So I’ve been bleeding brakes (Avid, Formula, hope and Shimano) for ages but generally get average results. Good enough to ride but never that rock solid feel that they were when new. I follow the standard manufacturer guides using either a syringe at both ends or syringe and open reservoir for Shimano.

So far to improve the bleed general tips seem to be:
-Draw a vacuum by pulling lightly on syringes (there is some concern about damaging the bladder in the lever)
-Flick/pump the brake lever
-Make sure that calliper and lever are at an angle so that bubbles will float out of the system.

The only way I could get a reasonable bleed out of a set of Formula The One brakes was to draw a vacuum at both ends using a locked off syringe and leave it overnight at an angle so that bubbles would float up into the syringes.

I need to bleed a few sets of Shimano brakes now and am trying to figure out if there are any other techniques to try to get a better bleed. As all out options, I was wondering about proper vacuum filling systems like they seem to use in the factory or maybe make a loop system that pumps fluid through the brake system with a reservoir that will catch air bubbles. Thought I’d ask here for more sensible ideas…

So lets pool some experience for what works best. There is plenty of guidance on how to bleed brakes so they work but any tips/tricks to get a really solid bleed would be great.

SHimano ones just need you to force the fluid up to the receiver funnel, so long as you put enough fluid through to clear all air bubbles and use fresh fluid then you are all good. Mixed fluids can result in poor performance.

DOT fluid systems suffer from seal damage over time which can cause bleed issues, old Elixirs are pretty poor for bleeding. I find it easier to remove the brake system completely and do it off the bike, easier than trying to stretch and undo clips when you are working on some of the extra long bikes these days.

Always remember gravity is your friend. I have a less labour intensive solution for tricky bleeders involving removing the lever, fitting to an old bar from under the bench and clamping them above the bike when bleeding up, or tilting bike in stand and clamping well below when bleeding “down.”

I have also taken (where I have an old set of pad backplates available for the purpose) fitting old pads and closing the calliper on a park pad separator before I start. Some of the multi-piston callipers can be tricky. I then close the lever with a toe strap and use the tool to push fluid out of the calliper bleed nipple. That way you start with an air free calliper before inserting your spacer.

In a busy workshop this is slightly less faff than complete removal and calliper re-alignment, but gives faster bleeds with less fluid. Butlerjamesp is right though, removal is best as a straight and gravity assisted hose always works best.

http://www.pinkbike.com/news/tech-spotlight-5-minute-bubble-bleed-2014.html

I recently rebled my M785 brakes, using the Epic method , plus pulling air out of the caliper with a full cup of fluid at the lever first, and was pretty sure I had them spot on. I store it hanging by its back wheel, and when it’s been hanging a while the rear brake lever is definitely softer than when it’s not hanging. It resolves when riding and both levers become equal in terms of feel and power. Assuming there is still a bit of air in there, where TF is it hiding when I’m doing the bleed? 🙂 I bled them with the forks over the stand, so the bike was I a wheelie position.

Interesting.

I’ve been pretty careful about making sure that bubbles can float out of the lines (I usually take the brakes off of the bike) but I could let them hang completely vertically

I’m wondering whether my biggest error is not flushing the fluid enough. I usually mess around with them for ages pushing fluid back and forth trying to make sure that there was definitely no air in the system. I thought that with mineral oil at least that it didn’t absorb water so would be fine. Definitely try doing a complete flush a few times too.

Cheers for the bubble bleed link JoeG. I did give it a go recently and it definitely improved things when my levers were very inconsistent. Never got them perfect but was quick and relatively painless.

Thegreatape, that sounds like my standard brake bleed experience – think that this time they are going to be perfect and but it turns out they are usable but not amazing.

Only ever had problems with avid brakes I even spunked out over £30 on a “proper”bleed kit with no good results.

I’ve found that the new position of the rear calliper (between the stays) on my Niner is much harder to bleed in situ than others which are on the seat stay.

“DOT fluid systems suffer from seal damage over time which can cause bleed issues,….” ????????????????????????????????

For a brake fluid to be a DOT fluid, and therefore comply with FMVSS116: it must be non-harmful to brake seals and hoses.

DOT “Brake fluid means a liquid designed for use in a motor vehicle hydraulic brake system in which it will contact elastomeric components made of styrene and butadiene rubber (SBR), ethylene and propylene rubber (EPR), polychloroprene (CR) brake hose inner tube stock or natural rubber (NR).”
FMVSS116
http://www.gpo.gov/fdsys/pkg/CFR-2012-title49-vol6/xml/CFR-2012-title49-vol6-sec571-116.xml

Although some older DOT fluids may not have been tested on ethylene propylene diene terpolymer (EPDM) rubber.

But some newer DOT fluids are OK with virtually any type of brake seal eg
DOT 4 LV
http://www.eurol.com/en/37-products/1952-eurol-brakefluid-dot-4-lv.html

http://www.mossmotors.com/SiteGraphics/Pages/brake_fluid/page5.html

http://www.shimano.com/media/techdocs/content/cycle/SI/Deore-XT/SI_0116A/SI-0116A-001-00-Eng_v1_m56577569830746864.pdf

https://www.youtube.com/watch?v=YXmWziLAlBU
https://www.youtube.com/watch?v=aMDit9Irbz4

HOPE
https://www.youtube.com/watch?v=ClMg8B5a9i4

Formula
https://www.youtube.com/watch?v=UepZUB66fGY
https://www.youtube.com/watch?v=1GEk1IaKqRk

Avid
https://www.youtube.com/watch?v=IoaPUw5DliA

I run Shimano XT M785 brakes.

The technique I use is pretty simple and usually produces a rock-solid bleed.

Remove caliper, pump pads out until nearly touching, fit funnel to lever, and syringe to caliper, bleed upwards with plenty of fresh fluid, tap hoses and that while you do it.
Remove funnel and refit port screw.
Gently prise pads apart a little until they slide over the disc(how much you do it is a bit of a game of experience. If the bite is too quick, squeeze the pads out a smidge more, which purges a little fluid from the lever reservoir breather.)

I did this again the other day as it happens. Rock solid brakes, great power, better than factory bleed IME.

The set up after the bleed is also very important to the feel, you want the rotor centred in the caliper not the pads, this gives even pad wear and prevents a spongy feel.

De-gas fluid before bleeding and bleed with pistons slightly out of the caliper.