Mountain Bike Reviews Forum banner
1 - 11 of 11 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter · #1 ·
I just bought Shimano hydraulic brakes (Bl-m445) and when I got everything done cutting the line put the brass pieces on. shoved the line into the brake. As I was bleeding the brakes it started to leak out of the fitting on the hose where the brass is. Im thinking the brass crimp piece didn't set right. but this is my first year riding and im new to everything.
 

·
Magically Delicious
Joined
·
12,499 Posts
Doing your own brakes is easy. Just take some time and understand what you are doing and do it right. Your line nut was not properly torqued enough to set, seal and compress the olive to the line. Don't let a minor problem prevent you from learning to do this on your own. Go to the brake forum and you'll find plenty on this subject.
 

·
Magically Delicious
Joined
·
12,499 Posts
Check out some of these:

http://forums.mtbr.com/brake-time/shortening-hoses-899237.html

http://forums.mtbr.com/brake-time/shortening-shimano-xt-hoses-771412.html

To summarize one of my earlier posts:

Bleeding your brakes, especially Shimano's is easy. And yes, you can shorten the brake lines without having to bleed if done carefully. But bleeding this isn't difficult if you induce some air into the system. My steps here are for shortening the brake lines on the XT M-785's, but I don't think there's any significant difference if any.

When line is opened, air is introduced near the master cylinder. By expanding the brake pucks, we can force bleed any remaining air from cut and reinstalled line up into master cylinder by compressing pucks back into caliper.

Remove rubber boot and loosen 8mm brake line at each master cylinder.

Separate brake line from master cylinder and measure for proper length of brake line from caliper to master cylinder. Be careful to allow for unrestricted full front wheel side-to-side movement.

Mark line for cut and carefully cut with cable cutter. Fluid will come out, so be ready for it.

Remember…measure twice, cut once.

After cutting line, you might want to slightly enlarge the opening with an awl to ease insertion of connector insert.

Slip compressible brass olive over line.

Place clamping blocks on line and secure with vice or vice grips to stabilize while driving insertion connector in line opening

Reinsert shortened brake lines back into the appropriate master cylinders and torque to 45 - 60 in. lbs.

To properly torque, you need an 8mm crows foot and perform the calculation for proper torque.

I incorporated the calibrated wrist technique.

Return to calipers and carefully press brake pucks back into calipers until flush with caliper body so that you can re-install brake pads. This will force any air introduced into the line from the line removal back into the master cylinder reservoir thus eliminating the need to bleed the brakes.
 

·
Magically Delicious
Joined
·
12,499 Posts
Only problem Im having is the hose leaking.
There's not too much that you can do to really mess that part of the install up. Assuming that you installed the barb correctly and placed an olive on the hose, the only part that seems missing is a correct torque. Truth be told...I have used a crows foot and performed the correct calculation in using a crows foot and found it to not be adequate. I have had to slightly over-torque to get the line to properly seal. This is dangerous advice to suggest torqueing beyond the recommended manufactures advice (especially on an aluminum component). But I did and it corrected the leak. Proceed at your own risk.
 

·
Magically Delicious
Joined
·
12,499 Posts
Okay ill try that I was just scared to over tighten it and break it. so should I buy a torque wrench to be 100% that the torque is right?
Again, as I said above, you will need a Crows foot and to do the calculations to determine the proper torque using an extension. But again, as stated, I still had to apply a slightly greater torque than specified to get the olive to seal on the line. And yes, my extension calculations were correct. It's really a simple process, but given your trepidation, perhaps you should take it to your LBS.

It'll come to a (sort of) hard stop, as long as you keep the line flush while tightening. When it stops reasonably tight, the job is done.
Take caution with this statement as well as mine. Hatake's statement is likely acceptable to someone with wrenching experience, but remember we're advising someone who has little or no experience and finding that elusive "reasonably tight" sweet spot. If you have reservations, take it to your LBS and get them to show you what they are doing as to learn the tricks.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #11 ·
I know what im doing when it comes to cars. Just new to the bike thing. Since ive already tried to tighten it down and the crush ring has been tighten to the hose would I be able to back the screw out and try again? Or do I have to cut the hose and start over again?
 
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top