Bleeding Shimano issues

I’m new to disc brake world.

After bleed the brakes my levers don’t retract really. My brakes are work but the levers don’t snap back.

My brakes rub but I can put my levers forward and the brakes will stop rubbing.

I’ve tried bleeding them twice and not sure what I’m doing wrong, I’ve watched videos and everything. People make it look so easy.

Any advice will help I’m sure it something simple.

It sounds to me as if air got into your system.

To help you, you have to give us a bit more information here: are you talking about a drop bar bike or a mountain bike? (I assume it is the former since mountain bikes have been on disc brakes for close to two decades now, but I want to make sure.) Are you using Shimano’s bleed kit or a third-party bleed kit? What bike do you have? Do you use a work stand?

It actually is, especially on flatbar bikes. On road bikes it can be trickier, because the hose routing can be a bit more involved and getting all the air bubbles out is bit harder.

I have road bike drop bars. I’m using bleed kit from bleed zone.

Have you seen the Park Tool video? It’s super helpful and covers the process pretty well.

few things come to mind…

Possibly incomplete bleed. Id re-do the lever bleed and see if that helps. Try and get the bike vertical if thats reasonable so the bleed funnel is as high north as possible
Are the pistons dirty? can cause friction on the seal that may slow down retraction

+1, one of the most common issues I’ve experienced with disc brakes from all brands.

I’ll usually:

  1. Wash the bike first, let dry
  2. Remove wheel and pads
  3. Clean the entire caliper assembly with alcohol
  4. Carefully pull the levers to push the pistons out slightly
  5. Clean pistons with brake fluid - helps dissolve dried up old fluid and also lubricates pistons
  6. Push the pistons back in with pad tool
  7. Clean again with alcohol
  8. Reassemble.


Thanks for all the advice everyone.

So if the bleed is incomplete what’s should I do, syringe pushing fluid through or just cup bleed again? I’ve done this 2-3 times already for both methods.

Do the lever not retact because I have that much air in the system?

The fluid condition vis a vis a good or bad bleed shouldn’t really have that much to do with pad retraction. (But see below) Could be the pistons were dirty when you retracted them and now the seals are sticking a bit. Or, if you removed the pads, are you sure you put the spring in right and otherwise did the pad reinstall correctly?

On the other hand if you don’t retract the Pistons before you do the bleed or otherwise add additional fluid to the system, you can end up in a situation where The pistons and pads are too far out and have no room to retract because of the excess fluid in the system This may make it feel like the pads are not retracting

Reading to your reply and all, one possibility is that you did not have enough oil in the reservoir and you sucked in air. Another factor is that cable routing in drop bar bikes tends to be more complicated. The hydraulic hoses make more twists and turns, so you might have to tilt the bike frame a few times on the bike stand. (A bike stand makes this procedure much easier!)

Also, I second what the @QuittingBikes wrote: make sure your entire bike (including brakes) is clean. I usually service my hydraulic brakes after I gave my bikes a thorough wash and checked things like my bottom bracket, chain, etc.

Clean the inside of your brakes and make sure the pistons do not have any grime or debris on them. Shimano pistons are made of white ceramic, so that’s easy to see. Use isopropanol and shop towels. Kitchen towels can be used, but they tear easily, especially when wet, and may leave fibers behind.

All of this sounds very complicated, but it is not. I think you just got a bit unlucky the first time around.

Yeah, this is starting to get frustrating. I’m to the point of just going to shop letting them deal with it.

I saw this video and thought about trying this.

Did you use a mineral based oil for your Shimano brakes? If you used a DOT based brake fluid then the seals in the master cylinder will swell meaning your levers will jam.

If you have done this then you need to fully strip the system, clean pistons and master cylinder with alcohol and replace the hoses. Just a small amount of cross contamination will continue to ruin the seals.

Using mineral oil in DOT brake systems also result in similar failure, with seals likely to crumble.