Why is there no pressure in brakes after leak?

Question

I made a mistake when trying to align the caliper to correct for the disc rubbing against the brake pads. Instead of unscrewing the bolts mounting the caliper body to allow adjustment, I unscrewed the bolts holding the caliper together - loosening the caliper body itself, but not entirely taking it apart (as you can see I'm very new to this - please be gentle).

Not yet realising my mistake I pumped the brakes a few times to align the caliper, which caused brake fluid to leak. I subsequently tightened the bolts, and tested the brake which now held no pressure.

I am guessing the issue now is that I've either drained the fluid or introduced air to the system. However, given the issues I caused before I wanted to seek advice before botching it any further!

Any advice on what might now be the issue, and how to diagnose then fix it, would be hugely appreciated!

It is a (no longer functioning) Avid Elixir 1 disc brake.

Answer 1

If fluid was removed, it means there's air there now. If it was a lot of fluid, it means there's a lot of air in there. Air being easily compressible, enough air in brake system causes brakes to not work.

You need to bleed your brakes. There's no way around that. I'm sure you can find instructions easily online. Usually, the basic procedure is:

1. You fill a syringe with brake fluid and connect it to the bleed port
2. You put a container above the master cylinder, fitted with a screw, before that you need to remove the screw cap
3. You undo the bleeding screw at the caliper
4. You push brake fluid into the system
5. You re-do the bleeding screw at the caliper
6. You remove the syringe
7. You seal the container above the master cylinder, remove it, and reattach the screw cap

Now your brakes should work fine! The container and the syringe are part of the bleed kit. Be sure to use the correct type of brake fluid for your system, if you use incorrect the seals may fail.