250 Bleeding Dry Line Tips
- Thread starter RageD
- Start date
Still working on this. I tried the standard pumping method and lost the lever entirely 
went back to reverse bleeding with a syringe. It feels like it's definitely improved, but it's still far from stiff. How many times should I reverse bleed and sop? The answer is probably, "until it feels stiff" but do you guys know how much fluid you typically have to pump through? I've gone through about half a bottle now in reverse bleeding and I'm just now getting to the point where a "normal" pull doesn't fully rest on the bars (though it's close).
I have the lever zip tied again for while I'm at work today, but just wondering if there may be another problem somewhere else that I'm missing before I go wasting another bottle of fluid through the line.
Thanks!
went back to reverse bleeding with a syringe. It feels like it's definitely improved, but it's still far from stiff. How many times should I reverse bleed and sop? The answer is probably, "until it feels stiff" but do you guys know how much fluid you typically have to pump through? I've gone through about half a bottle now in reverse bleeding and I'm just now getting to the point where a "normal" pull doesn't fully rest on the bars (though it's close).I have the lever zip tied again for while I'm at work today, but just wondering if there may be another problem somewhere else that I'm missing before I go wasting another bottle of fluid through the line.
Thanks!
Still working on this. I tried the standard pumping method and lost the lever entirely
I have the lever zip tied again for while I'm at work today, but just wondering if there may be another problem somewhere else that I'm missing before I go wasting another bottle of fluid through the line.
Thanks!
Rig up something that will seal the reservoir but add a vacuum port, then put vacuum on the system, and it should draw all the air out of the system. You will not get a good lever while vacuum is applied, you'll need to perform this remove adapter pump up lever and repeat if necessary.
In two occasions, I have rebuilt the master cylinder and bled for hours... I mean hours... to no avail.
Stumped, and not one to throw money at a problem, I tried a different master cylinder. Instant fix. There was no air in the system.
The immediate remedy was replacement of the master cylinder. Not a typical result.
Something was physically wrong with the original master cylinders and they could not be rebuilt.
Not saying this applies to your case, but in the 100s of brakes I've bled, on two bikes I wasted a lot of time.
-BIG DAN
Stumped, and not one to throw money at a problem, I tried a different master cylinder. Instant fix. There was no air in the system.
The immediate remedy was replacement of the master cylinder. Not a typical result.
Something was physically wrong with the original master cylinders and they could not be rebuilt.
Not saying this applies to your case, but in the 100s of brakes I've bled, on two bikes I wasted a lot of time.
-BIG DAN
It is still fun to make them pile out of an elevator!
Were you able to get a lever at all with these masters? I am able to get a weak lever, it's just too spongy (far spongier than I would feel comfortable riding on).
Going to try some more tonight. I feel like this process is going to be never ending
I bled from both banjo's just now (at least 10 times a piece) and there doesn't seem to be any change still a pretty soft lever.
I took the caliper off the bike and started observing it. Something interesting (if totally unrelated) is that it seems only the bottom piston is raising when I pump up the brakes without anything there (see picture).
If I hold that bottom piston in place, the top one will happily raise instead. I noticed this by accident trying to see if I could mimic the situation where your buddy grabs your lever when you have working breaks (and you have to pry the pads apart). Spoiler: I could not reproduce this.
Does this indicate that there is air stuck in the cylinders? Would it be better for me to tear the whole thing down and try again from dry?
Thanks!
still a pretty soft lever.I took the caliper off the bike and started observing it. Something interesting (if totally unrelated) is that it seems only the bottom piston is raising when I pump up the brakes without anything there (see picture).
If I hold that bottom piston in place, the top one will happily raise instead. I noticed this by accident trying to see if I could mimic the situation where your buddy grabs your lever when you have working breaks (and you have to pry the pads apart). Spoiler: I could not reproduce this.
Does this indicate that there is air stuck in the cylinders? Would it be better for me to tear the whole thing down and try again from dry?
Thanks!
That is normal operation, the fluid passages are linked.
WAIT... Have you had the rotor between the pads while bleeding the brakes? -BIG DAN
I was just about to ask this question
Sneak one out and just start sniffing. Everyone else will do it too, and if you are the first one, no one suspects. Floyd used to ask "do you smell something burning?".
So I have not had my rotor between the brakes the whole time, but it was for most of the time. Either way, doesn't seem like much of a change.
Maybe today I'll open up the master again and reinspect it; I'm pretty sure I did everything that video described except everything was off the bike because I replaced the line.
Thanks for your help so far guys I hope I figure this out soon. The scent of brake fluid is becoming old xD
Maybe today I'll open up the master again and reinspect it; I'm pretty sure I did everything that video described except everything was off the bike because I replaced the line.
Thanks for your help so far guys
I hope I figure this out soon. The scent of brake fluid is becoming old xD