Someone School Me on Bleeding Hydraulic Brakes
#1
Senior Member
Thread Starter
Join Date: Oct 2016
Location: San Mateo,Ca.
Posts: 3,984
Bikes: TRIMMED DOWN THE HERD
Mentioned: 46 Post(s)
Tagged: 0 Thread(s)
Quoted: 1090 Post(s)
Liked 935 Times
in
600 Posts
Someone School Me on Bleeding Hydraulic Brakes
I'm about to do this for my mtb. Brakes are Avid Elixir 5. Have watched some videos on YouTube and have read up a bit on it but I'd also like to hear from first hand experience. I have the bleed kit on order. New pads going in too. Tips and suggestions are appreciated.
Thanks much!
Thanks much!
#4
Non omnino gravis
#5
Full Member
Do not install the pads until you've bled the brakes. Use the orange spacer if it's Shimano.
#6
Senior Member
Beware that the design of Elixirs is both very sensitive to good bleeding and very prone to failed seals in the master cylinder. If your brake feels like there's too much fluid in it and the pads run too close to the rotor, and/or you hear a squishing sound in the master cylinder when you actuate the lever, don't bother rebuilding the levers: throw those crappy Elixirs into the trash where the belong and buy pretty much literally anything else (but realistically entry level Shimano brakes). If you're concerned about the master cylinder seals being damaged, I recommend avoiding pulling a vacuum on the lever syringe even though it's part of the standard bleed instructions as it can pull air past the master cylinder seals and into the lever.
If the levers are actually in reasonably good condition, the bleed instructions are pretty easy and posted on Sram's site and also are included with the bleed kit. One thing in general is that it's good form to clean the pistons well before pressing them in.
Bleed proceedure is basically fill 1 syringe 1/2 full, another 1/4 full. Degass 1/2 full syringe by closing off the line either with the little line crimp or with your gloved finger and pull moderately until air bubbles form, and alternate with compressing it. Shake and hit it and generally get as much air out as you can but do not obsess over this step--you will never get to the point where you cannot form more bubbles. Pull brake pads, clean pistons, then push pistons in before installing bleed block. Attach 1/2 full syringe to caliper bleed port and 1/4 full syringe to lever bleed port. Push fluid up until caliper syringe is almost empty--you should see bubbles. Close lever bleed line by using the line crimp or by reinstalling the bleed port screw. Depress lever and hold it in place while alternating gently pulling on caliper syringe and gently pressing on it to try to get any air out. Hold lever as you push syringe and let lever out again. Create vacuum and pressure at lever syringe to remove bubbles. Be very gentle if (or seriously just push fluid up from caliper and call it a day) if you are suspicious of the conditions of the master cylinder. Clean the crap out of everything with isopropyl alcohol . Wash your hands real good at the end.
If the levers are actually in reasonably good condition, the bleed instructions are pretty easy and posted on Sram's site and also are included with the bleed kit. One thing in general is that it's good form to clean the pistons well before pressing them in.
Bleed proceedure is basically fill 1 syringe 1/2 full, another 1/4 full. Degass 1/2 full syringe by closing off the line either with the little line crimp or with your gloved finger and pull moderately until air bubbles form, and alternate with compressing it. Shake and hit it and generally get as much air out as you can but do not obsess over this step--you will never get to the point where you cannot form more bubbles. Pull brake pads, clean pistons, then push pistons in before installing bleed block. Attach 1/2 full syringe to caliper bleed port and 1/4 full syringe to lever bleed port. Push fluid up until caliper syringe is almost empty--you should see bubbles. Close lever bleed line by using the line crimp or by reinstalling the bleed port screw. Depress lever and hold it in place while alternating gently pulling on caliper syringe and gently pressing on it to try to get any air out. Hold lever as you push syringe and let lever out again. Create vacuum and pressure at lever syringe to remove bubbles. Be very gentle if (or seriously just push fluid up from caliper and call it a day) if you are suspicious of the conditions of the master cylinder. Clean the crap out of everything with isopropyl alcohol . Wash your hands real good at the end.
Thread
Thread Starter
Forum
Replies
Last Post
Bicyclehub
General Cycling Discussion
30
04-22-16 04:33 PM
Thumpic
Classic & Vintage
7
07-02-15 09:14 PM