full. You should see bubbles flow into the lever syringe. Close the lever syringe clamp.

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IMG_2813Pull the brake lever all the way to the bar with your finger and hold it there until instructed to release the lever in a later step. If you don’t want to hold the lever with your finger, use a toe strap or zip tie, or even a helpful assistant; personally for me using a toe strap is the easiest way because they are easy to take on and off.

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Pull out on the caliper syringe plunger to create a vacuum, then gently push in on the plunger to pressurize the system. Repeat this procedure several times, until large bubbles stop coming out, do not pull out too hard on the plunger or you will suck air past the the plunger seal into the fluid and create more bubbles while stopping any air coming out of the caliper.

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Once the large bubbles have stopped, apply a small amount of pressure on the syringe plunger and slowly let the pressure extend the brake lever you have been holding with the toe strap. Close the clamp on the caliper syringe, then remove the syringe from the caliper and re-install the bleed port screw. Using water, spray some onto the caliper removing any excess dot fluid, then using your rag wipe away any excess fluid of any kind. Re-insert the pads and pad screw.

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Step Drei.

Bleed The Lever.

Open the clamp on the lever syringe. Pull out on the syringe plunger to create a vacuum, then gently push in on the plunger to pressurize the system. Squeeze and release the brake lever ten times, allowing the lever to snap back to its starting position after squeezing (this helps break loose any remaining bubbles). Repeat this procedure several times, until large bubbles stop coming out of the lever. Once the large bubbles at the lever have stopped, apply a small amount of pressure on the syringe plunger. Remove the syringe and re-install the bleed port screw. Using water and your rag clean the lever of any excess dot fluid.

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Your Avid brake is now ready to ride; re-insert your wheel, set up your brakes and then go out and shred it.

Thanks for tuning in to the second of my tech tutorials, I hope I have helped you out and also saved you a bit of cash in the process. If there are any tutorials you would like me to do please comment below and I will try my best to help you out.

Working on your bike is as simple as peas.

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