Author Topic: Best practices for disconnecting and reconnecting hydraulic brakes?  (Read 1421 times)

lantz

I'm swapping internally routed integrated bars, so I need to disconnect the hydraulic hoses from the brifters and pull them out, swap bars, and reinstall.

My first thought is "There must be a way to just plug the hose while I do this so I don't have to completely drain and rebleed the brakes?"

But, I think that's naive? What steps should I take?

1. Flush the system entirely.
2. Remove olive and barb, trim hose.
3. Swap bar/brifter.
4. Install dry hoses.
5. Bleed with new fluid?

Or please god tell me there's an easier way haha.



mirphak

Re: Best practices for disconnecting and reconnecting hydraulic brakes?
« Reply #1 on: August 14, 2024, 02:51:35 PM »
6. Install non-internally routed bars to make your life easier in the future :P .

Jokes apart, I think the procedure you describe is as correct as it can get. Probably if the fluid is relatively new (and particularly if it is mineral, since it is hydrophobic) there is no need to empty the circuit completely. If reusing oil, you can more or less stop it from coming out with a round toothpick ;)

lantz

Re: Best practices for disconnecting and reconnecting hydraulic brakes?
« Reply #2 on: August 14, 2024, 03:37:21 PM »
6. Install non-internally routed bars to make your life easier in the future :P .

Jokes apart, I think the procedure you describe is as correct as it can get. Probably if the fluid is relatively new (and particularly if it is mineral, since it is hydrophobic) there is no need to empty the circuit completely. If reusing oil, you can more or less stop it from coming out with a round toothpick ;)

But why would I make things easy!?

So, maybe that's the route - the brakes only have 100 miles or so on them and the fluid is pretty much brand new. I'll disconnect, plug with a toothpick and hope for the best, then just bleed after re-assembly. Good shit.

frnchy

Re: Best practices for disconnecting and reconnecting hydraulic brakes?
« Reply #3 on: August 14, 2024, 06:58:13 PM »
I always do what you described except I keep the old fluid in the syringe that I sucked it out with - that way I barely have to add any new fluid. This is assuming the old fluid is still good, and it sounds like yours is. This way the lines are empty and it’s easy and not a potential huge mess to get an internal cable routing tool into the line.

lantz

Re: Best practices for disconnecting and reconnecting hydraulic brakes?
« Reply #4 on: August 15, 2024, 11:49:28 AM »
Thanks for the tip Frnchy.

Honestly, that was easy as fuck. I used the toothpick method from Mirphak, made it so I didn't have to fuck with a full flush, re-barbed and then did a quick little bleed for any air I introduced and it was right as rain.

rasch

Re: Best practices for disconnecting and reconnecting hydraulic brakes?
« Reply #5 on: August 16, 2024, 10:50:48 AM »
Why are u installing dry hoses? I think I'd skip that and use the old ones if still usable

stalkersk

Re: Best practices for disconnecting and reconnecting hydraulic brakes?
« Reply #6 on: October 28, 2024, 06:44:49 AM »
Not sure if you are using Sram or Shimano, but you are doing unnecessary steps. Just disconnect route and bleed. Sram nuts are so small you dont need to cut hoses and just reconnect it again. For shimano you are stuck with big nuts so new olive/barb. but again cut as short as possible. Also from my experience I didn't need to bleed Sram brakes even after multiple disconnects.

lantz

Re: Best practices for disconnecting and reconnecting hydraulic brakes?
« Reply #7 on: October 28, 2024, 05:53:23 PM »
Why are u installing dry hoses? I think I'd skip that and use the old ones if still usable

Dry hose was just assuming I drained the hoses before disconnecting and pulling them, but the toothpick trick did a great fucking job.

lantz

Re: Best practices for disconnecting and reconnecting hydraulic brakes?
« Reply #8 on: October 28, 2024, 05:54:24 PM »
Not sure if you are using Sram or Shimano, but you are doing unnecessary steps. Just disconnect route and bleed. Sram nuts are so small you dont need to cut hoses and just reconnect it again. For shimano you are stuck with big nuts so new olive/barb. but again cut as short as possible. Also from my experience I didn't need to bleed Sram brakes even after multiple disconnects.

Yeah, that's what I ended up doing. Shimano system. cut just enough to get below the olive/barb and pinned it with toothpick, ran everything again, good to go. Worked really well, tbh.