Question on bleeding SRAM hydraulic disc brakes . . .
#1
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Question on bleeding SRAM hydraulic disc brakes . . .
I picked up my first hydraulic disc brake bike the other day and have been researching brake bleeding procedures. I'm a former automotive mechanic, and the SRAM bleed procedures seem way overly complicated compared to the relatively simple bleeding method on vehicles. So, why can't you bleed SRAM hydraulic brakes like you do with a car?
- Undo bleed port at lever, insert hose/syringe
- Undo bleed port at caliper, insert hose & drain into a bucket
- Pressurize system via syringe at lever
- Reinsert bleed port at caliper
- Squeeze brake lever; release bleed port while under pressure, close before lever goes full home
- Repeat until bubbles are gone
#2
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I'm gonna go with 'because that's what works'. Also because of the proprietary fittings at both ends you pretty much have to do it their way. You probably could use the same procedure as a car but you have to use the syringes. Vacuum seems to do a pretty great job of getting air out.
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I picked up my first hydraulic disc brake bike the other day and have been researching brake bleeding procedures. I'm a former automotive mechanic, and the SRAM bleed procedures seem way overly complicated compared to the relatively simple bleeding method on vehicles. So, why can't you bleed SRAM hydraulic brakes like you do with a car?
- Undo bleed port at lever, insert hose/syringe
- Undo bleed port at caliper, insert hose & drain into a bucket
- Pressurize system via syringe at lever
- Reinsert bleed port at caliper
- Squeeze brake lever; release bleed port while under pressure, close before lever goes full home
- Repeat until bubbles are gone
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I did my first SRAM brake bleed earlier this year. I found this video extremely helpful:
I don't think I got it quite perfect, but it definitely helped a lot. I agree that it seems unnecessarily complicated, and I do not like the DOT fluid. Nonetheless, that's what this bike came with.
I don't think I got it quite perfect, but it definitely helped a lot. I agree that it seems unnecessarily complicated, and I do not like the DOT fluid. Nonetheless, that's what this bike came with.
#5
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I picked up my first hydraulic disc brake bike the other day and have been researching brake bleeding procedures. I'm a former automotive mechanic, and the SRAM bleed procedures seem way overly complicated compared to the relatively simple bleeding method on vehicles. So, why can't you bleed SRAM hydraulic brakes like you do with a car?
- Undo bleed port at lever, insert hose/syringe
- Undo bleed port at caliper, insert hose & drain into a bucket
- Pressurize system via syringe at lever
- Reinsert bleed port at caliper
- Squeeze brake lever; release bleed port while under pressure, close before lever goes full home
- Repeat until bubbles are gone
SRAM flat bar disks (formerly Avid) are a royal pain in the ass to bleed and you end up pumping the brake lever while feeding fluid in from the bottom port with the LARGE syringe. The road levers are more straight forward but remember the problem is even a small bubble that will stop the damn things from working.
The Shimano system is far more well engineered.
It took me 10 minutes to bleed both ends with my Shimano setup. It took me THREE days with the Avid and I think that bubbles were slowly working their way up to the top which is why it suddenly began working (or rather bleeding) with some effect. I believe that once your get it bled properly the first time that the wetting of the inside of the hydraulic lines makes it easier from then on.
#6
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I did my first SRAM brake bleed earlier this year. I found this video extremely helpful: https://www.youtube.com/watch?v=-_tGOPniwgo
I don't think I got it quite perfect, but it definitely helped a lot. I agree that it seems unnecessarily complicated, and I do not like the DOT fluid. Nonetheless, that's what this bike came with.
I don't think I got it quite perfect, but it definitely helped a lot. I agree that it seems unnecessarily complicated, and I do not like the DOT fluid. Nonetheless, that's what this bike came with.
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Shimano mineral oil gets very very dirty from pistons, bores, and o-rings. If you ride a bunch you should do a full bleed at least once a year. It obviously doesn't absorb water like DOT but it needs to be replaced once a year if not more.
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How do you do it in a shop environment for Shimano? At home I just push new fluid in from the “bottom” (calipers) and collect the old in the cup on the levers, discard that, and continue on my way. It has never failed me. Though recently a guy I know suggested I should drain the system, then reinstall the fluid.
#9
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It took me 10 minutes to bleed both ends with my Shimano setup. It took me THREE days with the Avid and I think that bubbles were slowly working their way up to the top which is why it suddenly began working (or rather bleeding) with some effect. I believe that once your get it bled properly the first time that the wetting of the inside of the hydraulic lines makes it easier from then on.
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Short hijack, on.
How do you do it in a shop environment for Shimano? At home I just push new fluid in from the “bottom” (calipers) and collect the old in the cup on the levers, discard that, and continue on my way. It has never failed me. Though recently a guy I know suggested I should drain the system, then reinstall the fluid.
How do you do it in a shop environment for Shimano? At home I just push new fluid in from the “bottom” (calipers) and collect the old in the cup on the levers, discard that, and continue on my way. It has never failed me. Though recently a guy I know suggested I should drain the system, then reinstall the fluid.
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